absence.rb

# frozen_string_literal: true

module ActiveModel
  module Validations
    # == \Active \Model Absence Validator
    class AbsenceValidator < EachValidator # :nodoc:
      def validate_each(record, attr_name, value)
        record.errors.add(attr_name, :present, **options) if value.present?
      end
    end

    module HelperMethods
      # Validates that the specified attributes are blank (as defined by
      # Object#present?). Happens by default on save.
      #
      #   class Person < ActiveRecord::Base
      #     validates_absence_of :first_name
      #   end
      #
      # The first_name attribute must be in the object and it must be blank.
      #
      # Configuration options:
      # * <tt>:message</tt> - A custom error message (default is: "must be blank").
      #
      # There is also a list of default options supported by every validator:
      # +:if+, +:unless+, +:on+, +:allow_nil+, +:allow_blank+, and +:strict+.
      # See ActiveModel::Validations::ClassMethods#validates for more information.
      def validates_absence_of(*attr_names)
        validates_with AbsenceValidator, _merge_attributes(attr_names)
      end
    end
  end
end

absence_validation_test.rb

# frozen_string_literal: true

require "cases/helper"
require "models/topic"
require "models/person"
require "models/custom_reader"

class AbsenceValidationTest < ActiveModel::TestCase
  teardown do
    Topic.clear_validators!
    Person.clear_validators!
    CustomReader.clear_validators!
  end

  def test_validates_absence_of
    Topic.validates_absence_of(:title, :content)
    t = Topic.new
    t.title = "foo"
    t.content = "bar"
    assert_predicate t, :invalid?
    assert_equal ["must be blank"], t.errors[:title]
    assert_equal ["must be blank"], t.errors[:content]
    t.title = ""
    t.content = "something"
    assert_predicate t, :invalid?
    assert_equal ["must be blank"], t.errors[:content]
    assert_equal [], t.errors[:title]
    t.content = ""
    assert_predicate t, :valid?
  end

  def test_validates_absence_of_with_array_arguments
    Topic.validates_absence_of %w(title content)
    t = Topic.new
    t.title = "foo"
    t.content = "bar"
    assert_predicate t, :invalid?
    assert_equal ["must be blank"], t.errors[:title]
    assert_equal ["must be blank"], t.errors[:content]
  end

  def test_validates_absence_of_with_custom_error_using_quotes
    Person.validates_absence_of :karma, message: "This string contains 'single' and \"double\" quotes"
    p = Person.new
    p.karma = "good"
    assert_predicate p, :invalid?
    assert_equal "This string contains 'single' and \"double\" quotes", p.errors[:karma].last
  end

  def test_validates_absence_of_for_ruby_class
    Person.validates_absence_of :karma
    p = Person.new
    p.karma = "good"
    assert_predicate p, :invalid?
    assert_equal ["must be blank"], p.errors[:karma]
    p.karma = nil
    assert_predicate p, :valid?
  end

  def test_validates_absence_of_for_ruby_class_with_custom_reader
    CustomReader.validates_absence_of :karma
    p = CustomReader.new
    p[:karma] = "excellent"
    assert_predicate p, :invalid?
    assert_equal ["must be blank"], p.errors[:karma]
    p[:karma] = ""
    assert_predicate p, :valid?
  end
end

acceptance.rb

# frozen_string_literal: true

module ActiveModel
  module Validations
    class AcceptanceValidator < EachValidator # :nodoc:
      def initialize(options)
        super({ allow_nil: true, accept: ["1", true] }.merge!(options))
        setup!(options[:class])
      end

      def validate_each(record, attribute, value)
        unless acceptable_option?(value)
          record.errors.add(attribute, :accepted, **options.except(:accept, :allow_nil))
        end
      end

      private
        def setup!(klass)
          define_attributes = LazilyDefineAttributes.new(attributes)
          klass.include(define_attributes) unless klass.included_modules.include?(define_attributes)
        end

        def acceptable_option?(value)
          Array(options[:accept]).include?(value)
        end

        class LazilyDefineAttributes < Module
          def initialize(attributes)
            @attributes = attributes.map(&:to_s)
          end

          def included(klass)
            @lock = Mutex.new
            mod = self

            define_method(:respond_to_missing?) do |method_name, include_private = false|
              mod.define_on(klass)
              super(method_name, include_private) || mod.matches?(method_name)
            end

            define_method(:method_missing) do |method_name, *args, &block|
              mod.define_on(klass)
              if mod.matches?(method_name)
                send(method_name, *args, &block)
              else
                super(method_name, *args, &block)
              end
            end
          end

          def matches?(method_name)
            attr_name = method_name.to_s.chomp("=")
            attributes.any? { |name| name == attr_name }
          end

          def define_on(klass)
            @lock&.synchronize do
              return unless @lock

              attr_readers = attributes.reject { |name| klass.attribute_method?(name) }
              attr_writers = attributes.reject { |name| klass.attribute_method?("#{name}=") }

              attr_reader(*attr_readers)
              attr_writer(*attr_writers)

              remove_method :respond_to_missing?
              remove_method :method_missing

              @lock = nil
            end
          end

          def ==(other)
            self.class == other.class && attributes == other.attributes
          end

          protected
            attr_reader :attributes
        end
    end

    module HelperMethods
      # Encapsulates the pattern of wanting to validate the acceptance of a
      # terms of service check box (or similar agreement).
      #
      #   class Person < ActiveRecord::Base
      #     validates_acceptance_of :terms_of_service
      #     validates_acceptance_of :eula, message: 'must be abided'
      #   end
      #
      # If the database column does not exist, the +terms_of_service+ attribute
      # is entirely virtual. This check is performed only if +terms_of_service+
      # is not +nil+ and by default on save.
      #
      # Configuration options:
      # * <tt>:message</tt> - A custom error message (default is: "must be
      #   accepted").
      # * <tt>:accept</tt> - Specifies a value that is considered accepted.
      #   Also accepts an array of possible values. The default value is
      #   an array ["1", true], which makes it easy to relate to an HTML
      #   checkbox. This should be set to, or include, +true+ if you are validating
      #   a database column, since the attribute is typecast from "1" to +true+
      #   before validation.
      #
      # There is also a list of default options supported by every validator:
      # +:if+, +:unless+, +:on+, +:allow_nil+, +:allow_blank+, and +:strict+.
      # See ActiveModel::Validations::ClassMethods#validates for more information.
      def validates_acceptance_of(*attr_names)
        validates_with AcceptanceValidator, _merge_attributes(attr_names)
      end
    end
  end
end

acceptance_validation_test.rb

# frozen_string_literal: true

require "cases/helper"

require "models/topic"
require "models/reply"
require "models/person"

class AcceptanceValidationTest < ActiveModel::TestCase
  teardown do
    self.class.send(:remove_const, :TestClass)
  end

  def test_terms_of_service_agreement_no_acceptance
    klass = define_test_class(Topic)
    klass.validates_acceptance_of(:terms_of_service)

    t = klass.new("title" => "We should not be confirmed")
    assert_predicate t, :valid?
  end

  def test_terms_of_service_agreement
    klass = define_test_class(Topic)
    klass.validates_acceptance_of(:terms_of_service)

    t = klass.new("title" => "We should be confirmed", "terms_of_service" => "")
    assert_predicate t, :invalid?
    assert_equal ["must be accepted"], t.errors[:terms_of_service]

    t.terms_of_service = "1"
    assert_predicate t, :valid?
  end

  def test_eula
    klass = define_test_class(Topic)
    klass.validates_acceptance_of(:eula, message: "must be abided")

    t = klass.new("title" => "We should be confirmed", "eula" => "")
    assert_predicate t, :invalid?
    assert_equal ["must be abided"], t.errors[:eula]

    t.eula = "1"
    assert_predicate t, :valid?
  end

  def test_terms_of_service_agreement_with_accept_value
    klass = define_test_class(Topic)
    klass.validates_acceptance_of(:terms_of_service, accept: "I agree.")

    t = klass.new("title" => "We should be confirmed", "terms_of_service" => "")
    assert_predicate t, :invalid?
    assert_equal ["must be accepted"], t.errors[:terms_of_service]

    t.terms_of_service = "I agree."
    assert_predicate t, :valid?
  end

  def test_terms_of_service_agreement_with_multiple_accept_values
    klass = define_test_class(Topic)
    klass.validates_acceptance_of(:terms_of_service, accept: [1, "I concur."])

    t = klass.new("title" => "We should be confirmed", "terms_of_service" => "")
    assert_predicate t, :invalid?
    assert_equal ["must be accepted"], t.errors[:terms_of_service]

    t.terms_of_service = 1
    assert_predicate t, :valid?

    t.terms_of_service = "I concur."
    assert_predicate t, :valid?
  end

  def test_validates_acceptance_of_for_ruby_class
    klass = define_test_class(Person)
    klass.validates_acceptance_of :karma

    p = klass.new
    p.karma = ""

    assert_predicate p, :invalid?
    assert_equal ["must be accepted"], p.errors[:karma]

    p.karma = "1"
    assert_predicate p, :valid?
  end

  def test_validates_acceptance_of_true
    klass = define_test_class(Topic)
    klass.validates_acceptance_of(:terms_of_service)

    assert_predicate klass.new(terms_of_service: true), :valid?
  end

  def test_lazy_attribute_module_included_only_once
    klass = define_test_class(Topic)
    assert_difference -> { klass.ancestors.count }, 2 do
      2.times do
        klass.validates_acceptance_of(:something_to_accept)
        assert klass.new.respond_to?(:something_to_accept)
      end
      2.times do
        klass.validates_acceptance_of(:something_else_to_accept)
        assert klass.new.respond_to?(:something_else_to_accept)
      end
    end
  end

  def test_lazy_attributes_module_included_again_if_needed
    klass = define_test_class(Topic)
    assert_difference -> { klass.ancestors.count }, 1 do
      klass.validates_acceptance_of(:something_to_accept)
    end
    topic = klass.new
    topic.something_to_accept
    assert_difference -> { klass.ancestors.count }, 1 do
      klass.validates_acceptance_of(:something_else_to_accept)
    end
    assert topic.respond_to?(:something_else_to_accept)
  end

  def test_lazy_attributes_respond_to?
    klass = define_test_class(Topic)
    klass.validates_acceptance_of(:terms_of_service)
    topic = klass.new
    threads = []
    2.times do
      threads << Thread.new do
        assert topic.respond_to?(:terms_of_service)
      end
    end
    threads.each(&:join)
  end

  private
    def define_test_class(parent)
      self.class.const_set(:TestClass, Class.new(parent))
    end
end

accepts_multiparameter_time.rb

# frozen_string_literal: true

module ActiveModel
  module Type
    module Helpers # :nodoc: all
      class AcceptsMultiparameterTime < Module
        module InstanceMethods
          def serialize(value)
            super(cast(value))
          end

          def cast(value)
            if value.is_a?(Hash)
              value_from_multiparameter_assignment(value)
            else
              super(value)
            end
          end

          def assert_valid_value(value)
            if value.is_a?(Hash)
              value_from_multiparameter_assignment(value)
            else
              super(value)
            end
          end

          def value_constructed_by_mass_assignment?(value)
            value.is_a?(Hash)
          end
        end

        def initialize(defaults: {})
          include InstanceMethods

          define_method(:value_from_multiparameter_assignment) do |values_hash|
            defaults.each do |k, v|
              values_hash[k] ||= v
            end
            return unless values_hash[1] && values_hash[2] && values_hash[3]
            values = values_hash.sort.map!(&:last)
            ::Time.public_send(default_timezone, *values)
          end
          private :value_from_multiparameter_assignment
        end
      end
    end
  end
end

access.rb

# frozen_string_literal: true

require "active_support/core_ext/enumerable"
require "active_support/core_ext/hash/indifferent_access"

module ActiveModel
  module Access # :nodoc:
    def slice(*methods)
      methods.flatten.index_with { |method| public_send(method) }.with_indifferent_access
    end

    def values_at(*methods)
      methods.flatten.map! { |method| public_send(method) }
    end
  end
end

access_test.rb

# frozen_string_literal: true

require "cases/helper"
require "active_support/core_ext/hash/indifferent_access"

class AccessTest < ActiveModel::TestCase
  class Point
    include ActiveModel::Access

    def initialize(*vector)
      @vector = vector
    end

    def x
      @vector[0]
    end

    def y
      @vector[1]
    end

    def z
      @vector[2]
    end
  end

  setup do
    @point = Point.new(123, 456, 789)
  end

  test "slice" do
    expected = { z: @point.z, x: @point.x }.with_indifferent_access
    actual = @point.slice(:z, :x)

    assert_equal expected.keys, actual.keys

    expected.each do |key, value|
      assert_equal value, actual[key.to_s]
      assert_equal value, actual[key.to_sym]
    end
  end

  test "slice with array" do
    expected = { z: @point.z, x: @point.x }.with_indifferent_access
    assert_equal expected, @point.slice([:z, :x])
  end

  test "values_at" do
    assert_equal [@point.x, @point.z], @point.values_at(:x, :z)
    assert_equal [@point.z, @point.x], @point.values_at(:z, :x)
  end

  test "values_at with array" do
    assert_equal [@point.x, @point.z], @point.values_at([:x, :z])
    assert_equal [@point.z, @point.x], @point.values_at([:z, :x])
  end
end

account.rb

# frozen_string_literal: true

class Account
  include ActiveModel::ForbiddenAttributesProtection

  public :sanitize_for_mass_assignment
end

active_model.rb

# frozen_string_literal: true

#--
# Copyright (c) 2004-2022 David Heinemeier Hansson
#
# Permission is hereby granted, free of charge, to any person obtaining
# a copy of this software and associated documentation files (the
# "Software"), to deal in the Software without restriction, including
# without limitation the rights to use, copy, modify, merge, publish,
# distribute, sublicense, and/or sell copies of the Software, and to
# permit persons to whom the Software is furnished to do so, subject to
# the following conditions:
#
# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
# LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
#++

require "active_support"
require "active_support/rails"
require "active_model/version"

module ActiveModel
  extend ActiveSupport::Autoload

  autoload :Access
  autoload :API
  autoload :Attribute
  autoload :Attributes
  autoload :AttributeAssignment
  autoload :AttributeMethods
  autoload :BlockValidator, "active_model/validator"
  autoload :Callbacks
  autoload :Conversion
  autoload :Dirty
  autoload :EachValidator, "active_model/validator"
  autoload :ForbiddenAttributesProtection
  autoload :Lint
  autoload :Model
  autoload :Name, "active_model/naming"
  autoload :Naming
  autoload :SecurePassword
  autoload :Serialization
  autoload :Translation
  autoload :Type
  autoload :Validations
  autoload :Validator

  eager_autoload do
    autoload :Errors
    autoload :Error
    autoload :RangeError, "active_model/errors"
    autoload :StrictValidationFailed, "active_model/errors"
    autoload :UnknownAttributeError, "active_model/errors"
  end

  module Serializers
    extend ActiveSupport::Autoload

    eager_autoload do
      autoload :JSON
    end
  end

  def self.eager_load!
    super
    ActiveModel::Serializers.eager_load!
  end
end

ActiveSupport.on_load(:i18n) do
  I18n.load_path << File.expand_path("active_model/locale/en.yml", __dir__)
end

api.rb

# frozen_string_literal: true

module ActiveModel
  # == Active \Model \API
  #
  # Includes the required interface for an object to interact with
  # Action Pack and Action View, using different Active Model modules.
  # It includes model name introspections, conversions, translations, and
  # validations. Besides that, it allows you to initialize the object with a
  # hash of attributes, pretty much like Active Record does.
  #
  # A minimal implementation could be:
  #
  #   class Person
  #     include ActiveModel::API
  #     attr_accessor :name, :age
  #   end
  #
  #   person = Person.new(name: 'bob', age: '18')
  #   person.name # => "bob"
  #   person.age  # => "18"
  #
  # Note that, by default, <tt>ActiveModel::API</tt> implements <tt>persisted?</tt>
  # to return +false+, which is the most common case. You may want to override
  # it in your class to simulate a different scenario:
  #
  #   class Person
  #     include ActiveModel::API
  #     attr_accessor :id, :name
  #
  #     def persisted?
  #       self.id.present?
  #     end
  #   end
  #
  #   person = Person.new(id: 1, name: 'bob')
  #   person.persisted? # => true
  #
  # Also, if for some reason you need to run code on <tt>initialize</tt>, make
  # sure you call +super+ if you want the attributes hash initialization to
  # happen.
  #
  #   class Person
  #     include ActiveModel::API
  #     attr_accessor :id, :name, :omg
  #
  #     def initialize(attributes={})
  #       super
  #       @omg ||= true
  #     end
  #   end
  #
  #   person = Person.new(id: 1, name: 'bob')
  #   person.omg # => true
  #
  # For more detailed information on other functionalities available, please
  # refer to the specific modules included in <tt>ActiveModel::API</tt>
  # (see below).
  module API
    extend ActiveSupport::Concern
    include ActiveModel::AttributeAssignment
    include ActiveModel::Validations
    include ActiveModel::Conversion

    included do
      extend ActiveModel::Naming
      extend ActiveModel::Translation
    end

    # Initializes a new model with the given +params+.
    #
    #   class Person
    #     include ActiveModel::API
    #     attr_accessor :name, :age
    #   end
    #
    #   person = Person.new(name: 'bob', age: '18')
    #   person.name # => "bob"
    #   person.age  # => "18"
    def initialize(attributes = {})
      assign_attributes(attributes) if attributes

      super()
    end

    # Indicates if the model is persisted. Default is +false+.
    #
    #  class Person
    #    include ActiveModel::API
    #    attr_accessor :id, :name
    #  end
    #
    #  person = Person.new(id: 1, name: 'bob')
    #  person.persisted? # => false
    def persisted?
      false
    end
  end
end

api_test.rb

# frozen_string_literal: true

require "cases/helper"

class APITest < ActiveModel::TestCase
  include ActiveModel::Lint::Tests

  module DefaultValue
    def self.included(klass)
      klass.class_eval { attr_accessor :hello }
    end

    def initialize(*args)
      @attr ||= "default value"
      super
    end
  end

  class BasicModel
    include DefaultValue
    include ActiveModel::API
    attr_accessor :attr
  end

  class BasicModelWithReversedMixins
    include ActiveModel::API
    include DefaultValue
    attr_accessor :attr
  end

  class SimpleModel
    include ActiveModel::API
    attr_accessor :attr
  end

  def setup
    @model = BasicModel.new
  end

  def test_initialize_with_params
    object = BasicModel.new(attr: "value")
    assert_equal "value", object.attr
  end

  def test_initialize_with_params_and_mixins_reversed
    object = BasicModelWithReversedMixins.new(attr: "value")
    assert_equal "value", object.attr
  end

  def test_initialize_with_nil_or_empty_hash_params_does_not_explode
    assert_nothing_raised do
      BasicModel.new()
      BasicModel.new(nil)
      BasicModel.new({})
      SimpleModel.new(attr: "value")
    end
  end

  def test_persisted_is_always_false
    object = BasicModel.new(attr: "value")
    assert_not object.persisted?
  end

  def test_mixin_inclusion_chain
    object = BasicModel.new
    assert_equal "default value", object.attr
  end

  def test_mixin_initializer_when_args_exist
    object = BasicModel.new(hello: "world")
    assert_equal "world", object.hello
  end

  def test_mixin_initializer_when_args_dont_exist
    assert_raises(ActiveModel::UnknownAttributeError) do
      SimpleModel.new(hello: "world")
    end
  end
end

attribute.rb

# frozen_string_literal: true

require "active_support/core_ext/object/duplicable"

module ActiveModel
  class Attribute # :nodoc:
    class << self
      def from_database(name, value_before_type_cast, type, value = nil)
        FromDatabase.new(name, value_before_type_cast, type, nil, value)
      end

      def from_user(name, value_before_type_cast, type, original_attribute = nil)
        FromUser.new(name, value_before_type_cast, type, original_attribute)
      end

      def with_cast_value(name, value_before_type_cast, type)
        WithCastValue.new(name, value_before_type_cast, type)
      end

      def null(name)
        Null.new(name)
      end

      def uninitialized(name, type)
        Uninitialized.new(name, type)
      end
    end

    attr_reader :name, :value_before_type_cast, :type

    # This method should not be called directly.
    # Use #from_database or #from_user
    def initialize(name, value_before_type_cast, type, original_attribute = nil, value = nil)
      @name = name
      @value_before_type_cast = value_before_type_cast
      @type = type
      @original_attribute = original_attribute
      @value = value unless value.nil?
    end

    def value
      # `defined?` is cheaper than `||=` when we get back falsy values
      @value = type_cast(value_before_type_cast) unless defined?(@value)
      @value
    end

    def original_value
      if assigned?
        original_attribute.original_value
      else
        type_cast(value_before_type_cast)
      end
    end

    def value_for_database
      type.serialize(value)
    end

    def serializable?(&block)
      type.serializable?(value, &block)
    end

    def changed?
      changed_from_assignment? || changed_in_place?
    end

    def changed_in_place?
      has_been_read? && type.changed_in_place?(original_value_for_database, value)
    end

    def forgetting_assignment
      with_value_from_database(value_for_database)
    end

    def with_value_from_user(value)
      type.assert_valid_value(value)
      self.class.from_user(name, value, type, original_attribute || self)
    end

    def with_value_from_database(value)
      self.class.from_database(name, value, type)
    end

    def with_cast_value(value)
      self.class.with_cast_value(name, value, type)
    end

    def with_type(type)
      if changed_in_place?
        with_value_from_user(value).with_type(type)
      else
        self.class.new(name, value_before_type_cast, type, original_attribute)
      end
    end

    def type_cast(*)
      raise NotImplementedError
    end

    def initialized?
      true
    end

    def came_from_user?
      false
    end

    def has_been_read?
      defined?(@value)
    end

    def ==(other)
      self.class == other.class &&
        name == other.name &&
        value_before_type_cast == other.value_before_type_cast &&
        type == other.type
    end
    alias eql? ==

    def hash
      [self.class, name, value_before_type_cast, type].hash
    end

    def init_with(coder)
      @name = coder["name"]
      @value_before_type_cast = coder["value_before_type_cast"]
      @type = coder["type"]
      @original_attribute = coder["original_attribute"]
      @value = coder["value"] if coder.map.key?("value")
    end

    def encode_with(coder)
      coder["name"] = name
      coder["value_before_type_cast"] = value_before_type_cast unless value_before_type_cast.nil?
      coder["type"] = type if type
      coder["original_attribute"] = original_attribute if original_attribute
      coder["value"] = value if defined?(@value)
    end

    def original_value_for_database
      if assigned?
        original_attribute.original_value_for_database
      else
        _original_value_for_database
      end
    end

    private
      attr_reader :original_attribute
      alias :assigned? :original_attribute

      def initialize_dup(other)
        if defined?(@value) && @value.duplicable?
          @value = @value.dup
        end
      end

      def changed_from_assignment?
        assigned? && type.changed?(original_value, value, value_before_type_cast)
      end

      def _original_value_for_database
        type.serialize(original_value)
      end

      class FromDatabase < Attribute # :nodoc:
        def type_cast(value)
          type.deserialize(value)
        end

        private
          def _original_value_for_database
            value_before_type_cast
          end
      end

      class FromUser < Attribute # :nodoc:
        def type_cast(value)
          type.cast(value)
        end

        def came_from_user?
          !type.value_constructed_by_mass_assignment?(value_before_type_cast)
        end
      end

      class WithCastValue < Attribute # :nodoc:
        def type_cast(value)
          value
        end

        def changed_in_place?
          false
        end
      end

      class Null < Attribute # :nodoc:
        def initialize(name)
          super(name, nil, Type.default_value)
        end

        def type_cast(*)
          nil
        end

        def with_type(type)
          self.class.with_cast_value(name, nil, type)
        end

        def with_value_from_database(value)
          raise ActiveModel::MissingAttributeError, "can't write unknown attribute `#{name}`"
        end
        alias_method :with_value_from_user, :with_value_from_database
        alias_method :with_cast_value, :with_value_from_database
      end

      class Uninitialized < Attribute # :nodoc:
        UNINITIALIZED_ORIGINAL_VALUE = Object.new

        def initialize(name, type)
          super(name, nil, type)
        end

        def value
          if block_given?
            yield name
          end
        end

        def original_value
          UNINITIALIZED_ORIGINAL_VALUE
        end

        def value_for_database
        end

        def initialized?
          false
        end

        def forgetting_assignment
          dup
        end

        def with_type(type)
          self.class.new(name, type)
        end
      end

      private_constant :FromDatabase, :FromUser, :Null, :Uninitialized, :WithCastValue
  end
end

attribute_assignment.rb

# frozen_string_literal: true

require "active_support/core_ext/hash/keys"

module ActiveModel
  module AttributeAssignment
    include ActiveModel::ForbiddenAttributesProtection

    # Allows you to set all the attributes by passing in a hash of attributes with
    # keys matching the attribute names.
    #
    # If the passed hash responds to <tt>permitted?</tt> method and the return value
    # of this method is +false+ an <tt>ActiveModel::ForbiddenAttributesError</tt>
    # exception is raised.
    #
    #   class Cat
    #     include ActiveModel::AttributeAssignment
    #     attr_accessor :name, :status
    #   end
    #
    #   cat = Cat.new
    #   cat.assign_attributes(name: "Gorby", status: "yawning")
    #   cat.name # => 'Gorby'
    #   cat.status # => 'yawning'
    #   cat.assign_attributes(status: "sleeping")
    #   cat.name # => 'Gorby'
    #   cat.status # => 'sleeping'
    def assign_attributes(new_attributes)
      unless new_attributes.respond_to?(:each_pair)
        raise ArgumentError, "When assigning attributes, you must pass a hash as an argument, #{new_attributes.class} passed."
      end
      return if new_attributes.empty?

      _assign_attributes(sanitize_for_mass_assignment(new_attributes))
    end

    alias attributes= assign_attributes

    private
      def _assign_attributes(attributes)
        attributes.each do |k, v|
          _assign_attribute(k, v)
        end
      end

      def _assign_attribute(k, v)
        setter = :"#{k}="
        if respond_to?(setter)
          public_send(setter, v)
        else
          raise UnknownAttributeError.new(self, k.to_s)
        end
      end
  end
end

attribute_assignment_test.rb

# frozen_string_literal: true

require "cases/helper"
require "active_support/core_ext/hash/indifferent_access"
require "active_support/hash_with_indifferent_access"

class AttributeAssignmentTest < ActiveModel::TestCase
  class Model
    include ActiveModel::AttributeAssignment

    attr_accessor :name, :description

    def initialize(attributes = {})
      assign_attributes(attributes)
    end

    def broken_attribute=(value)
      raise ErrorFromAttributeWriter
    end

    private
      attr_writer :metadata
  end

  class ErrorFromAttributeWriter < StandardError
  end

  class ProtectedParams
    attr_accessor :permitted
    alias :permitted? :permitted

    delegate :keys, :key?, :has_key?, :empty?, to: :@parameters

    def initialize(attributes)
      @parameters = attributes.with_indifferent_access
      @permitted = false
    end

    def permit!
      @permitted = true
      self
    end

    def [](key)
      @parameters[key]
    end

    def to_h
      @parameters
    end

    def each_pair(&block)
      @parameters.each_pair(&block)
    end

    def dup
      super.tap do |duplicate|
        duplicate.instance_variable_set :@permitted, permitted?
      end
    end
  end

  test "simple assignment" do
    model = Model.new

    model.assign_attributes(name: "hello", description: "world")
    assert_equal "hello", model.name
    assert_equal "world", model.description
  end

  test "simple assignment alias" do
    model = Model.new

    model.attributes = { name: "hello", description: "world" }
    assert_equal "hello", model.name
    assert_equal "world", model.description
  end

  test "assign non-existing attribute" do
    model = Model.new
    error = assert_raises(ActiveModel::UnknownAttributeError) do
      model.assign_attributes(hz: 1)
    end

    assert_equal model, error.record
    assert_equal "hz", error.attribute
  end

  test "assign private attribute" do
    model = Model.new
    assert_raises(ActiveModel::UnknownAttributeError) do
      model.assign_attributes(metadata: { a: 1 })
    end
  end

  test "does not swallow errors raised in an attribute writer" do
    assert_raises(ErrorFromAttributeWriter) do
      Model.new(broken_attribute: 1)
    end
  end

  test "an ArgumentError is raised if a non-hash-like object is passed" do
    err = assert_raises(ArgumentError) do
      Model.new(1)
    end

    assert_equal("When assigning attributes, you must pass a hash as an argument, Integer passed.", err.message)
  end

  test "forbidden attributes cannot be used for mass assignment" do
    params = ProtectedParams.new(name: "Guille", description: "m")

    assert_raises(ActiveModel::ForbiddenAttributesError) do
      Model.new(params)
    end
  end

  test "permitted attributes can be used for mass assignment" do
    params = ProtectedParams.new(name: "Guille", description: "desc")
    params.permit!
    model = Model.new(params)

    assert_equal "Guille", model.name
    assert_equal "desc", model.description
  end

  test "regular hash should still be used for mass assignment" do
    model = Model.new(name: "Guille", description: "m")

    assert_equal "Guille", model.name
    assert_equal "m", model.description
  end

  test "assigning no attributes should not raise, even if the hash is un-permitted" do
    model = Model.new
    assert_nil model.assign_attributes(ProtectedParams.new({}))
  end
end

attribute_methods.rb

# frozen_string_literal: true

require "concurrent/map"

module ActiveModel
  # Raised when an attribute is not defined.
  #
  #   class User < ActiveRecord::Base
  #     has_many :pets
  #   end
  #
  #   user = User.first
  #   user.pets.select(:id).first.user_id
  #   # => ActiveModel::MissingAttributeError: missing attribute: user_id
  class MissingAttributeError < NoMethodError
  end

  # == Active \Model \Attribute \Methods
  #
  # Provides a way to add prefixes and suffixes to your methods as
  # well as handling the creation of <tt>ActiveRecord::Base</tt>-like
  # class methods such as +table_name+.
  #
  # The requirements to implement <tt>ActiveModel::AttributeMethods</tt> are to:
  #
  # * <tt>include ActiveModel::AttributeMethods</tt> in your class.
  # * Call each of its methods you want to add, such as +attribute_method_suffix+
  #   or +attribute_method_prefix+.
  # * Call +define_attribute_methods+ after the other methods are called.
  # * Define the various generic +_attribute+ methods that you have declared.
  # * Define an +attributes+ method which returns a hash with each
  #   attribute name in your model as hash key and the attribute value as hash value.
  #   Hash keys must be strings.
  #
  # A minimal implementation could be:
  #
  #   class Person
  #     include ActiveModel::AttributeMethods
  #
  #     attribute_method_affix  prefix: 'reset_', suffix: '_to_default!'
  #     attribute_method_suffix '_contrived?'
  #     attribute_method_prefix 'clear_'
  #     define_attribute_methods :name
  #
  #     attr_accessor :name
  #
  #     def attributes
  #       { 'name' => @name }
  #     end
  #
  #     private
  #
  #     def attribute_contrived?(attr)
  #       true
  #     end
  #
  #     def clear_attribute(attr)
  #       send("#{attr}=", nil)
  #     end
  #
  #     def reset_attribute_to_default!(attr)
  #       send("#{attr}=", 'Default Name')
  #     end
  #   end
  module AttributeMethods
    extend ActiveSupport::Concern

    NAME_COMPILABLE_REGEXP = /\A[a-zA-Z_]\w*[!?=]?\z/
    CALL_COMPILABLE_REGEXP = /\A[a-zA-Z_]\w*[!?]?\z/
    FORWARD_PARAMETERS = "*args"

    included do
      class_attribute :attribute_aliases, instance_writer: false, default: {}
      class_attribute :attribute_method_patterns, instance_writer: false, default: [ ClassMethods::AttributeMethodPattern.new ]
    end

    module ClassMethods
      # Declares a method available for all attributes with the given prefix.
      # Uses +method_missing+ and <tt>respond_to?</tt> to rewrite the method.
      #
      #   #{prefix}#{attr}(*args, &block)
      #
      # to
      #
      #   #{prefix}attribute(#{attr}, *args, &block)
      #
      # An instance method <tt>#{prefix}attribute</tt> must exist and accept
      # at least the +attr+ argument.
      #
      #   class Person
      #     include ActiveModel::AttributeMethods
      #
      #     attr_accessor :name
      #     attribute_method_prefix 'clear_'
      #     define_attribute_methods :name
      #
      #     private
      #
      #     def clear_attribute(attr)
      #       send("#{attr}=", nil)
      #     end
      #   end
      #
      #   person = Person.new
      #   person.name = 'Bob'
      #   person.name          # => "Bob"
      #   person.clear_name
      #   person.name          # => nil
      def attribute_method_prefix(*prefixes, parameters: nil)
        self.attribute_method_patterns += prefixes.map! { |prefix| AttributeMethodPattern.new(prefix: prefix, parameters: parameters) }
        undefine_attribute_methods
      end

      # Declares a method available for all attributes with the given suffix.
      # Uses +method_missing+ and <tt>respond_to?</tt> to rewrite the method.
      #
      #   #{attr}#{suffix}(*args, &block)
      #
      # to
      #
      #   attribute#{suffix}(#{attr}, *args, &block)
      #
      # An <tt>attribute#{suffix}</tt> instance method must exist and accept at
      # least the +attr+ argument.
      #
      #   class Person
      #     include ActiveModel::AttributeMethods
      #
      #     attr_accessor :name
      #     attribute_method_suffix '_short?'
      #     define_attribute_methods :name
      #
      #     private
      #
      #     def attribute_short?(attr)
      #       send(attr).length < 5
      #     end
      #   end
      #
      #   person = Person.new
      #   person.name = 'Bob'
      #   person.name          # => "Bob"
      #   person.name_short?   # => true
      def attribute_method_suffix(*suffixes, parameters: nil)
        self.attribute_method_patterns += suffixes.map! { |suffix| AttributeMethodPattern.new(suffix: suffix, parameters: parameters) }
        undefine_attribute_methods
      end

      # Declares a method available for all attributes with the given prefix
      # and suffix. Uses +method_missing+ and <tt>respond_to?</tt> to rewrite
      # the method.
      #
      #   #{prefix}#{attr}#{suffix}(*args, &block)
      #
      # to
      #
      #   #{prefix}attribute#{suffix}(#{attr}, *args, &block)
      #
      # An <tt>#{prefix}attribute#{suffix}</tt> instance method must exist and
      # accept at least the +attr+ argument.
      #
      #   class Person
      #     include ActiveModel::AttributeMethods
      #
      #     attr_accessor :name
      #     attribute_method_affix prefix: 'reset_', suffix: '_to_default!'
      #     define_attribute_methods :name
      #
      #     private
      #
      #     def reset_attribute_to_default!(attr)
      #       send("#{attr}=", 'Default Name')
      #     end
      #   end
      #
      #   person = Person.new
      #   person.name                         # => 'Gem'
      #   person.reset_name_to_default!
      #   person.name                         # => 'Default Name'
      def attribute_method_affix(*affixes)
        self.attribute_method_patterns += affixes.map! { |affix| AttributeMethodPattern.new(**affix) }
        undefine_attribute_methods
      end

      # Allows you to make aliases for attributes.
      #
      #   class Person
      #     include ActiveModel::AttributeMethods
      #
      #     attr_accessor :name
      #     attribute_method_suffix '_short?'
      #     define_attribute_methods :name
      #
      #     alias_attribute :nickname, :name
      #
      #     private
      #
      #     def attribute_short?(attr)
      #       send(attr).length < 5
      #     end
      #   end
      #
      #   person = Person.new
      #   person.name = 'Bob'
      #   person.name            # => "Bob"
      #   person.nickname        # => "Bob"
      #   person.name_short?     # => true
      #   person.nickname_short? # => true
      def alias_attribute(new_name, old_name)
        self.attribute_aliases = attribute_aliases.merge(new_name.to_s => old_name.to_s)
        ActiveSupport::CodeGenerator.batch(self, __FILE__, __LINE__) do |code_generator|
          attribute_method_patterns.each do |pattern|
            method_name = pattern.method_name(new_name).to_s
            target_name = pattern.method_name(old_name).to_s
            parameters = pattern.parameters

            mangled_name = target_name
            unless NAME_COMPILABLE_REGEXP.match?(target_name)
              mangled_name = "__temp__#{target_name.unpack1("h*")}"
            end

            code_generator.define_cached_method(method_name, as: mangled_name, namespace: :alias_attribute) do |batch|
              body = if CALL_COMPILABLE_REGEXP.match?(target_name)
                "self.#{target_name}(#{parameters || ''})"
              else
                call_args = [":'#{target_name}'"]
                call_args << parameters if parameters
                "send(#{call_args.join(", ")})"
              end

              modifier = pattern.parameters == FORWARD_PARAMETERS ? "ruby2_keywords " : ""

              batch <<
                "#{modifier}def #{mangled_name}(#{parameters || ''})" <<
                body <<
                "end"
            end
          end
        end
      end

      # Is +new_name+ an alias?
      def attribute_alias?(new_name)
        attribute_aliases.key? new_name.to_s
      end

      # Returns the original name for the alias +name+
      def attribute_alias(name)
        attribute_aliases[name.to_s]
      end

      # Declares the attributes that should be prefixed and suffixed by
      # <tt>ActiveModel::AttributeMethods</tt>.
      #
      # To use, pass attribute names (as strings or symbols). Be sure to declare
      # +define_attribute_methods+ after you define any prefix, suffix, or affix
      # methods, or they will not hook in.
      #
      #   class Person
      #     include ActiveModel::AttributeMethods
      #
      #     attr_accessor :name, :age, :address
      #     attribute_method_prefix 'clear_'
      #
      #     # Call to define_attribute_methods must appear after the
      #     # attribute_method_prefix, attribute_method_suffix or
      #     # attribute_method_affix declarations.
      #     define_attribute_methods :name, :age, :address
      #
      #     private
      #
      #     def clear_attribute(attr)
      #       send("#{attr}=", nil)
      #     end
      #   end
      def define_attribute_methods(*attr_names)
        ActiveSupport::CodeGenerator.batch(generated_attribute_methods, __FILE__, __LINE__) do |owner|
          attr_names.flatten.each { |attr_name| define_attribute_method(attr_name, _owner: owner) }
        end
      end

      # Declares an attribute that should be prefixed and suffixed by
      # <tt>ActiveModel::AttributeMethods</tt>.
      #
      # To use, pass an attribute name (as string or symbol). Be sure to declare
      # +define_attribute_method+ after you define any prefix, suffix or affix
      # method, or they will not hook in.
      #
      #   class Person
      #     include ActiveModel::AttributeMethods
      #
      #     attr_accessor :name
      #     attribute_method_suffix '_short?'
      #
      #     # Call to define_attribute_method must appear after the
      #     # attribute_method_prefix, attribute_method_suffix or
      #     # attribute_method_affix declarations.
      #     define_attribute_method :name
      #
      #     private
      #
      #     def attribute_short?(attr)
      #       send(attr).length < 5
      #     end
      #   end
      #
      #   person = Person.new
      #   person.name = 'Bob'
      #   person.name        # => "Bob"
      #   person.name_short? # => true
      def define_attribute_method(attr_name, _owner: generated_attribute_methods)
        ActiveSupport::CodeGenerator.batch(_owner, __FILE__, __LINE__) do |owner|
          attribute_method_patterns.each do |pattern|
            method_name = pattern.method_name(attr_name)

            unless instance_method_already_implemented?(method_name)
              generate_method = "define_method_#{pattern.proxy_target}"

              if respond_to?(generate_method, true)
                send(generate_method, attr_name.to_s, owner: owner)
              else
                define_proxy_call(owner, method_name, pattern.proxy_target, pattern.parameters, attr_name.to_s, namespace: :active_model_proxy)
              end
            end
          end
          attribute_method_patterns_cache.clear
        end
      end

      # Removes all the previously dynamically defined methods from the class.
      #
      #   class Person
      #     include ActiveModel::AttributeMethods
      #
      #     attr_accessor :name
      #     attribute_method_suffix '_short?'
      #     define_attribute_method :name
      #
      #     private
      #
      #     def attribute_short?(attr)
      #       send(attr).length < 5
      #     end
      #   end
      #
      #   person = Person.new
      #   person.name = 'Bob'
      #   person.name_short? # => true
      #
      #   Person.undefine_attribute_methods
      #
      #   person.name_short? # => NoMethodError
      def undefine_attribute_methods
        generated_attribute_methods.module_eval do
          undef_method(*instance_methods)
        end
        attribute_method_patterns_cache.clear
      end

      private
        def generated_attribute_methods
          @generated_attribute_methods ||= Module.new.tap { |mod| include mod }
        end

        def instance_method_already_implemented?(method_name)
          generated_attribute_methods.method_defined?(method_name)
        end

        # The methods +method_missing+ and +respond_to?+ of this module are
        # invoked often in a typical rails, both of which invoke the method
        # +matched_attribute_method+. The latter method iterates through an
        # array doing regular expression matches, which results in a lot of
        # object creations. Most of the time it returns a +nil+ match. As the
        # match result is always the same given a +method_name+, this cache is
        # used to alleviate the GC, which ultimately also speeds up the app
        # significantly (in our case our test suite finishes 10% faster with
        # this cache).
        def attribute_method_patterns_cache
          @attribute_method_patterns_cache ||= Concurrent::Map.new(initial_capacity: 4)
        end

        def attribute_method_patterns_matching(method_name)
          attribute_method_patterns_cache.compute_if_absent(method_name) do
            attribute_method_patterns.filter_map { |pattern| pattern.match(method_name) }
          end
        end

        # Define a method `name` in `mod` that dispatches to `send`
        # using the given `extra` args. This falls back on `send`
        # if the called name cannot be compiled.
        def define_proxy_call(code_generator, name, proxy_target, parameters, *call_args, namespace:)
          mangled_name = name
          unless NAME_COMPILABLE_REGEXP.match?(name)
            mangled_name = "__temp__#{name.unpack1("h*")}"
          end

          code_generator.define_cached_method(name, as: mangled_name, namespace: namespace) do |batch|
            call_args.map!(&:inspect)
            call_args << parameters if parameters

            body = if CALL_COMPILABLE_REGEXP.match?(proxy_target)
              "self.#{proxy_target}(#{call_args.join(", ")})"
            else
              call_args.unshift(":'#{proxy_target}'")
              "send(#{call_args.join(", ")})"
            end

            modifier = parameters == FORWARD_PARAMETERS ? "ruby2_keywords " : ""

            batch <<
              "#{modifier}def #{mangled_name}(#{parameters || ''})" <<
              body <<
              "end"
          end
        end

        class AttributeMethodPattern # :nodoc:
          attr_reader :prefix, :suffix, :proxy_target, :parameters

          AttributeMethod = Struct.new(:proxy_target, :attr_name)

          def initialize(prefix: "", suffix: "", parameters: nil)
            @prefix = prefix
            @suffix = suffix
            @parameters = parameters.nil? ? FORWARD_PARAMETERS : parameters
            @regex = /^(?:#{Regexp.escape(@prefix)})(.*)(?:#{Regexp.escape(@suffix)})$/
            @proxy_target = "#{@prefix}attribute#{@suffix}"
            @method_name = "#{prefix}%s#{suffix}"
          end

          def match(method_name)
            if @regex =~ method_name
              AttributeMethod.new(proxy_target, $1)
            end
          end

          def method_name(attr_name)
            @method_name % attr_name
          end
        end
    end

    # Allows access to the object attributes, which are held in the hash
    # returned by <tt>attributes</tt>, as though they were first-class
    # methods. So a +Person+ class with a +name+ attribute can for example use
    # <tt>Person#name</tt> and <tt>Person#name=</tt> and never directly use
    # the attributes hash -- except for multiple assignments with
    # <tt>ActiveRecord::Base#attributes=</tt>.
    #
    # It's also possible to instantiate related objects, so a <tt>Client</tt>
    # class belonging to the +clients+ table with a +master_id+ foreign key
    # can instantiate master through <tt>Client#master</tt>.
    def method_missing(method, *args, &block)
      if respond_to_without_attributes?(method, true)
        super
      else
        match = matched_attribute_method(method.to_s)
        match ? attribute_missing(match, *args, &block) : super
      end
    end
    ruby2_keywords(:method_missing)

    # +attribute_missing+ is like +method_missing+, but for attributes. When
    # +method_missing+ is called we check to see if there is a matching
    # attribute method. If so, we tell +attribute_missing+ to dispatch the
    # attribute. This method can be overloaded to customize the behavior.
    def attribute_missing(match, *args, &block)
      __send__(match.proxy_target, match.attr_name, *args, &block)
    end

    # A +Person+ instance with a +name+ attribute can ask
    # <tt>person.respond_to?(:name)</tt>, <tt>person.respond_to?(:name=)</tt>,
    # and <tt>person.respond_to?(:name?)</tt> which will all return +true+.
    alias :respond_to_without_attributes? :respond_to?
    def respond_to?(method, include_private_methods = false)
      if super
        true
      elsif !include_private_methods && super(method, true)
        # If we're here then we haven't found among non-private methods
        # but found among all methods. Which means that the given method is private.
        false
      else
        !matched_attribute_method(method.to_s).nil?
      end
    end

    private
      def attribute_method?(attr_name)
        respond_to_without_attributes?(:attributes) && attributes.include?(attr_name)
      end

      # Returns a struct representing the matching attribute method.
      # The struct's attributes are prefix, base and suffix.
      def matched_attribute_method(method_name)
        matches = self.class.send(:attribute_method_patterns_matching, method_name)
        matches.detect { |match| attribute_method?(match.attr_name) }
      end

      def missing_attribute(attr_name, stack)
        raise ActiveModel::MissingAttributeError, "missing attribute: #{attr_name}", stack
      end

      def _read_attribute(attr)
        __send__(attr)
      end

      module AttrNames # :nodoc:
        DEF_SAFE_NAME = /\A[a-zA-Z_]\w*\z/

        # We want to generate the methods via module_eval rather than
        # define_method, because define_method is slower on dispatch.
        #
        # But sometimes the database might return columns with
        # characters that are not allowed in normal method names (like
        # 'my_column(omg)'. So to work around this we first define with
        # the __temp__ identifier, and then use alias method to rename
        # it to what we want.
        #
        # We are also defining a constant to hold the frozen string of
        # the attribute name. Using a constant means that we do not have
        # to allocate an object on each call to the attribute method.
        # Making it frozen means that it doesn't get duped when used to
        # key the @attributes in read_attribute.
        def self.define_attribute_accessor_method(owner, attr_name, writer: false)
          method_name = "#{attr_name}#{'=' if writer}"
          if attr_name.ascii_only? && DEF_SAFE_NAME.match?(attr_name)
            yield method_name, "'#{attr_name}'"
          else
            safe_name = attr_name.unpack1("h*")
            const_name = "ATTR_#{safe_name}"
            const_set(const_name, attr_name) unless const_defined?(const_name)
            temp_method_name = "__temp__#{safe_name}#{'=' if writer}"
            attr_name_expr = "::ActiveModel::AttributeMethods::AttrNames::#{const_name}"
            yield temp_method_name, attr_name_expr
          end
        end
      end
  end
end

attribute_methods_test.rb

# frozen_string_literal: true

require "cases/helper"

class ModelWithAttributes
  include ActiveModel::AttributeMethods

  class << self
    define_method(:bar) do
      "original bar"
    end
  end

  def attributes
    { foo: "value of foo", baz: "value of baz" }
  end

private
  def attribute(name)
    attributes[name.to_sym]
  end
end

class ModelWithAttributes2
  include ActiveModel::AttributeMethods

  attr_accessor :attributes

  attribute_method_suffix "_test", "_kw"

private
  def attribute(name)
    attributes[name.to_s]
  end

  def attribute_test(name, attrs = {})
    attrs[name] = attribute(name)
  end

  def attribute_kw(name, kw: 1)
    attribute(name)
  end

  def private_method
    "<3 <3"
  end

protected
  def protected_method
    "O_o O_o"
  end
end

class ModelWithAttributesWithSpaces
  include ActiveModel::AttributeMethods

  def attributes
    { 'foo bar': "value of foo bar" }
  end

private
  def attribute(name)
    attributes[name.to_sym]
  end
end

class ModelWithWeirdNamesAttributes
  include ActiveModel::AttributeMethods

  class << self
    define_method(:'c?d') do
      "original c?d"
    end
  end

  def attributes
    { 'a?b': "value of a?b" }
  end

private
  def attribute(name)
    attributes[name.to_sym]
  end
end

class ModelWithRubyKeywordNamedAttributes
  include ActiveModel::AttributeMethods

  def attributes
    { begin: "value of begin", end: "value of end" }
  end

private
  def attribute(name)
    attributes[name.to_sym]
  end
end

class ModelWithoutAttributesMethod
  include ActiveModel::AttributeMethods
end

class AttributeMethodsTest < ActiveModel::TestCase
  test "method missing works correctly even if attributes method is not defined" do
    assert_raises(NoMethodError) { ModelWithoutAttributesMethod.new.foo }
  end

  test "unrelated classes should not share attribute method matchers" do
    assert_not_equal ModelWithAttributes.public_send(:attribute_method_patterns),
                     ModelWithAttributes2.public_send(:attribute_method_patterns)
  end

  test "#define_attribute_method generates attribute method" do
    ModelWithAttributes.define_attribute_method(:foo)

    assert_respond_to ModelWithAttributes.new, :foo
    assert_equal "value of foo", ModelWithAttributes.new.foo
  ensure
    ModelWithAttributes.undefine_attribute_methods
  end

  test "#define_attribute_method does not generate attribute method if already defined in attribute module" do
    klass = Class.new(ModelWithAttributes)
    klass.send(:generated_attribute_methods).module_eval do
      def foo
        "<3"
      end
    end
    klass.define_attribute_method(:foo)

    assert_equal "<3", klass.new.foo
  end

  test "#define_attribute_method generates a method that is already defined on the host" do
    klass = Class.new(ModelWithAttributes) do
      def foo
        super
      end
    end
    klass.define_attribute_method(:foo)

    assert_equal "value of foo", klass.new.foo
  end

  test "#define_attribute_method generates attribute method with invalid identifier characters" do
    ModelWithWeirdNamesAttributes.define_attribute_method(:'a?b')

    assert_respond_to ModelWithWeirdNamesAttributes.new, :'a?b'
    assert_equal "value of a?b", ModelWithWeirdNamesAttributes.new.public_send("a?b")
  ensure
    ModelWithWeirdNamesAttributes.undefine_attribute_methods
  end

  test "#define_attribute_methods works passing multiple arguments" do
    ModelWithAttributes.define_attribute_methods(:foo, :baz)

    assert_equal "value of foo", ModelWithAttributes.new.foo
    assert_equal "value of baz", ModelWithAttributes.new.baz
  ensure
    ModelWithAttributes.undefine_attribute_methods
  end

  test "#define_attribute_methods generates attribute methods" do
    ModelWithAttributes.define_attribute_methods(:foo)

    assert_respond_to ModelWithAttributes.new, :foo
    assert_equal "value of foo", ModelWithAttributes.new.foo
  ensure
    ModelWithAttributes.undefine_attribute_methods
  end

  test "#alias_attribute generates attribute_aliases lookup hash" do
    klass = Class.new(ModelWithAttributes) do
      define_attribute_methods :foo
      alias_attribute :bar, :foo
    end

    assert_equal({ "bar" => "foo" }, klass.attribute_aliases)
  end

  test "#define_attribute_methods generates attribute methods with spaces in their names" do
    ModelWithAttributesWithSpaces.define_attribute_methods(:'foo bar')

    assert_respond_to ModelWithAttributesWithSpaces.new, :'foo bar'
    assert_equal "value of foo bar", ModelWithAttributesWithSpaces.new.public_send(:'foo bar')
  ensure
    ModelWithAttributesWithSpaces.undefine_attribute_methods
  end

  test "#alias_attribute works with attributes with spaces in their names" do
    ModelWithAttributesWithSpaces.define_attribute_methods(:'foo bar')
    ModelWithAttributesWithSpaces.alias_attribute(:'foo_bar', :'foo bar')

    assert_equal "value of foo bar", ModelWithAttributesWithSpaces.new.foo_bar
  ensure
    ModelWithAttributesWithSpaces.undefine_attribute_methods
  end

  test "#alias_attribute works with attributes named as a ruby keyword" do
    ModelWithRubyKeywordNamedAttributes.define_attribute_methods([:begin, :end])
    ModelWithRubyKeywordNamedAttributes.alias_attribute(:from, :begin)
    ModelWithRubyKeywordNamedAttributes.alias_attribute(:to, :end)

    assert_equal "value of begin", ModelWithRubyKeywordNamedAttributes.new.from
    assert_equal "value of end", ModelWithRubyKeywordNamedAttributes.new.to
  ensure
    ModelWithRubyKeywordNamedAttributes.undefine_attribute_methods
  end

  test "#undefine_attribute_methods removes attribute methods" do
    ModelWithAttributes.define_attribute_methods(:foo)
    ModelWithAttributes.undefine_attribute_methods

    assert_not_respond_to ModelWithAttributes.new, :foo
    assert_raises(NoMethodError) { ModelWithAttributes.new.foo }
  end

  test "accessing a suffixed attribute" do
    m = ModelWithAttributes2.new
    m.attributes = { "foo" => "bar" }
    attrs = {}

    assert_equal "bar", m.foo
    assert_equal "bar", m.foo_kw(kw: 2)
    assert_equal "bar", m.foo_test(attrs)
    assert_equal "bar", attrs["foo"]
  end

  test "defined attribute doesn't expand positional hash argument" do
    ModelWithAttributes2.define_attribute_methods(:foo)

    m = ModelWithAttributes2.new
    m.attributes = { "foo" => "bar" }
    attrs = {}

    assert_equal "bar", m.foo
    assert_equal "bar", m.foo_kw(kw: 2)
    assert_equal "bar", m.foo_test(attrs)
    assert_equal "bar", attrs["foo"]
  ensure
    ModelWithAttributes2.undefine_attribute_methods
  end

  test "should not interfere with method_missing if the attr has a private/protected method" do
    m = ModelWithAttributes2.new
    m.attributes = { "private_method" => "<3", "protected_method" => "O_o" }

    # dispatches to the *method*, not the attribute
    assert_equal "<3 <3",   m.send(:private_method)
    assert_equal "O_o O_o", m.send(:protected_method)

    # sees that a method is already defined, so doesn't intervene
    assert_raises(NoMethodError) { m.private_method }
    assert_raises(NoMethodError) { m.protected_method }
  end

  class ClassWithProtected
    protected
      def protected_method
      end
  end

  test "should not interfere with respond_to? if the attribute has a private/protected method" do
    m = ModelWithAttributes2.new
    m.attributes = { "private_method" => "<3", "protected_method" => "O_o" }

    assert_not_respond_to m, :private_method
    assert m.respond_to?(:private_method, true)

    c = ClassWithProtected.new

    # This is messed up, but it's how Ruby works at the moment. Apparently it will be changed
    # in the future.
    assert_equal c.respond_to?(:protected_method), m.respond_to?(:protected_method)
    assert m.respond_to?(:protected_method, true)
  end

  test "should use attribute_missing to dispatch a missing attribute" do
    m = ModelWithAttributes2.new
    m.attributes = { "foo" => "bar" }

    def m.attribute_missing(match, *args, &block)
      match
    end

    match = m.foo_test

    assert_equal "foo",            match.attr_name
    assert_equal "attribute_test", match.proxy_target
  end
end

attribute_mutation_tracker.rb

# frozen_string_literal: true

require "active_support/core_ext/hash/indifferent_access"
require "active_support/core_ext/object/duplicable"

module ActiveModel
  class AttributeMutationTracker # :nodoc:
    OPTION_NOT_GIVEN = Object.new

    def initialize(attributes)
      @attributes = attributes
    end

    def changed_attribute_names
      attr_names.select { |attr_name| changed?(attr_name) }
    end

    def changed_values
      attr_names.each_with_object({}.with_indifferent_access) do |attr_name, result|
        if changed?(attr_name)
          result[attr_name] = original_value(attr_name)
        end
      end
    end

    def changes
      attr_names.each_with_object({}.with_indifferent_access) do |attr_name, result|
        if change = change_to_attribute(attr_name)
          result.merge!(attr_name => change)
        end
      end
    end

    def change_to_attribute(attr_name)
      if changed?(attr_name)
        [original_value(attr_name), fetch_value(attr_name)]
      end
    end

    def any_changes?
      attr_names.any? { |attr| changed?(attr) }
    end

    def changed?(attr_name, from: OPTION_NOT_GIVEN, to: OPTION_NOT_GIVEN)
      attribute_changed?(attr_name) &&
        (OPTION_NOT_GIVEN == from || original_value(attr_name) == from) &&
        (OPTION_NOT_GIVEN == to || fetch_value(attr_name) == to)
    end

    def changed_in_place?(attr_name)
      attributes[attr_name].changed_in_place?
    end

    def forget_change(attr_name)
      attributes[attr_name] = attributes[attr_name].forgetting_assignment
      forced_changes.delete(attr_name)
    end

    def original_value(attr_name)
      attributes[attr_name].original_value
    end

    def force_change(attr_name)
      forced_changes[attr_name] = fetch_value(attr_name)
    end

    private
      attr_reader :attributes

      def forced_changes
        @forced_changes ||= {}
      end

      def attr_names
        attributes.keys
      end

      def attribute_changed?(attr_name)
        forced_changes.include?(attr_name) || !!attributes[attr_name].changed?
      end

      def fetch_value(attr_name)
        attributes.fetch_value(attr_name)
      end
  end

  class ForcedMutationTracker < AttributeMutationTracker # :nodoc:
    def initialize(attributes)
      super
      @finalized_changes = nil
    end

    def changed_in_place?(attr_name)
      false
    end

    def change_to_attribute(attr_name)
      if finalized_changes&.include?(attr_name)
        finalized_changes[attr_name].dup
      else
        super
      end
    end

    def forget_change(attr_name)
      forced_changes.delete(attr_name)
    end

    def original_value(attr_name)
      if changed?(attr_name)
        forced_changes[attr_name]
      else
        fetch_value(attr_name)
      end
    end

    def force_change(attr_name)
      forced_changes[attr_name] = clone_value(attr_name) unless attribute_changed?(attr_name)
    end

    def finalize_changes
      @finalized_changes = changes
    end

    private
      attr_reader :finalized_changes

      def attr_names
        forced_changes.keys
      end

      def attribute_changed?(attr_name)
        forced_changes.include?(attr_name)
      end

      def fetch_value(attr_name)
        attributes.send(:_read_attribute, attr_name)
      end

      def clone_value(attr_name)
        value = fetch_value(attr_name)
        value.duplicable? ? value.clone : value
      rescue TypeError, NoMethodError
        value
      end
  end

  class NullMutationTracker # :nodoc:
    include Singleton

    def changed_attribute_names
      []
    end

    def changed_values
      {}
    end

    def changes
      {}
    end

    def change_to_attribute(attr_name)
    end

    def any_changes?
      false
    end

    def changed?(attr_name, **)
      false
    end

    def changed_in_place?(attr_name)
      false
    end

    def original_value(attr_name)
    end
  end
end

attribute_set.rb

# frozen_string_literal: true

require "active_support/core_ext/enumerable"
require "active_support/core_ext/object/deep_dup"
require "active_model/attribute_set/builder"
require "active_model/attribute_set/yaml_encoder"

module ActiveModel
  class AttributeSet # :nodoc:
    delegate :each_value, :fetch, :except, to: :attributes

    def initialize(attributes)
      @attributes = attributes
    end

    def [](name)
      @attributes[name] || default_attribute(name)
    end

    def []=(name, value)
      @attributes[name] = value
    end

    def values_before_type_cast
      attributes.transform_values(&:value_before_type_cast)
    end

    def values_for_database
      attributes.transform_values(&:value_for_database)
    end

    def to_hash
      keys.index_with { |name| self[name].value }
    end
    alias :to_h :to_hash

    def key?(name)
      attributes.key?(name) && self[name].initialized?
    end

    def keys
      attributes.each_key.select { |name| self[name].initialized? }
    end

    def fetch_value(name, &block)
      self[name].value(&block)
    end

    def write_from_database(name, value)
      @attributes[name] = self[name].with_value_from_database(value)
    end

    def write_from_user(name, value)
      raise FrozenError, "can't modify frozen attributes" if frozen?
      @attributes[name] = self[name].with_value_from_user(value)
      value
    end

    def write_cast_value(name, value)
      @attributes[name] = self[name].with_cast_value(value)
    end

    def freeze
      attributes.freeze
      super
    end

    def deep_dup
      AttributeSet.new(attributes.deep_dup)
    end

    def initialize_dup(_)
      @attributes = @attributes.dup
      super
    end

    def initialize_clone(_)
      @attributes = @attributes.clone
      super
    end

    def reset(key)
      if key?(key)
        write_from_database(key, nil)
      end
    end

    def accessed
      attributes.each_key.select { |name| self[name].has_been_read? }
    end

    def map(&block)
      new_attributes = attributes.transform_values(&block)
      AttributeSet.new(new_attributes)
    end

    def ==(other)
      attributes == other.attributes
    end

    protected
      attr_reader :attributes

    private
      def default_attribute(name)
        Attribute.null(name)
      end
  end
end

attribute_set_test.rb

# frozen_string_literal: true

require "cases/helper"
require "active_model/attribute_set"

module ActiveModel
  class AttributeSetTest < ActiveModel::TestCase
    test "building a new set from raw attributes" do
      builder = AttributeSet::Builder.new(foo: Type::Integer.new, bar: Type::Float.new)
      attributes = builder.build_from_database(foo: "1.1", bar: "2.2")

      assert_equal 1, attributes[:foo].value
      assert_equal 2.2, attributes[:bar].value
      assert_equal :foo, attributes[:foo].name
      assert_equal :bar, attributes[:bar].name
    end

    test "building with custom types" do
      builder = AttributeSet::Builder.new(foo: Type::Float.new)
      attributes = builder.build_from_database({ foo: "3.3", bar: "4.4" }, { bar: Type::Integer.new })

      assert_equal 3.3, attributes[:foo].value
      assert_equal 4, attributes[:bar].value
    end

    test "[] returns a null object" do
      builder = AttributeSet::Builder.new(foo: Type::Float.new)
      attributes = builder.build_from_database(foo: "3.3")

      assert_equal "3.3", attributes[:foo].value_before_type_cast
      assert_nil attributes[:bar].value_before_type_cast
      assert_equal :bar, attributes[:bar].name
    end

    test "duping creates a new hash, but does not dup the attributes" do
      builder = AttributeSet::Builder.new(foo: Type::Integer.new, bar: Type::String.new)
      attributes = builder.build_from_database(foo: 1, bar: "foo")

      # Ensure the type cast value is cached
      attributes[:foo].value
      attributes[:bar].value

      duped = attributes.dup
      duped.write_from_database(:foo, 2)
      duped[:bar].value << "bar"

      assert_equal 1, attributes[:foo].value
      assert_equal 2, duped[:foo].value
      assert_equal "foobar", attributes[:bar].value
      assert_equal "foobar", duped[:bar].value
    end

    test "deep_duping creates a new hash and dups each attribute" do
      builder = AttributeSet::Builder.new(foo: Type::Integer.new, bar: Type::String.new)
      attributes = builder.build_from_database(foo: 1, bar: "foo")

      # Ensure the type cast value is cached
      attributes[:foo].value
      attributes[:bar].value

      duped = attributes.deep_dup
      duped.write_from_database(:foo, 2)
      duped[:bar].value << "bar"

      assert_equal 1, attributes[:foo].value
      assert_equal 2, duped[:foo].value
      assert_equal "foo", attributes[:bar].value
      assert_equal "foobar", duped[:bar].value
    end

    test "freezing cloned set does not freeze original" do
      attributes = AttributeSet.new({})
      clone = attributes.clone

      clone.freeze

      assert_predicate clone, :frozen?
      assert_not_predicate attributes, :frozen?
    end

    test "to_hash returns a hash of the type cast values" do
      builder = AttributeSet::Builder.new(foo: Type::Integer.new, bar: Type::Float.new)
      attributes = builder.build_from_database(foo: "1.1", bar: "2.2")

      assert_equal({ foo: 1, bar: 2.2 }, attributes.to_hash)
      assert_equal({ foo: 1, bar: 2.2 }, attributes.to_h)
    end

    test "to_hash maintains order" do
      builder = AttributeSet::Builder.new(foo: Type::Integer.new, bar: Type::Float.new)
      attributes = builder.build_from_database(foo: "2.2", bar: "3.3")

      attributes[:bar]
      hash = attributes.to_h

      assert_equal [[:foo, 2], [:bar, 3.3]], hash.to_a
    end

    test "values_before_type_cast" do
      builder = AttributeSet::Builder.new(foo: Type::Integer.new, bar: Type::Integer.new)
      attributes = builder.build_from_database(foo: "1.1", bar: "2.2")

      assert_equal({ foo: "1.1", bar: "2.2" }, attributes.values_before_type_cast)
    end

    test "known columns are built with uninitialized attributes" do
      attributes = attributes_with_uninitialized_key
      assert_predicate attributes[:foo], :initialized?
      assert_not_predicate attributes[:bar], :initialized?
    end

    test "uninitialized attributes are not included in the attributes hash" do
      attributes = attributes_with_uninitialized_key
      assert_equal({ foo: 1 }, attributes.to_hash)
    end

    test "uninitialized attributes are not included in keys" do
      attributes = attributes_with_uninitialized_key
      assert_equal [:foo], attributes.keys
    end

    test "uninitialized attributes return false for key?" do
      attributes = attributes_with_uninitialized_key
      assert attributes.key?(:foo)
      assert_not attributes.key?(:bar)
    end

    test "unknown attributes return false for key?" do
      attributes = attributes_with_uninitialized_key
      assert_not attributes.key?(:wibble)
    end

    test "fetch_value returns the value for the given initialized attribute" do
      builder = AttributeSet::Builder.new(foo: Type::Integer.new, bar: Type::Float.new)
      attributes = builder.build_from_database(foo: "1.1", bar: "2.2")

      assert_equal 1, attributes.fetch_value(:foo)
      assert_equal 2.2, attributes.fetch_value(:bar)
    end

    test "fetch_value returns nil for unknown attributes" do
      attributes = attributes_with_uninitialized_key
      assert_nil attributes.fetch_value(:wibble) { "hello" }
    end

    test "fetch_value returns nil for unknown attributes when types has a default" do
      types = Hash.new(Type::Value.new)
      builder = AttributeSet::Builder.new(types)
      attributes = builder.build_from_database

      assert_nil attributes.fetch_value(:wibble) { "hello" }
    end

    test "fetch_value uses the given block for uninitialized attributes" do
      attributes = attributes_with_uninitialized_key
      value = attributes.fetch_value(:bar) { |n| n.to_s + "!" }
      assert_equal "bar!", value
    end

    test "fetch_value returns nil for uninitialized attributes if no block is given" do
      attributes = attributes_with_uninitialized_key
      assert_nil attributes.fetch_value(:bar)
    end

    test "the primary_key is always initialized" do
      defaults = { foo: Attribute.from_user(:foo, nil, nil) }
      builder = AttributeSet::Builder.new({ foo: Type::Integer.new }, defaults)
      attributes = builder.build_from_database

      assert attributes.key?(:foo)
      assert_equal [:foo], attributes.keys
      assert_predicate attributes[:foo], :initialized?
    end

    class MyType
      def cast(value)
        return if value.nil?
        value + " from user"
      end

      def deserialize(value)
        return if value.nil?
        value + " from database"
      end

      def assert_valid_value(*)
      end
    end

    test "write_from_database sets the attribute with database typecasting" do
      builder = AttributeSet::Builder.new(foo: MyType.new)
      attributes = builder.build_from_database

      assert_nil attributes.fetch_value(:foo)

      attributes.write_from_database(:foo, "value")

      assert_equal "value from database", attributes.fetch_value(:foo)
    end

    test "write_from_user sets the attribute with user typecasting" do
      builder = AttributeSet::Builder.new(foo: MyType.new)
      attributes = builder.build_from_database

      assert_nil attributes.fetch_value(:foo)

      attributes.write_from_user(:foo, "value")

      assert_equal "value from user", attributes.fetch_value(:foo)
    end

    class MySerializedType < ::ActiveModel::Type::Value
      def serialize(value)
        value + " serialized"
      end
    end

    test "values_for_database" do
      builder = AttributeSet::Builder.new(foo: MySerializedType.new)
      attributes = builder.build_from_database

      attributes.write_from_user(:foo, "value")

      assert_equal({ foo: "value serialized" }, attributes.values_for_database)
    end

    test "freezing doesn't prevent the set from materializing" do
      builder = AttributeSet::Builder.new(foo: Type::String.new)
      attributes = builder.build_from_database(foo: "1")

      attributes.freeze
      assert_equal({ foo: "1" }, attributes.to_hash)
    end

    test "marshalling dump/load materialized attribute hash" do
      builder = AttributeSet::Builder.new(foo: Type::String.new)

      def builder.build_from_database(values = {}, additional_types = {})
        attributes = LazyAttributeHash.new(types, values, additional_types, default_attributes)
        AttributeSet.new(attributes)
      end

      attributes = builder.build_from_database(foo: "1")

      data = Marshal.dump(attributes)
      attributes = Marshal.load(data)
      assert_equal({ foo: "1" }, attributes.to_hash)
    end

    test "#accessed_attributes returns only attributes which have been read" do
      builder = AttributeSet::Builder.new(foo: Type::Value.new, bar: Type::Value.new)
      attributes = builder.build_from_database(foo: "1", bar: "2")

      assert_equal [], attributes.accessed

      attributes.fetch_value(:foo)

      assert_equal [:foo], attributes.accessed
    end

    test "#map returns a new attribute set with the changes applied" do
      builder = AttributeSet::Builder.new(foo: Type::Integer.new, bar: Type::Integer.new)
      attributes = builder.build_from_database(foo: "1", bar: "2")
      new_attributes = attributes.map do |attr|
        attr.with_cast_value(attr.value + 1)
      end

      assert_equal 2, new_attributes.fetch_value(:foo)
      assert_equal 3, new_attributes.fetch_value(:bar)
    end

    test "comparison for equality is correctly implemented" do
      builder = AttributeSet::Builder.new(foo: Type::Integer.new, bar: Type::Integer.new)
      attributes = builder.build_from_database(foo: "1", bar: "2")
      attributes2 = builder.build_from_database(foo: "1", bar: "2")
      attributes3 = builder.build_from_database(foo: "2", bar: "2")

      assert_equal attributes, attributes2
      assert_not_equal attributes2, attributes3
    end

    private
      def attributes_with_uninitialized_key
        builder = AttributeSet::Builder.new(foo: Type::Integer.new, bar: Type::Float.new)
        builder.build_from_database(foo: "1.1")
      end
  end
end

attribute_test.rb

# frozen_string_literal: true

require "cases/helper"

module ActiveModel
  class AttributeTest < ActiveModel::TestCase
    setup do
      @type = Minitest::Mock.new
    end

    teardown do
      assert @type.verify
    end

    test "from_database + read type casts from database" do
      @type.expect(:deserialize, "type cast from database", ["a value"])
      attribute = Attribute.from_database(nil, "a value", @type)

      type_cast_value = attribute.value

      assert_equal "type cast from database", type_cast_value
    end

    test "from_user + read type casts from user" do
      @type.expect(:cast, "type cast from user", ["a value"])
      attribute = Attribute.from_user(nil, "a value", @type)

      type_cast_value = attribute.value

      assert_equal "type cast from user", type_cast_value
    end

    test "reading memoizes the value" do
      @type.expect(:deserialize, "from the database", ["whatever"])
      attribute = Attribute.from_database(nil, "whatever", @type)

      type_cast_value = attribute.value
      second_read = attribute.value

      assert_equal "from the database", type_cast_value
      assert_same type_cast_value, second_read
    end

    test "reading memoizes falsy values" do
      @type.expect(:deserialize, false, ["whatever"])
      attribute = Attribute.from_database(nil, "whatever", @type)

      attribute.value
      attribute.value
    end

    test "read_before_typecast returns the given value" do
      attribute = Attribute.from_database(nil, "raw value", @type)

      raw_value = attribute.value_before_type_cast

      assert_equal "raw value", raw_value
    end

    test "from_database + read_for_database type casts to and from database" do
      @type.expect(:deserialize, "read from database", ["whatever"])
      @type.expect(:serialize, "ready for database", ["read from database"])
      attribute = Attribute.from_database(nil, "whatever", @type)

      serialize = attribute.value_for_database

      assert_equal "ready for database", serialize
    end

    test "from_user + read_for_database type casts from the user to the database" do
      @type.expect(:cast, "read from user", ["whatever"])
      @type.expect(:serialize, "ready for database", ["read from user"])
      attribute = Attribute.from_user(nil, "whatever", @type)

      serialize = attribute.value_for_database

      assert_equal "ready for database", serialize
    end

    test "duping dups the value" do
      @type.expect(:deserialize, +"type cast", ["a value"])
      attribute = Attribute.from_database(nil, "a value", @type)

      value_from_orig = attribute.value
      value_from_clone = attribute.dup.value
      value_from_orig << " foo"

      assert_equal "type cast foo", value_from_orig
      assert_equal "type cast", value_from_clone
    end

    test "duping does not dup the value if it is not dupable" do
      @type.expect(:deserialize, false, ["a value"])
      attribute = Attribute.from_database(nil, "a value", @type)

      assert_same attribute.value, attribute.dup.value
    end

    test "duping does not eagerly type cast if we have not yet type cast" do
      attribute = Attribute.from_database(nil, "a value", @type)
      attribute.dup
    end

    class MyType
      def cast(value)
        value + " from user"
      end

      def deserialize(value)
        value + " from database"
      end

      def assert_valid_value(*)
      end
    end

    test "with_value_from_user returns a new attribute with the value from the user" do
      old = Attribute.from_database(nil, "old", MyType.new)
      new = old.with_value_from_user("new")

      assert_equal "old from database", old.value
      assert_equal "new from user", new.value
    end

    test "with_value_from_database returns a new attribute with the value from the database" do
      old = Attribute.from_user(nil, "old", MyType.new)
      new = old.with_value_from_database("new")

      assert_equal "old from user", old.value
      assert_equal "new from database", new.value
    end

    test "uninitialized attributes yield their name if a block is given to value" do
      block = proc { |name| name.to_s + "!" }
      foo = Attribute.uninitialized(:foo, nil)
      bar = Attribute.uninitialized(:bar, nil)

      assert_equal "foo!", foo.value(&block)
      assert_equal "bar!", bar.value(&block)
    end

    test "uninitialized attributes have no value" do
      assert_nil Attribute.uninitialized(:foo, nil).value
    end

    test "attributes equal other attributes with the same constructor arguments" do
      first = Attribute.from_database(:foo, 1, Type::Integer.new)
      second = Attribute.from_database(:foo, 1, Type::Integer.new)
      assert_equal first, second
    end

    test "attributes do not equal attributes with different names" do
      first = Attribute.from_database(:foo, 1, Type::Integer.new)
      second = Attribute.from_database(:bar, 1, Type::Integer.new)
      assert_not_equal first, second
    end

    test "attributes do not equal attributes with different types" do
      first = Attribute.from_database(:foo, 1, Type::Integer.new)
      second = Attribute.from_database(:foo, 1, Type::Float.new)
      assert_not_equal first, second
    end

    test "attributes do not equal attributes with different values" do
      first = Attribute.from_database(:foo, 1, Type::Integer.new)
      second = Attribute.from_database(:foo, 2, Type::Integer.new)
      assert_not_equal first, second
    end

    test "attributes do not equal attributes of other classes" do
      first = Attribute.from_database(:foo, 1, Type::Integer.new)
      second = Attribute.from_user(:foo, 1, Type::Integer.new)
      assert_not_equal first, second
    end

    test "an attribute has not been read by default" do
      attribute = Attribute.from_database(:foo, 1, Type::Value.new)
      assert_not_predicate attribute, :has_been_read?
    end

    test "an attribute has been read when its value is calculated" do
      attribute = Attribute.from_database(:foo, 1, Type::Value.new)
      attribute.value
      assert_predicate attribute, :has_been_read?
    end

    test "an attribute is not changed if it hasn't been assigned or mutated" do
      attribute = Attribute.from_database(:foo, 1, Type::Value.new)

      assert_not_predicate attribute, :changed?
    end

    test "an attribute is changed if it's been assigned a new value" do
      attribute = Attribute.from_database(:foo, 1, Type::Value.new)
      changed = attribute.with_value_from_user(2)

      assert_predicate changed, :changed?
    end

    test "an attribute is not changed if it's assigned the same value" do
      attribute = Attribute.from_database(:foo, 1, Type::Value.new)
      unchanged = attribute.with_value_from_user(1)

      assert_not_predicate unchanged, :changed?
    end

    test "an attribute cannot be mutated if it has not been read,
      and skips expensive calculations" do
      type_which_raises_from_all_methods = Object.new
      attribute = Attribute.from_database(:foo, "bar", type_which_raises_from_all_methods)

      assert_not_predicate attribute, :changed_in_place?
    end

    test "an attribute is changed if it has been mutated" do
      attribute = Attribute.from_database(:foo, "bar", Type::String.new)
      attribute.value << "!"

      assert_predicate attribute, :changed_in_place?
      assert_predicate attribute, :changed?
    end

    test "an attribute can forget its changes" do
      attribute = Attribute.from_database(:foo, "bar", Type::String.new)
      changed = attribute.with_value_from_user("foo")
      forgotten = changed.forgetting_assignment

      assert changed.changed? # Check to avoid a false positive
      assert_not_predicate forgotten, :changed?
    end

    test "with_value_from_user validates the value" do
      type = Type::Value.new
      type.define_singleton_method(:assert_valid_value) do |value|
        if value == 1
          raise ArgumentError
        end
      end

      attribute = Attribute.from_database(:foo, 1, type)
      assert_equal 1, attribute.value
      assert_equal 2, attribute.with_value_from_user(2).value
      assert_raises ArgumentError do
        attribute.with_value_from_user(1)
      end
    end

    test "with_type preserves mutations" do
      attribute = Attribute.from_database(:foo, +"", Type::Value.new)
      attribute.value << "1"

      assert_equal 1, attribute.with_type(Type::Integer.new).value
    end
  end
end

attributes.rb

# frozen_string_literal: true

require "active_model/attribute_set"
require "active_model/attribute/user_provided_default"

module ActiveModel
  # The Attributes module allows models to define attributes beyond simple Ruby
  # readers and writers. Similar to Active Record attributes, which are
  # typically inferred from the database schema, Active Model Attributes are
  # aware of data types, can have default values, and can handle casting and
  # serialization.
  #
  # To use Attributes, include the module in your model class and define your
  # attributes using the +attribute+ macro. It accepts a name, a type, a default
  # value, and any other options supported by the attribute type.
  #
  # ==== Examples
  #
  #   class Person
  #     include ActiveModel::Attributes
  #
  #     attribute :name, :string
  #     attribute :active, :boolean, default: true
  #   end
  #
  #   person = Person.new
  #   person.name = "Volmer"
  #
  #   person.name # => "Volmer"
  #   person.active # => true
  module Attributes
    extend ActiveSupport::Concern
    include ActiveModel::AttributeMethods

    included do
      attribute_method_suffix "=", parameters: "value"
      class_attribute :attribute_types, :_default_attributes, instance_accessor: false
      self.attribute_types = Hash.new(Type.default_value)
      self._default_attributes = AttributeSet.new({})
    end

    module ClassMethods
      # Defines a model attribute. In addition to the attribute name, a cast
      # type and default value may be specified, as well as any options
      # supported by the given cast type.
      #
      #   class Person
      #     include ActiveModel::Attributes
      #
      #     attribute :name, :string
      #     attribute :active, :boolean, default: true
      #   end
      #
      #   person = Person.new
      #   person.name = "Volmer"
      #
      #   person.name   # => "Volmer"
      #   person.active # => true
      def attribute(name, cast_type = nil, default: NO_DEFAULT_PROVIDED, **options)
        name = name.to_s

        cast_type = Type.lookup(cast_type, **options) if Symbol === cast_type
        cast_type ||= attribute_types[name]

        self.attribute_types = attribute_types.merge(name => cast_type)
        define_default_attribute(name, default, cast_type)
        define_attribute_method(name)
      end

      # Returns an array of attribute names as strings.
      #
      #   class Person
      #     include ActiveModel::Attributes
      #
      #     attribute :name, :string
      #     attribute :age, :integer
      #   end
      #
      #   Person.attribute_names # => ["name", "age"]
      def attribute_names
        attribute_types.keys
      end

      private
        def define_method_attribute=(name, owner:)
          ActiveModel::AttributeMethods::AttrNames.define_attribute_accessor_method(
            owner, name, writer: true,
          ) do |temp_method_name, attr_name_expr|
            owner.define_cached_method("#{name}=", as: temp_method_name, namespace: :active_model) do |batch|
              batch <<
                "def #{temp_method_name}(value)" <<
                "  _write_attribute(#{attr_name_expr}, value)" <<
                "end"
            end
          end
        end

        NO_DEFAULT_PROVIDED = Object.new # :nodoc:
        private_constant :NO_DEFAULT_PROVIDED

        def define_default_attribute(name, value, type)
          self._default_attributes = _default_attributes.deep_dup
          if value == NO_DEFAULT_PROVIDED
            default_attribute = _default_attributes[name].with_type(type)
          else
            default_attribute = Attribute::UserProvidedDefault.new(
              name,
              value,
              type,
              _default_attributes.fetch(name.to_s) { nil },
            )
          end
          _default_attributes[name] = default_attribute
        end
    end

    def initialize(*) # :nodoc:
      @attributes = self.class._default_attributes.deep_dup
      super
    end

    def initialize_dup(other) # :nodoc:
      @attributes = @attributes.deep_dup
      super
    end

    # Returns a hash of all the attributes with their names as keys and the
    # values of the attributes as values.
    #
    #   class Person
    #     include ActiveModel::Attributes
    #
    #     attribute :name, :string
    #     attribute :age, :integer
    #   end
    #
    #   person = Person.new
    #   person.name = "Francesco"
    #   person.age = 22
    #
    #   person.attributes # => { "name" => "Francesco", "age" => 22}
    def attributes
      @attributes.to_hash
    end

    # Returns an array of attribute names as strings.
    #
    #   class Person
    #     include ActiveModel::Attributes
    #
    #     attribute :name, :string
    #     attribute :age, :integer
    #   end
    #
    #   person = Person.new
    #   person.attribute_names # => ["name", "age"]
    def attribute_names
      @attributes.keys
    end

    def freeze # :nodoc:
      @attributes = @attributes.clone.freeze unless frozen?
      super
    end

    private
      def _write_attribute(attr_name, value)
        @attributes.write_from_user(attr_name, value)
      end
      alias :attribute= :_write_attribute

      def attribute(attr_name)
        @attributes.fetch_value(attr_name)
      end
  end
end

attributes_dirty_test.rb

# frozen_string_literal: true

require "cases/helper"

class AttributesDirtyTest < ActiveModel::TestCase
  class DirtyModel
    include ActiveModel::Model
    include ActiveModel::Attributes
    include ActiveModel::Dirty
    attribute :name, :string
    attribute :color, :string
    attribute :size, :integer

    def save
      changes_applied
    end
  end

  setup do
    @model = DirtyModel.new
  end

  test "setting attribute will result in change" do
    assert_not_predicate @model, :changed?
    assert_not_predicate @model, :name_changed?
    @model.name = "Ringo"
    assert_predicate @model, :changed?
    assert_predicate @model, :name_changed?
  end

  test "list of changed attribute keys" do
    assert_equal [], @model.changed
    @model.name = "Paul"
    assert_equal ["name"], @model.changed
  end

  test "changes to attribute values" do
    assert_not @model.changes["name"]
    @model.name = "John"
    assert_equal [nil, "John"], @model.changes["name"]
  end

  test "checking if an attribute has changed to a particular value" do
    @model.name = "Ringo"
    assert @model.name_changed?(from: nil, to: "Ringo")
    assert_not @model.name_changed?(from: "Pete", to: "Ringo")
    assert @model.name_changed?(to: "Ringo")
    assert_not @model.name_changed?(to: "Pete")
    assert @model.name_changed?(from: nil)
    assert_not @model.name_changed?(from: "Pete")
  end

  test "changes accessible through both strings and symbols" do
    @model.name = "David"
    assert_not_nil @model.changes[:name]
    assert_not_nil @model.changes["name"]
  end

  test "be consistent with symbols arguments after the changes are applied" do
    @model.name = "David"
    assert @model.attribute_changed?(:name)
    @model.save
    @model.name = "Rafael"
    assert @model.attribute_changed?(:name)
  end

  test "attribute mutation" do
    @model.name = "Yam"
    @model.save
    assert_not_predicate @model, :name_changed?
    @model.name.replace("Hadad")
    assert_predicate @model, :name_changed?
  end

  test "resetting attribute" do
    @model.name = "Bob"
    @model.restore_name!
    assert_nil @model.name
    assert_not_predicate @model, :name_changed?
  end

  test "setting color to same value should not result in change being recorded" do
    @model.color = "red"
    assert_predicate @model, :color_changed?
    @model.save
    assert_not_predicate @model, :color_changed?
    assert_not_predicate @model, :changed?
    @model.color = "red"
    assert_not_predicate @model, :color_changed?
    assert_not_predicate @model, :changed?
  end

  test "saving should reset model's changed status" do
    @model.name = "Alf"
    assert_predicate @model, :changed?
    @model.save
    assert_not_predicate @model, :changed?
    assert_not_predicate @model, :name_changed?
  end

  test "saving should preserve previous changes" do
    @model.name = "Jericho Cane"
    @model.save
    assert_equal [nil, "Jericho Cane"], @model.previous_changes["name"]
  end

  test "setting new attributes should not affect previous changes" do
    @model.name = "Jericho Cane"
    @model.save
    @model.name = "DudeFella ManGuy"
    assert_equal [nil, "Jericho Cane"], @model.name_previous_change
  end

  test "saving should preserve model's previous changed status" do
    @model.name = "Jericho Cane"
    @model.save
    assert_predicate @model, :name_previously_changed?
  end

  test "previous value is preserved when changed after save" do
    assert_equal({}, @model.changed_attributes)
    @model.name = "Paul"
    assert_equal({ "name" => nil }, @model.changed_attributes)

    @model.save

    @model.name = "John"
    assert_equal({ "name" => "Paul" }, @model.changed_attributes)
  end

  test "changing the same attribute multiple times retains the correct original value" do
    @model.name = "Otto"
    @model.save
    @model.name = "DudeFella ManGuy"
    @model.name = "Mr. Manfredgensonton"
    assert_equal ["Otto", "Mr. Manfredgensonton"], @model.name_change
    assert_equal @model.name_was, "Otto"
  end

  test "using attribute_will_change! with a symbol" do
    @model.size = 1
    assert_predicate @model, :size_changed?
  end

  test "clear_changes_information should reset all changes" do
    @model.name = "Dmitry"
    @model.name_changed?
    @model.save
    @model.name = "Bob"

    assert_equal [nil, "Dmitry"], @model.previous_changes["name"]
    assert_equal "Dmitry", @model.changed_attributes["name"]

    @model.clear_changes_information

    assert_equal ActiveSupport::HashWithIndifferentAccess.new, @model.previous_changes
    assert_equal ActiveSupport::HashWithIndifferentAccess.new, @model.changed_attributes
  end

  test "restore_attributes should restore all previous data" do
    @model.name = "Dmitry"
    @model.color = "Red"
    @model.save
    @model.name = "Bob"
    @model.color = "White"

    @model.restore_attributes

    assert_not_predicate @model, :changed?
    assert_equal "Dmitry", @model.name
    assert_equal "Red", @model.color
  end

  test "restore_attributes can restore only some attributes" do
    @model.name = "Dmitry"
    @model.color = "Red"
    @model.save
    @model.name = "Bob"
    @model.color = "White"

    @model.restore_attributes(["name"])

    assert_predicate @model, :changed?
    assert_equal "Dmitry", @model.name
    assert_equal "White", @model.color
  end

  test "changing the attribute reports a change only when the cast value changes" do
    @model.size = "2.3"
    @model.save
    @model.size = "2.1"

    assert_equal false, @model.changed?

    @model.size = "5.1"

    assert_equal true, @model.changed?
    assert_equal true, @model.size_changed?
    assert_equal({ "size" => [2, 5] }, @model.changes)
  end
end

attributes_test.rb

# frozen_string_literal: true

require "cases/helper"

module ActiveModel
  class AttributesTest < ActiveModel::TestCase
    class ModelForAttributesTest
      include ActiveModel::Model
      include ActiveModel::Attributes

      attribute :integer_field, :integer
      attribute :string_field, :string
      attribute :decimal_field, :decimal
      attribute :string_with_default, :string, default: "default string"
      attribute :date_field, :date, default: -> { Date.new(2016, 1, 1) }
      attribute :boolean_field, :boolean
    end

    class ChildModelForAttributesTest < ModelForAttributesTest
    end

    class GrandchildModelForAttributesTest < ChildModelForAttributesTest
      attribute :integer_field, :string
      attribute :string_field, default: "default string"
    end

    class ModelWithGeneratedAttributeMethods
      include ActiveModel::Attributes

      attribute :foo
    end

    class ModelWithProxiedAttributeMethods
      include ActiveModel::AttributeMethods

      attribute_method_suffix "="

      define_attribute_method(:foo)

      def attribute=(_, _)
      end
    end

    test "models that proxy attributes do not conflict with models with generated methods" do
      ModelWithGeneratedAttributeMethods.new

      model = ModelWithProxiedAttributeMethods.new

      assert_nothing_raised do
        model.foo = "foo"
      end
    end

    test "properties assignment" do
      data = ModelForAttributesTest.new(
        integer_field: "2.3",
        string_field: "Rails FTW",
        decimal_field: "12.3",
        boolean_field: "0"
      )

      assert_equal 2, data.integer_field
      assert_equal "Rails FTW", data.string_field
      assert_equal BigDecimal("12.3"), data.decimal_field
      assert_equal "default string", data.string_with_default
      assert_equal Date.new(2016, 1, 1), data.date_field
      assert_equal false, data.boolean_field

      data.integer_field = 10
      data.string_with_default = nil
      data.boolean_field = "1"

      assert_equal 10, data.integer_field
      assert_nil data.string_with_default
      assert_equal true, data.boolean_field
    end

    test "reading attributes" do
      data = ModelForAttributesTest.new(
        integer_field: 1.1,
        string_field: 1.1,
        decimal_field: 1.1,
        boolean_field: 1.1
      )

      expected_attributes = {
        integer_field: 1,
        string_field: "1.1",
        decimal_field: BigDecimal("1.1"),
        string_with_default: "default string",
        date_field: Date.new(2016, 1, 1),
        boolean_field: true
      }.stringify_keys

      assert_equal expected_attributes, data.attributes
    end

    test "reading attribute names" do
      names = [
        "integer_field",
        "string_field",
        "decimal_field",
        "string_with_default",
        "date_field",
        "boolean_field"
      ]

      assert_equal names, ModelForAttributesTest.attribute_names
      assert_equal names, ModelForAttributesTest.new.attribute_names
    end

    test "nonexistent attribute" do
      assert_raise ActiveModel::UnknownAttributeError do
        ModelForAttributesTest.new(nonexistent: "nonexistent")
      end
    end

    test "children inherit attributes" do
      data = ChildModelForAttributesTest.new(integer_field: "4.4")

      assert_equal 4, data.integer_field
    end

    test "children can override parents" do
      klass = GrandchildModelForAttributesTest

      assert_instance_of Type::String, klass.attribute_types["integer_field"]
      assert_instance_of Type::String, klass.attribute_types["string_field"]

      data = GrandchildModelForAttributesTest.new(integer_field: "4.4")

      assert_equal "4.4", data.integer_field
      assert_equal "default string", data.string_field
    end

    test "attributes with proc defaults can be marshalled" do
      data = ModelForAttributesTest.new
      attributes = data.instance_variable_get(:@attributes)
      round_tripped = Marshal.load(Marshal.dump(data))
      new_attributes = round_tripped.instance_variable_get(:@attributes)

      assert_equal attributes, new_attributes
    end

    test "attributes can be dup-ed" do
      data = ModelForAttributesTest.new
      data.integer_field = 1

      duped = data.dup

      assert_equal 1, data.integer_field
      assert_equal 1, duped.integer_field

      duped.integer_field = 2

      assert_equal 1, data.integer_field
      assert_equal 2, duped.integer_field
    end

    test "can't modify attributes if frozen" do
      data = ModelForAttributesTest.new
      data.freeze
      assert data.frozen?
      assert_raise(FrozenError) { data.integer_field = 1 }
    end

    test "attributes can be frozen again" do
      data = ModelForAttributesTest.new
      data.freeze
      assert_nothing_raised { data.freeze }
    end

    test "unknown type error is raised" do
      assert_raise(ArgumentError) do
        ModelForAttributesTest.attribute :foo, :unknown
      end
    end
  end
end

big_integer.rb

# frozen_string_literal: true

require "active_model/type/integer"

module ActiveModel
  module Type
    # Attribute type for integers that can be serialized to an unlimited number
    # of bytes. This type is registered under the +:big_integer+ key.
    #
    #   class Person
    #     include ActiveModel::Attributes
    #
    #     attribute :id, :big_integer
    #   end
    #
    #   person = Person.new
    #   person.id = "18_000_000_000"
    #
    #   person.id # => 18000000000
    #
    # All casting and serialization are performed in the same way as the
    # standard ActiveModel::Type::Integer type.
    class BigInteger < Integer
      private
        def max_value
          ::Float::INFINITY
        end
    end
  end
end

big_integer_test.rb

# frozen_string_literal: true

require "cases/helper"

module ActiveModel
  module Type
    class BigIntegerTest < ActiveModel::TestCase
      def test_type_cast_big_integer
        type = Type::BigInteger.new
        assert_equal 1, type.cast(1)
        assert_equal 1, type.cast("1")
      end

      def test_small_values
        type = Type::BigInteger.new
        assert_equal(-9999999999999999999999999999999, type.serialize(-9999999999999999999999999999999))
      end

      def test_large_values
        type = Type::BigInteger.new
        assert_equal 9999999999999999999999999999999, type.serialize(9999999999999999999999999999999)
      end
    end
  end
end

binary.rb

# frozen_string_literal: true

module ActiveModel
  module Type
    # Attribute type for representation of binary data. This type is registered
    # under the +:binary+ key.
    #
    # Non-string values are coerced to strings using their +to_s+ method.
    class Binary < Value
      def type
        :binary
      end

      def binary?
        true
      end

      def cast(value)
        if value.is_a?(Data)
          value.to_s
        else
          super
        end
      end

      def serialize(value)
        return if value.nil?
        Data.new(super)
      end

      def changed_in_place?(raw_old_value, value)
        old_value = deserialize(raw_old_value)
        old_value != value
      end

      class Data # :nodoc:
        def initialize(value)
          @value = value.to_s
        end

        def to_s
          @value
        end
        alias_method :to_str, :to_s

        def hex
          @value.unpack1("H*")
        end

        def ==(other)
          other == to_s || super
        end
      end
    end
  end
end

binary_test.rb

# frozen_string_literal: true

require "cases/helper"

module ActiveModel
  module Type
    class BinaryTest < ActiveModel::TestCase
      def test_type_cast_binary
        type = Type::Binary.new
        assert_nil type.cast(nil)
        assert_equal "1", type.cast("1")
        assert_equal 1, type.cast(1)
      end
    end
  end
end

blog_post.rb

# frozen_string_literal: true

module Blog
  def self.use_relative_model_naming?
    true
  end

  class Post
    extend ActiveModel::Naming
  end
end

boolean.rb

# frozen_string_literal: true

module ActiveModel
  module Type
    # A class that behaves like a boolean type, including rules for coercion of
    # user input.
    #
    # - <tt>"false"</tt>, <tt>"f"</tt>, <tt>"0"</tt>, +0+ or any other value in
    #   +FALSE_VALUES+ will be coerced to +false+.
    # - Empty strings are coerced to +nil+.
    # - All other values will be coerced to +true+.
    class Boolean < Value
      FALSE_VALUES = [
        false, 0,
        "0", :"0",
        "f", :f,
        "F", :F,
        "false", :false,
        "FALSE", :FALSE,
        "off", :off,
        "OFF", :OFF,
      ].to_set.freeze

      def type # :nodoc:
        :boolean
      end

      def serialize(value) # :nodoc:
        cast(value)
      end

      private
        def cast_value(value)
          if value == ""
            nil
          else
            !FALSE_VALUES.include?(value)
          end
        end
    end
  end
end

boolean_test.rb

# frozen_string_literal: true

require "cases/helper"

module ActiveModel
  module Type
    class BooleanTest < ActiveModel::TestCase
      def test_type_cast_boolean
        type = Type::Boolean.new
        assert_predicate type.cast(""), :nil?
        assert_predicate type.cast(nil), :nil?

        assert type.cast(true)
        assert type.cast(1)
        assert type.cast("1")
        assert type.cast("t")
        assert type.cast("T")
        assert type.cast("true")
        assert type.cast("TRUE")
        assert type.cast("on")
        assert type.cast("ON")
        assert type.cast(" ")
        assert type.cast("\u3000\r\n")
        assert type.cast("\u0000")
        assert type.cast("SOMETHING RANDOM")
        assert type.cast(:"1")
        assert type.cast(:t)
        assert type.cast(:T)
        assert type.cast(:true)
        assert type.cast(:TRUE)
        assert type.cast(:on)
        assert type.cast(:ON)

        # explicitly check for false vs nil
        assert_equal false, type.cast(false)
        assert_equal false, type.cast(0)
        assert_equal false, type.cast("0")
        assert_equal false, type.cast("f")
        assert_equal false, type.cast("F")
        assert_equal false, type.cast("false")
        assert_equal false, type.cast("FALSE")
        assert_equal false, type.cast("off")
        assert_equal false, type.cast("OFF")
        assert_equal false, type.cast(:"0")
        assert_equal false, type.cast(:f)
        assert_equal false, type.cast(:F)
        assert_equal false, type.cast(:false)
        assert_equal false, type.cast(:FALSE)
        assert_equal false, type.cast(:off)
        assert_equal false, type.cast(:OFF)
      end
    end
  end
end

builder.rb

# frozen_string_literal: true

require "active_model/attribute"

module ActiveModel
  class AttributeSet # :nodoc:
    class Builder # :nodoc:
      attr_reader :types, :default_attributes

      def initialize(types, default_attributes = {})
        @types = types
        @default_attributes = default_attributes
      end

      def build_from_database(values = {}, additional_types = {})
        LazyAttributeSet.new(values, types, additional_types, default_attributes)
      end
    end
  end

  class LazyAttributeSet < AttributeSet # :nodoc:
    def initialize(values, types, additional_types, default_attributes, attributes = {})
      super(attributes)
      @values = values
      @types = types
      @additional_types = additional_types
      @default_attributes = default_attributes
      @casted_values = {}
      @materialized = false
    end

    def key?(name)
      (values.key?(name) || types.key?(name) || @attributes.key?(name)) && self[name].initialized?
    end

    def keys
      keys = values.keys | types.keys | @attributes.keys
      keys.keep_if { |name| self[name].initialized? }
    end

    def fetch_value(name, &block)
      if attr = @attributes[name]
        return attr.value(&block)
      end

      @casted_values.fetch(name) do
        value_present = true
        value = values.fetch(name) { value_present = false }

        if value_present
          type = additional_types.fetch(name, types[name])
          @casted_values[name] = type.deserialize(value)
        else
          attr = default_attribute(name, value_present, value)
          attr.value(&block)
        end
      end
    end

    protected
      def attributes
        unless @materialized
          values.each_key { |key| self[key] }
          types.each_key { |key| self[key] }
          @materialized = true
        end
        @attributes
      end

    private
      attr_reader :values, :types, :additional_types, :default_attributes

      def default_attribute(
        name,
        value_present = true,
        value = values.fetch(name) { value_present = false }
      )
        type = additional_types.fetch(name, types[name])

        if value_present
          @attributes[name] = Attribute.from_database(name, value, type, @casted_values[name])
        elsif types.key?(name)
          if attr = default_attributes[name]
            @attributes[name] = attr.dup
          else
            @attributes[name] = Attribute.uninitialized(name, type)
          end
        else
          Attribute.null(name)
        end
      end
  end

  class LazyAttributeHash # :nodoc:
    delegate :transform_values, :each_value, :fetch, :except, to: :materialize

    def initialize(types, values, additional_types, default_attributes, delegate_hash = {})
      @types = types
      @values = values
      @additional_types = additional_types
      @materialized = false
      @delegate_hash = delegate_hash
      @default_attributes = default_attributes
    end

    def key?(key)
      delegate_hash.key?(key) || values.key?(key) || types.key?(key)
    end

    def [](key)
      delegate_hash[key] || assign_default_value(key)
    end

    def []=(key, value)
      delegate_hash[key] = value
    end

    def deep_dup
      dup.tap do |copy|
        copy.instance_variable_set(:@delegate_hash, delegate_hash.transform_values(&:dup))
      end
    end

    def initialize_dup(_)
      @delegate_hash = Hash[delegate_hash]
      super
    end

    def each_key(&block)
      keys = types.keys | values.keys | delegate_hash.keys
      keys.each(&block)
    end

    def ==(other)
      if other.is_a?(LazyAttributeHash)
        materialize == other.materialize
      else
        materialize == other
      end
    end

    def marshal_dump
      [@types, @values, @additional_types, @default_attributes, @delegate_hash]
    end

    def marshal_load(values)
      initialize(*values)
    end

    protected
      def materialize
        unless @materialized
          values.each_key { |key| self[key] }
          types.each_key { |key| self[key] }
          unless frozen?
            @materialized = true
          end
        end
        delegate_hash
      end

    private
      attr_reader :types, :values, :additional_types, :delegate_hash, :default_attributes

      def assign_default_value(name)
        type = additional_types.fetch(name, types[name])
        value_present = true
        value = values.fetch(name) { value_present = false }

        if value_present
          delegate_hash[name] = Attribute.from_database(name, value, type)
        elsif types.key?(name)
          attr = default_attributes[name]
          if attr
            delegate_hash[name] = attr.dup
          else
            delegate_hash[name] = Attribute.uninitialized(name, type)
          end
        end
      end
  end
end

callbacks.rb

# frozen_string_literal: true

module ActiveModel
  module Validations
    # == Active \Model \Validation \Callbacks
    #
    # Provides an interface for any class to have +before_validation+ and
    # +after_validation+ callbacks.
    #
    # First, include ActiveModel::Validations::Callbacks from the class you are
    # creating:
    #
    #   class MyModel
    #     include ActiveModel::Validations::Callbacks
    #
    #     before_validation :do_stuff_before_validation
    #     after_validation  :do_stuff_after_validation
    #   end
    #
    # Like other <tt>before_*</tt> callbacks if +before_validation+ throws
    # +:abort+ then <tt>valid?</tt> will not be called.
    module Callbacks
      extend ActiveSupport::Concern

      included do
        include ActiveSupport::Callbacks
        define_callbacks :validation,
                         skip_after_callbacks_if_terminated: true,
                         scope: [:kind, :name]
      end

      module ClassMethods
        # Defines a callback that will get called right before validation.
        #
        #   class Person
        #     include ActiveModel::Validations
        #     include ActiveModel::Validations::Callbacks
        #
        #     attr_accessor :name
        #
        #     validates_length_of :name, maximum: 6
        #
        #     before_validation :remove_whitespaces
        #
        #     private
        #
        #     def remove_whitespaces
        #       name.strip!
        #     end
        #   end
        #
        #   person = Person.new
        #   person.name = '  bob  '
        #   person.valid? # => true
        #   person.name   # => "bob"
        def before_validation(*args, &block)
          options = args.extract_options!

          set_options_for_callback(options)

          set_callback(:validation, :before, *args, options, &block)
        end

        # Defines a callback that will get called right after validation.
        #
        #   class Person
        #     include ActiveModel::Validations
        #     include ActiveModel::Validations::Callbacks
        #
        #     attr_accessor :name, :status
        #
        #     validates_presence_of :name
        #
        #     after_validation :set_status
        #
        #     private
        #
        #     def set_status
        #       self.status = errors.empty?
        #     end
        #   end
        #
        #   person = Person.new
        #   person.name = ''
        #   person.valid? # => false
        #   person.status # => false
        #   person.name = 'bob'
        #   person.valid? # => true
        #   person.status # => true
        def after_validation(*args, &block)
          options = args.extract_options!
          options = options.dup
          options[:prepend] = true

          set_options_for_callback(options)

          set_callback(:validation, :after, *args, options, &block)
        end

        private
          def set_options_for_callback(options)
            if options.key?(:on)
              options[:on] = Array(options[:on])
              options[:if] = [
                ->(o) {
                  !(options[:on] & Array(o.validation_context)).empty?
                },
                *options[:if]
              ]
            end
          end
      end

    private
      # Override run_validations! to include callbacks.
      def run_validations!
        _run_validation_callbacks { super }
      end
    end
  end
end

callbacks_test.rb

# frozen_string_literal: true

require "cases/helper"

class Dog
  include ActiveModel::Validations
  include ActiveModel::Validations::Callbacks

  attr_accessor :name, :history

  def initialize
    @history = []
  end
end

class DogWithMethodCallbacks < Dog
  before_validation :set_before_validation_marker
  after_validation :set_after_validation_marker

  def set_before_validation_marker; history << "before_validation_marker"; end
  def set_after_validation_marker;  history << "after_validation_marker" ; end
end

class DogValidatorsAreProc < Dog
  before_validation { history << "before_validation_marker" }
  after_validation  { history << "after_validation_marker" }
end

class DogWithTwoValidators < Dog
  before_validation { history << "before_validation_marker1" }
  before_validation { history << "before_validation_marker2" }
end

class DogBeforeValidatorReturningFalse < Dog
  before_validation { false }
  before_validation { history << "before_validation_marker2" }
end

class DogBeforeValidatorThrowingAbort < Dog
  before_validation { throw :abort }
  before_validation { history << "before_validation_marker2" }
end

class DogAfterValidatorReturningFalse < Dog
  after_validation { false }
  after_validation { history << "after_validation_marker" }
end

class DogWithMissingName < Dog
  before_validation { history << "before_validation_marker" }
  validates_presence_of :name
end

class DogValidatorWithOnCondition < Dog
  before_validation :set_before_validation_marker, on: :create
  after_validation :set_after_validation_marker, on: :create

  def set_before_validation_marker; history << "before_validation_marker"; end
  def set_after_validation_marker;  history << "after_validation_marker" ; end
end

class DogValidatorWithOnMultipleCondition < Dog
  before_validation :set_before_validation_marker_on_context_a, on: :context_a
  before_validation :set_before_validation_marker_on_context_b, on: :context_b
  after_validation :set_after_validation_marker_on_context_a, on: :context_a
  after_validation :set_after_validation_marker_on_context_b, on: :context_b

  def set_before_validation_marker_on_context_a; history << "before_validation_marker on context_a"; end
  def set_before_validation_marker_on_context_b; history << "before_validation_marker on context_b"; end
  def set_after_validation_marker_on_context_a;  history << "after_validation_marker on context_a" ; end
  def set_after_validation_marker_on_context_b;  history << "after_validation_marker on context_b" ; end
end

class DogValidatorWithIfCondition < Dog
  before_validation :set_before_validation_marker1, if: -> { true }
  before_validation :set_before_validation_marker2, if: -> { false }

  after_validation :set_after_validation_marker1, if: -> { true }
  after_validation :set_after_validation_marker2, if: -> { false }

  def set_before_validation_marker1; history << "before_validation_marker1"; end
  def set_before_validation_marker2; history << "before_validation_marker2" ; end

  def set_after_validation_marker1; history << "after_validation_marker1"; end
  def set_after_validation_marker2; history << "after_validation_marker2" ; end
end

class CallbacksWithMethodNamesShouldBeCalled < ActiveModel::TestCase
  def test_if_condition_is_respected_for_before_validation
    d = DogValidatorWithIfCondition.new
    d.valid?
    assert_equal ["before_validation_marker1", "after_validation_marker1"], d.history
  end

  def test_on_condition_is_respected_for_validation_with_matching_context
    d = DogValidatorWithOnCondition.new
    d.valid?(:create)
    assert_equal ["before_validation_marker", "after_validation_marker"], d.history
  end

  def test_on_condition_is_respected_for_validation_without_matching_context
    d = DogValidatorWithOnCondition.new
    d.valid?(:save)
    assert_equal [], d.history
  end

  def test_on_condition_is_respected_for_validation_without_context
    d = DogValidatorWithOnCondition.new
    d.valid?
    assert_equal [], d.history
  end

  def test_on_multiple_condition_is_respected_for_validation_with_matching_context
    d = DogValidatorWithOnMultipleCondition.new
    d.valid?(:context_a)
    assert_equal ["before_validation_marker on context_a", "after_validation_marker on context_a"], d.history

    d = DogValidatorWithOnMultipleCondition.new
    d.valid?(:context_b)
    assert_equal ["before_validation_marker on context_b", "after_validation_marker on context_b"], d.history

    d = DogValidatorWithOnMultipleCondition.new
    d.valid?([:context_a, :context_b])
    assert_equal([
      "before_validation_marker on context_a",
      "before_validation_marker on context_b",
      "after_validation_marker on context_a",
      "after_validation_marker on context_b"
    ], d.history)
  end

  def test_on_multiple_condition_is_respected_for_validation_without_matching_context
    d = DogValidatorWithOnMultipleCondition.new
    d.valid?(:save)
    assert_equal [], d.history
  end

  def test_on_multiple_condition_is_respected_for_validation_without_context
    d = DogValidatorWithOnMultipleCondition.new
    d.valid?
    assert_equal [], d.history
  end

  def test_before_validation_and_after_validation_callbacks_should_be_called
    d = DogWithMethodCallbacks.new
    d.valid?
    assert_equal ["before_validation_marker", "after_validation_marker"], d.history
  end

  def test_before_validation_and_after_validation_callbacks_should_be_called_with_proc
    d = DogValidatorsAreProc.new
    d.valid?
    assert_equal ["before_validation_marker", "after_validation_marker"], d.history
  end

  def test_before_validation_and_after_validation_callbacks_should_be_called_in_declared_order
    d = DogWithTwoValidators.new
    d.valid?
    assert_equal ["before_validation_marker1", "before_validation_marker2"], d.history
  end

  def test_further_callbacks_should_not_be_called_if_before_validation_throws_abort
    d = DogBeforeValidatorThrowingAbort.new
    output = d.valid?
    assert_equal [], d.history
    assert_equal false, output
  end

  def test_further_callbacks_should_be_called_if_before_validation_returns_false
    d = DogBeforeValidatorReturningFalse.new
    output = d.valid?
    assert_equal ["before_validation_marker2"], d.history
    assert_equal true, output
  end

  def test_further_callbacks_should_be_called_if_after_validation_returns_false
    d = DogAfterValidatorReturningFalse.new
    d.valid?
    assert_equal ["after_validation_marker"], d.history
  end

  def test_validation_test_should_be_done
    d = DogWithMissingName.new
    output = d.valid?
    assert_equal ["before_validation_marker"], d.history
    assert_equal false, output
  end

  def test_before_validation_does_not_mutate_the_if_options_array
    opts = []

    Class.new(Dog) do
      before_validation(if: opts, on: :create) { }
    end

    assert_empty opts
  end

  def test_after_validation_does_not_mutate_the_if_options_array
    opts = []

    Class.new(Dog) do
      after_validation(if: opts, on: :create) { }
    end

    assert_empty opts
  end
end

clusivity.rb

# frozen_string_literal: true

require "active_support/core_ext/range"

module ActiveModel
  module Validations
    module Clusivity # :nodoc:
      ERROR_MESSAGE = "An object with the method #include? or a proc, lambda or symbol is required, " \
                      "and must be supplied as the :in (or :within) option of the configuration hash"

      def check_validity!
        unless delimiter.respond_to?(:include?) || delimiter.respond_to?(:call) || delimiter.respond_to?(:to_sym)
          raise ArgumentError, ERROR_MESSAGE
        end
      end

    private
      def include?(record, value)
        members = if delimiter.respond_to?(:call)
          delimiter.call(record)
        elsif delimiter.respond_to?(:to_sym)
          record.send(delimiter)
        else
          delimiter
        end

        if value.is_a?(Array)
          value.all? { |v| members.public_send(inclusion_method(members), v) }
        else
          members.public_send(inclusion_method(members), value)
        end
      end

      def delimiter
        @delimiter ||= options[:in] || options[:within]
      end

      # After Ruby 2.2, <tt>Range#include?</tt> on non-number-or-time-ish ranges checks all
      # possible values in the range for equality, which is slower but more accurate.
      # <tt>Range#cover?</tt> uses the previous logic of comparing a value with the range
      # endpoints, which is fast but is only accurate on Numeric, Time, Date,
      # or DateTime ranges.
      def inclusion_method(enumerable)
        if enumerable.is_a? Range
          case enumerable.first
          when Numeric, Time, DateTime, Date
            :cover?
          else
            :include?
          end
        else
          :include?
        end
      end
    end
  end
end

comparability.rb

# frozen_string_literal: true

module ActiveModel
  module Validations
    module Comparability # :nodoc:
      COMPARE_CHECKS = { greater_than: :>, greater_than_or_equal_to: :>=,
        equal_to: :==, less_than: :<, less_than_or_equal_to: :<=,
        other_than: :!= }.freeze

      def option_value(record, option_value)
        case option_value
        when Proc
          option_value.call(record)
        when Symbol
          record.send(option_value)
        else
          option_value
        end
      end

      def error_options(value, option_value)
        options.except(*COMPARE_CHECKS.keys).merge!(
          count: option_value,
          value: value
        )
      end
    end
  end
end

comparison.rb

# frozen_string_literal: true

require "active_model/validations/comparability"

module ActiveModel
  module Validations
    class ComparisonValidator < EachValidator # :nodoc:
      include Comparability

      def check_validity!
        unless (options.keys & COMPARE_CHECKS.keys).any?
          raise ArgumentError, "Expected one of :greater_than, :greater_than_or_equal_to, "\
          ":equal_to, :less_than, :less_than_or_equal_to, or :other_than option to be supplied."
        end
      end

      def validate_each(record, attr_name, value)
        options.slice(*COMPARE_CHECKS.keys).each do |option, raw_option_value|
          option_value = option_value(record, raw_option_value)

          if value.nil? || value.blank?
            return record.errors.add(attr_name, :blank, **error_options(value, option_value))
          end

          unless value.public_send(COMPARE_CHECKS[option], option_value)
            record.errors.add(attr_name, option, **error_options(value, option_value))
          end
        rescue ArgumentError => e
          record.errors.add(attr_name, e.message)
        end
      end
    end

    module HelperMethods
      # Validates the value of a specified attribute fulfills all
      # defined comparisons with another value, proc, or attribute.
      #
      #   class Person < ActiveRecord::Base
      #     validates_comparison_of :value, greater_than: 'the sum of its parts'
      #   end
      #
      # Configuration options:
      # * <tt>:message</tt> - A custom error message (default is: "failed comparison").
      # * <tt>:greater_than</tt> - Specifies the value must be greater than the
      #   supplied value.
      # * <tt>:greater_than_or_equal_to</tt> - Specifies the value must be
      #   greater than or equal to the supplied value.
      # * <tt>:equal_to</tt> - Specifies the value must be equal to the supplied
      #   value.
      # * <tt>:less_than</tt> - Specifies the value must be less than the
      #   supplied value.
      # * <tt>:less_than_or_equal_to</tt> - Specifies the value must be less
      #   than or equal to the supplied value.
      # * <tt>:other_than</tt> - Specifies the value must not be equal to the
      #   supplied value.
      #
      # There is also a list of default options supported by every validator:
      # +:if+, +:unless+, +:on+, +:allow_nil+, +:allow_blank+, and +:strict+ .
      # See ActiveModel::Validations::ClassMethods#validates for more information.
      #
      # The validator requires at least one of the following checks to be supplied.
      # Each will accept a proc, value, or a symbol which corresponds to a method:
      #
      # * <tt>:greater_than</tt>
      # * <tt>:greater_than_or_equal_to</tt>
      # * <tt>:equal_to</tt>
      # * <tt>:less_than</tt>
      # * <tt>:less_than_or_equal_to</tt>
      # * <tt>:other_than</tt>
      #
      # For example:
      #
      #   class Person < ActiveRecord::Base
      #     validates_comparison_of :birth_date, less_than_or_equal_to: -> { Date.today }
      #     validates_comparison_of :preferred_name, other_than: :given_name, allow_nil: true
      #   end
      def validates_comparison_of(*attr_names)
        validates_with ComparisonValidator, _merge_attributes(attr_names)
      end
    end
  end
end

comparison_validation_test.rb

# frozen_string_literal: true

require "cases/helper"

require "models/topic"
require "models/person"

class ComparisonValidationTest < ActiveModel::TestCase
  def teardown
    Topic.clear_validators!
  end

  def test_validates_comparison_with_greater_than_using_numeric
    Topic.validates_comparison_of :approved, greater_than: 10

    assert_invalid_values([-12, 10], "must be greater than 10")
    assert_valid_values([11])
  end

  def test_validates_comparison_with_greater_than_using_date
    date_value = Date.parse("2020-08-02")
    Topic.validates_comparison_of :approved, greater_than: date_value

    assert_invalid_values([
      Date.parse("2019-08-03"),
      Date.parse("2020-07-03"),
      Date.parse("2020-08-01"),
      Date.parse("2020-08-02"),
      DateTime.new(2020, 8, 1, 12, 34)], "must be greater than 2020-08-02")
    assert_valid_values([Date.parse("2020-08-03"), DateTime.new(2020, 8, 2, 12, 34)])
  end

  def test_validates_comparison_with_greater_than_using_time
    time_value = Time.at(1596285240)
    Topic.validates_comparison_of :approved, greater_than: time_value

    assert_invalid_values([
      Time.at(1596285240),
      Time.at(1593714600)], "must be greater than #{time_value}")
    assert_valid_values([Time.at(1596371640), Time.at(1596393000)])
  end

  def test_validates_comparison_with_greater_than_using_string
    Topic.validates_comparison_of :approved, greater_than: "cat"

    assert_invalid_values(["ant", "cat"], "must be greater than cat")
    assert_valid_values(["dog", "whale"])
  end

  def test_validates_comparison_with_greater_than_or_equal_to_using_numeric
    Topic.validates_comparison_of :approved, greater_than_or_equal_to: 10

    assert_invalid_values([-12, 5], "must be greater than or equal to 10")
    assert_valid_values([11, 10])
  end

  def test_validates_comparison_with_greater_than_or_equal_to_using_date
    date_value = Date.parse("2020-08-02")
    Topic.validates_comparison_of :approved, greater_than_or_equal_to: date_value

    assert_invalid_values([
      Date.parse("2019-08-03"),
      Date.parse("2020-07-03"),
      Date.parse("2020-08-01"),
      DateTime.new(2020, 8, 1, 12, 34)], "must be greater than or equal to 2020-08-02")
    assert_valid_values([Date.parse("2020-08-03"), DateTime.new(2020, 8, 2, 12, 34), Date.parse("2020-08-02")])
  end

  def test_validates_comparison_with_greater_than_or_equal_to_using_time
    time_value = Time.at(1596285240)
    Topic.validates_comparison_of :approved, greater_than_or_equal_to: time_value

    assert_invalid_values([
      Time.at(1564662840),
      Time.at(1596285230)], "must be greater than or equal to #{time_value}")
    assert_valid_values([Time.at(1596285240), Time.at(1596285241)])
  end

  def test_validates_comparison_with_greater_than_or_equal_to_using_string
    Topic.validates_comparison_of :approved, greater_than_or_equal_to: "cat"

    assert_invalid_values(["ant"], "must be greater than or equal to cat")
    assert_valid_values(["cat", "dog", "whale"])
  end

  def test_validates_comparison_with_equal_to_using_numeric
    Topic.validates_comparison_of :approved, equal_to: 10

    assert_invalid_values([-12, 5, 11], "must be equal to 10")
    assert_valid_values([10])
  end

  def test_validates_comparison_with_equal_to_using_date
    date_value = Date.parse("2020-08-02")
    Topic.validates_comparison_of :approved, equal_to: date_value

    assert_invalid_values([
      Date.parse("2019-08-03"),
      Date.parse("2020-07-03"),
      Date.parse("2020-08-01"),
      DateTime.new(2020, 8, 1, 12, 34),
      Date.parse("2020-08-03"),
      DateTime.new(2020, 8, 2, 12, 34)], "must be equal to 2020-08-02")
    assert_valid_values([Date.parse("2020-08-02"), DateTime.new(2020, 8, 2, 0, 0)])
  end

  def test_validates_comparison_with_equal_to_using_time
    time_value = Time.at(1596285240)
    Topic.validates_comparison_of :approved, equal_to: time_value

    assert_invalid_values([
      Time.at(1564662840),
      Time.at(1596285230)], "must be equal to #{time_value}")
    assert_valid_values([Time.at(1596285240)])
  end

  def test_validates_comparison_with_equal_to_using_string
    Topic.validates_comparison_of :approved, equal_to: "cat"

    assert_invalid_values(["dog", "whale"], "must be equal to cat")
    assert_valid_values(["cat"])
  end

  def test_validates_comparison_with_less_than_using_numeric
    Topic.validates_comparison_of :approved, less_than: 10

    assert_invalid_values([11, 10], "must be less than 10")
    assert_valid_values([-12, -5, 5])
  end

  def test_validates_comparison_with_less_than_using_date
    date_value = Date.parse("2020-08-02")
    Topic.validates_comparison_of :approved, less_than: date_value

    assert_invalid_values([
      Date.parse("2020-08-02"),
      Date.parse("2020-08-03"),
      DateTime.new(2020, 8, 2, 12, 34)], "must be less than 2020-08-02")
    assert_valid_values([Date.parse("2019-08-03"),
      Date.parse("2020-07-03"),
      Date.parse("2020-08-01"),
      DateTime.new(2020, 8, 1, 12, 34)])
  end

  def test_validates_comparison_with_less_than_using_time
    time_value = Time.at(1596285240)
    Topic.validates_comparison_of :approved, less_than: time_value

    assert_invalid_values([
      Time.at(1596371640),
      Time.at(1596393000)], "must be less than #{time_value}")
    assert_valid_values([Time.at(1596285239), Time.at(1593714600)])
  end

  def test_validates_comparison_with_less_than_using_string
    Topic.validates_comparison_of :approved, less_than: "dog"

    assert_invalid_values(["whale"], "must be less than dog")
    assert_valid_values(["ant", "cat"])
  end

  def test_validates_comparison_with_less_than_or_equal_to_using_numeric
    Topic.validates_comparison_of :approved, less_than_or_equal_to: 10

    assert_invalid_values([12], "must be less than or equal to 10")
    assert_valid_values([-11, 5, 10])
  end

  def test_validates_comparison_with_less_than_or_equal_to_using_date
    date_value = Date.parse("2020-08-02")
    Topic.validates_comparison_of :approved, less_than_or_equal_to: date_value

    assert_invalid_values([
      Date.parse("2020-08-03"),
      DateTime.new(2020, 8, 2, 12, 34)], "must be less than or equal to 2020-08-02")
    assert_valid_values([Date.parse("2019-08-03"),
      Date.parse("2020-07-03"),
      Date.parse("2020-08-01"),
      Date.parse("2020-08-02"),
      DateTime.new(2020, 8, 1, 12, 34)])
  end

  def test_validates_comparison_with_less_than_or_equal_to_using_time
    time_value = Time.at(1596285240)
    Topic.validates_comparison_of :approved, less_than_or_equal_to: time_value

    assert_invalid_values([
      Time.at(1598963640),
      Time.at(1596285241)], "must be less than or equal to #{time_value}")
    assert_valid_values([Time.at(1596285240), Time.at(1596285230)])
  end

  def test_validates_comparison_with_less_than_or_equal_to_using_string
    Topic.validates_comparison_of :approved, less_than_or_equal_to: "dog"

    assert_invalid_values(["whale"], "must be less than or equal to dog")
    assert_valid_values(["ant", "cat", "dog"])
  end

  def test_validates_comparison_with_other_than_using_numeric
    Topic.validates_comparison_of :approved, other_than: 10

    assert_invalid_values([10], "must be other than 10")
    assert_valid_values([-12, 5, 11])
  end

  def test_validates_comparison_with_other_than_using_date
    date_value = Date.parse("2020-08-02")
    Topic.validates_comparison_of :approved, other_than: date_value

    assert_invalid_values([Date.parse("2020-08-02"), DateTime.new(2020, 8, 2, 0, 0)], "must be other than 2020-08-02")
    assert_valid_values([
      Date.parse("2019-08-03"),
      Date.parse("2020-07-03"),
      Date.parse("2020-08-01"),
      DateTime.new(2020, 8, 1, 12, 34),
      Date.parse("2020-08-03"),
      DateTime.new(2020, 8, 2, 12, 34)])
  end

  def test_validates_comparison_with_other_than_using_time
    time_value = Time.at(1596285240)
    Topic.validates_comparison_of :approved, other_than: time_value

    assert_invalid_values([Time.at(1596285240)], "must be other than #{time_value}")
    assert_valid_values([Time.at(1564662840), Time.at(1596285230)])
  end

  def test_validates_comparison_with_other_than_using_string
    Topic.validates_comparison_of :approved, other_than: "whale"

    assert_invalid_values(["whale"], "must be other than whale")
    assert_valid_values(["ant", "cat", "dog"])
  end

  def test_validates_comparison_with_proc
    Topic.define_method(:requested) { Date.new(2020, 8, 1) }
    Topic.validates_comparison_of :approved, greater_than_or_equal_to: Proc.new(&:requested)

    assert_invalid_values([Date.new(2020, 7, 1), Date.new(2019, 7, 1), DateTime.new(2020, 7, 1, 22, 34)], "must be greater than or equal to 2020-08-01")
    assert_valid_values([Date.new(2020, 8, 2), DateTime.new(2021, 8, 1)])
  ensure
    Topic.remove_method :requested
  end

  def test_validates_comparison_with_method
    Topic.define_method(:requested) { Date.new(2020, 8, 1) }
    Topic.validates_comparison_of :approved, greater_than_or_equal_to: :requested

    assert_invalid_values([Date.new(2020, 7, 1), Date.new(2019, 7, 1), DateTime.new(2020, 7, 1, 22, 34)], "must be greater than or equal to 2020-08-01")
    assert_valid_values([Date.new(2020, 8, 2), DateTime.new(2021, 8, 1)])
  ensure
    Topic.remove_method :requested
  end

  def test_validates_comparison_with_custom_compare
    custom = Struct.new(:amount) {
      include Comparable

      def <=>(other)
        amount % 100 <=> other.amount % 100
      end
    }
    Topic.validates_comparison_of :approved, greater_than_or_equal_to: custom.new(1150)

    assert_invalid_values([custom.new(530), custom.new(2325)])
    assert_valid_values([custom.new(575), custom.new(250), custom.new(1999)])
  end

  def test_validates_comparison_with_blank_allowed
    Topic.validates_comparison_of :approved, greater_than: "cat", allow_blank: true

    assert_invalid_values(["ant"])
    assert_valid_values([nil, ""])
  end

  def test_validates_comparison_with_nil_allowed
    Topic.validates_comparison_of :approved, less_than: 100, allow_nil: true

    assert_invalid_values([200])
    assert_valid_values([nil, 50])
  end

  def test_validates_comparison_of_incomparables
    Topic.validates_comparison_of :approved, less_than: "cat"

    assert_invalid_values([12], "comparison of Integer with String failed")
    assert_invalid_values([nil])
    assert_valid_values([])
  end

  def test_validates_comparison_of_multiple_values
    Topic.validates_comparison_of :approved, other_than: 17, greater_than: 13

    assert_invalid_values([12, nil, 17])
    assert_valid_values([15])
  end

  def test_validates_comparison_of_no_options
    error = assert_raises(ArgumentError) do
        Topic.validates_comparison_of(:approved)
      end
    assert_equal "Expected one of :greater_than, :greater_than_or_equal_to, :equal_to," \
                 " :less_than, :less_than_or_equal_to, or :other_than option to be supplied.", error.message
  end

  private
    def assert_invalid_values(values, error = nil)
      with_each_topic_approved_value(values) do |topic, value|
        assert topic.invalid?, "#{value.inspect} failed comparison"
        assert topic.errors[:approved].any?, "FAILED for #{value.inspect}"
        assert_equal error, topic.errors[:approved].first if error
      end
    end

    def assert_valid_values(values)
      with_each_topic_approved_value(values) do |topic, value|
        assert topic.valid?, "#{value.inspect} failed comparison with validation error: #{topic.errors[:approved].first}"
      end
    end

    def with_each_topic_approved_value(values)
      topic = Topic.new(title: "comparison test", content: "whatever")
      values.each do |value|
        topic.approved = value
        yield topic, value
      end
    end
end

conditional_validation_test.rb

# frozen_string_literal: true

require "cases/helper"

require "models/topic"

class ConditionalValidationTest < ActiveModel::TestCase
  def teardown
    Topic.clear_validators!
  end

  def test_if_validation_using_method_true
    # When the method returns true
    Topic.validates_length_of(:title, maximum: 5, too_long: "hoo %{count}", if: :condition_is_true)
    t = Topic.new("title" => "uhohuhoh", "content" => "whatever")
    assert_predicate t, :invalid?
    assert_predicate t.errors[:title], :any?
    assert_equal ["hoo 5"], t.errors["title"]
  end

  def test_if_validation_using_array_of_true_methods
    Topic.validates_length_of(:title, maximum: 5, too_long: "hoo %{count}", if: [:condition_is_true, :condition_is_true])
    t = Topic.new("title" => "uhohuhoh", "content" => "whatever")
    assert_predicate t, :invalid?
    assert_predicate t.errors[:title], :any?
    assert_equal ["hoo 5"], t.errors["title"]
  end

  def test_unless_validation_using_array_of_false_methods
    Topic.validates_length_of(:title, maximum: 5, too_long: "hoo %{count}", unless: [:condition_is_false, :condition_is_false])
    t = Topic.new("title" => "uhohuhoh", "content" => "whatever")
    assert_predicate t, :invalid?
    assert_predicate t.errors[:title], :any?
    assert_equal ["hoo 5"], t.errors["title"]
  end

  def test_unless_validation_using_method_true
    # When the method returns true
    Topic.validates_length_of(:title, maximum: 5, too_long: "hoo %{count}", unless: :condition_is_true)
    t = Topic.new("title" => "uhohuhoh", "content" => "whatever")
    assert_predicate t, :valid?
    assert_empty t.errors[:title]
  end

  def test_if_validation_using_array_of_true_and_false_methods
    Topic.validates_length_of(:title, maximum: 5, too_long: "hoo %{count}", if: [:condition_is_true, :condition_is_false])
    t = Topic.new("title" => "uhohuhoh", "content" => "whatever")
    assert_predicate t, :valid?
    assert_empty t.errors[:title]
  end

  def test_unless_validation_using_array_of_true_and_false_methods
    Topic.validates_length_of(:title, maximum: 5, too_long: "hoo %{count}", unless: [:condition_is_true, :condition_is_false])
    t = Topic.new("title" => "uhohuhoh", "content" => "whatever")
    assert_predicate t, :valid?
    assert_empty t.errors[:title]
  end

  def test_if_validation_using_method_false
    # When the method returns false
    Topic.validates_length_of(:title, maximum: 5, too_long: "hoo %{count}", if: :condition_is_false)
    t = Topic.new("title" => "uhohuhoh", "content" => "whatever")
    assert_predicate t, :valid?
    assert_empty t.errors[:title]
  end

  def test_unless_validation_using_method_false
    # When the method returns false
    Topic.validates_length_of(:title, maximum: 5, too_long: "hoo %{count}", unless: :condition_is_false)
    t = Topic.new("title" => "uhohuhoh", "content" => "whatever")
    assert_predicate t, :invalid?
    assert_predicate t.errors[:title], :any?
    assert_equal ["hoo 5"], t.errors["title"]
  end

  def test_if_validation_using_block_true
    # When the block returns true
    Topic.validates_length_of(:title, maximum: 5, too_long: "hoo %{count}",
      if: Proc.new { |r| r.content.size > 4 })
    t = Topic.new("title" => "uhohuhoh", "content" => "whatever")
    assert_predicate t, :invalid?
    assert_predicate t.errors[:title], :any?
    assert_equal ["hoo 5"], t.errors["title"]
  end

  def test_unless_validation_using_block_true
    # When the block returns true
    Topic.validates_length_of(:title, maximum: 5, too_long: "hoo %{count}",
      unless: Proc.new { |r| r.content.size > 4 })
    t = Topic.new("title" => "uhohuhoh", "content" => "whatever")
    assert_predicate t, :valid?
    assert_empty t.errors[:title]
  end

  def test_if_validation_using_block_false
    # When the block returns false
    Topic.validates_length_of(:title, maximum: 5, too_long: "hoo %{count}",
      if: Proc.new { |r| r.title != "uhohuhoh" })
    t = Topic.new("title" => "uhohuhoh", "content" => "whatever")
    assert_predicate t, :valid?
    assert_empty t.errors[:title]
  end

  def test_unless_validation_using_block_false
    # When the block returns false
    Topic.validates_length_of(:title, maximum: 5, too_long: "hoo %{count}",
      unless: Proc.new { |r| r.title != "uhohuhoh" })
    t = Topic.new("title" => "uhohuhoh", "content" => "whatever")
    assert_predicate t, :invalid?
    assert_predicate t.errors[:title], :any?
    assert_equal ["hoo 5"], t.errors["title"]
  end

  def test_validation_using_combining_if_true_and_unless_true_conditions
    Topic.validates_length_of(:title, maximum: 5, too_long: "hoo %{count}", if: :condition_is_true, unless: :condition_is_true)
    t = Topic.new("title" => "uhohuhoh", "content" => "whatever")
    assert_predicate t, :valid?
    assert_empty t.errors[:title]
  end

  def test_validation_using_combining_if_true_and_unless_false_conditions
    Topic.validates_length_of(:title, maximum: 5, too_long: "hoo %{count}", if: :condition_is_true, unless: :condition_is_false)
    t = Topic.new("title" => "uhohuhoh", "content" => "whatever")
    assert_predicate t, :invalid?
    assert_predicate t.errors[:title], :any?
    assert_equal ["hoo 5"], t.errors["title"]
  end
end

confirmation.rb

# frozen_string_literal: true

module ActiveModel
  module Validations
    class ConfirmationValidator < EachValidator # :nodoc:
      def initialize(options)
        super({ case_sensitive: true }.merge!(options))
        setup!(options[:class])
      end

      def validate_each(record, attribute, value)
        unless (confirmed = record.public_send("#{attribute}_confirmation")).nil?
          unless confirmation_value_equal?(record, attribute, value, confirmed)
            human_attribute_name = record.class.human_attribute_name(attribute)
            record.errors.add(:"#{attribute}_confirmation", :confirmation, **options.except(:case_sensitive).merge!(attribute: human_attribute_name))
          end
        end
      end

      private
        def setup!(klass)
          klass.attr_reader(*attributes.filter_map do |attribute|
            :"#{attribute}_confirmation" unless klass.method_defined?(:"#{attribute}_confirmation")
          end)

          klass.attr_writer(*attributes.filter_map do |attribute|
            :"#{attribute}_confirmation" unless klass.method_defined?(:"#{attribute}_confirmation=")
          end)
        end

        def confirmation_value_equal?(record, attribute, value, confirmed)
          if !options[:case_sensitive] && value.is_a?(String)
            value.casecmp(confirmed) == 0
          else
            value == confirmed
          end
        end
    end

    module HelperMethods
      # Encapsulates the pattern of wanting to validate a password or email
      # address field with a confirmation.
      #
      #   Model:
      #     class Person < ActiveRecord::Base
      #       validates_confirmation_of :user_name, :password
      #       validates_confirmation_of :email_address,
      #                                 message: 'should match confirmation'
      #     end
      #
      #   View:
      #     <%= password_field "person", "password" %>
      #     <%= password_field "person", "password_confirmation" %>
      #
      # The added +password_confirmation+ attribute is virtual; it exists only
      # as an in-memory attribute for validating the password. To achieve this,
      # the validation adds accessors to the model for the confirmation
      # attribute.
      #
      # NOTE: This check is performed only if +password_confirmation+ is not
      # +nil+. To require confirmation, make sure to add a presence check for
      # the confirmation attribute:
      #
      #   validates_presence_of :password_confirmation, if: :password_changed?
      #
      # Configuration options:
      # * <tt>:message</tt> - A custom error message (default is: "doesn't match
      #   <tt>%{translated_attribute_name}</tt>").
      # * <tt>:case_sensitive</tt> - Looks for an exact match. Ignored by
      #   non-text columns (+true+ by default).
      #
      # There is also a list of default options supported by every validator:
      # +:if+, +:unless+, +:on+, +:allow_nil+, +:allow_blank+, and +:strict+.
      # See ActiveModel::Validations::ClassMethods#validates for more information.
      def validates_confirmation_of(*attr_names)
        validates_with ConfirmationValidator, _merge_attributes(attr_names)
      end
    end
  end
end

confirmation_validation_test.rb

# frozen_string_literal: true

require "cases/helper"

require "models/topic"
require "models/person"

class ConfirmationValidationTest < ActiveModel::TestCase
  def teardown
    Topic.clear_validators!
  end

  def test_no_title_confirmation
    Topic.validates_confirmation_of(:title)

    t = Topic.new(author_name: "Plutarch")
    assert_predicate t, :valid?

    t.title_confirmation = "Parallel Lives"
    assert_predicate t, :invalid?

    t.title_confirmation = nil
    t.title = "Parallel Lives"
    assert_predicate t, :valid?

    t.title_confirmation = "Parallel Lives"
    assert_predicate t, :valid?
  end

  def test_title_confirmation
    Topic.validates_confirmation_of(:title)

    t = Topic.new("title" => "We should be confirmed", "title_confirmation" => "")
    assert_predicate t, :invalid?

    t.title_confirmation = "We should be confirmed"
    assert_predicate t, :valid?
  end

  def test_validates_confirmation_of_with_boolean_attribute
    Topic.validates_confirmation_of(:approved)

    t = Topic.new(approved: true, approved_confirmation: nil)
    assert_predicate t, :valid?

    t.approved_confirmation = false
    assert_predicate t, :invalid?

    t.approved_confirmation = true
    assert_predicate t, :valid?
  end

  def test_validates_confirmation_of_for_ruby_class
    Person.validates_confirmation_of :karma

    p = Person.new
    p.karma_confirmation = "None"
    assert_predicate p, :invalid?

    assert_equal ["doesn't match Karma"], p.errors[:karma_confirmation]

    p.karma = "None"
    assert_predicate p, :valid?
  ensure
    Person.clear_validators!
  end

  def test_title_confirmation_with_i18n_attribute
    @old_load_path, @old_backend = I18n.load_path.dup, I18n.backend
    I18n.load_path.clear
    I18n.backend = I18n::Backend::Simple.new
    I18n.backend.store_translations("en",
      errors: { messages: { confirmation: "doesn't match %{attribute}" } },
      activemodel: { attributes: { topic: { title: "Test Title" } } })

    Topic.validates_confirmation_of(:title)

    t = Topic.new("title" => "We should be confirmed", "title_confirmation" => "")
    assert_predicate t, :invalid?
    assert_equal ["doesn't match Test Title"], t.errors[:title_confirmation]
  ensure
    I18n.load_path.replace @old_load_path
    I18n.backend = @old_backend
    I18n.backend.reload!
  end

  test "does not override confirmation reader if present" do
    klass = Class.new do
      include ActiveModel::Validations

      def title_confirmation
        "expected title"
      end

      validates_confirmation_of :title
    end

    assert_equal "expected title", klass.new.title_confirmation,
     "confirmation validation should not override the reader"
  end

  test "does not override confirmation writer if present" do
    klass = Class.new do
      include ActiveModel::Validations

      def title_confirmation=(value)
        @title_confirmation = "expected title"
      end

      validates_confirmation_of :title
    end

    model = klass.new
    model.title_confirmation = "new title"
    assert_equal "expected title", model.title_confirmation,
     "confirmation validation should not override the writer"
  end

  def test_title_confirmation_with_case_sensitive_option_true
    Topic.validates_confirmation_of(:title, case_sensitive: true)

    t = Topic.new(title: "title", title_confirmation: "Title")
    assert_predicate t, :invalid?
  end

  def test_title_confirmation_with_case_sensitive_option_false
    Topic.validates_confirmation_of(:title, case_sensitive: false)

    t = Topic.new(title: "title", title_confirmation: "Title")
    assert_predicate t, :valid?
  end
end

contact.rb

# frozen_string_literal: true

class Contact
  extend ActiveModel::Naming
  include ActiveModel::Conversion
  include ActiveModel::Validations

  include ActiveModel::Serializers::JSON

  attr_accessor :id, :name, :age, :created_at, :awesome, :preferences
  attr_accessor :address, :friends, :contact

  def social
    %w(twitter github)
  end

  def network
    { git: :github }
  end

  def initialize(options = {})
    options.each { |name, value| public_send("#{name}=", value) }
  end

  def pseudonyms
    nil
  end

  def persisted?
    id
  end

  def attributes=(hash)
    hash.each do |k, v|
      instance_variable_set("@#{k}", v)
    end
  end

  def attributes
    instance_values.except("address", "friends", "contact")
  end
end

conversion.rb

# frozen_string_literal: true

module ActiveModel
  # == Active \Model \Conversion
  #
  # Handles default conversions: to_model, to_key, to_param, and to_partial_path.
  #
  # Let's take for example this non-persisted object.
  #
  #   class ContactMessage
  #     include ActiveModel::Conversion
  #
  #     # ContactMessage are never persisted in the DB
  #     def persisted?
  #       false
  #     end
  #   end
  #
  #   cm = ContactMessage.new
  #   cm.to_model == cm  # => true
  #   cm.to_key          # => nil
  #   cm.to_param        # => nil
  #   cm.to_partial_path # => "contact_messages/contact_message"
  module Conversion
    extend ActiveSupport::Concern

    # If your object is already designed to implement all of the \Active \Model
    # you can use the default <tt>:to_model</tt> implementation, which simply
    # returns +self+.
    #
    #   class Person
    #     include ActiveModel::Conversion
    #   end
    #
    #   person = Person.new
    #   person.to_model == person # => true
    #
    # If your model does not act like an \Active \Model object, then you should
    # define <tt>:to_model</tt> yourself returning a proxy object that wraps
    # your object with \Active \Model compliant methods.
    def to_model
      self
    end

    # Returns an Array of all key attributes if any of the attributes is set, whether or not
    # the object is persisted. Returns +nil+ if there are no key attributes.
    #
    #   class Person
    #     include ActiveModel::Conversion
    #     attr_accessor :id
    #
    #     def initialize(id)
    #       @id = id
    #     end
    #   end
    #
    #   person = Person.new(1)
    #   person.to_key # => [1]
    def to_key
      key = respond_to?(:id) && id
      key ? [key] : nil
    end

    # Returns a +string+ representing the object's key suitable for use in URLs,
    # or +nil+ if <tt>persisted?</tt> is +false+.
    #
    #   class Person
    #     include ActiveModel::Conversion
    #     attr_accessor :id
    #
    #     def initialize(id)
    #       @id = id
    #     end
    #
    #     def persisted?
    #       true
    #     end
    #   end
    #
    #   person = Person.new(1)
    #   person.to_param # => "1"
    def to_param
      (persisted? && key = to_key) ? key.join("-") : nil
    end

    # Returns a +string+ identifying the path associated with the object.
    # ActionPack uses this to find a suitable partial to represent the object.
    #
    #   class Person
    #     include ActiveModel::Conversion
    #   end
    #
    #   person = Person.new
    #   person.to_partial_path # => "people/person"
    def to_partial_path
      self.class._to_partial_path
    end

    module ClassMethods # :nodoc:
      # Provide a class level cache for #to_partial_path. This is an
      # internal method and should not be accessed directly.
      def _to_partial_path # :nodoc:
        @_to_partial_path ||= begin
          element = ActiveSupport::Inflector.underscore(ActiveSupport::Inflector.demodulize(name))
          collection = ActiveSupport::Inflector.tableize(name)
          "#{collection}/#{element}"
        end
      end
    end
  end
end

conversion_test.rb

# frozen_string_literal: true

require "cases/helper"
require "models/contact"
require "models/helicopter"

class ConversionTest < ActiveModel::TestCase
  test "to_model default implementation returns self" do
    contact = Contact.new
    assert_equal contact, contact.to_model
  end

  test "to_key default implementation returns nil for new records" do
    assert_nil Contact.new.to_key
  end

  test "to_key default implementation returns the id in an array for persisted records" do
    assert_equal [1], Contact.new(id: 1).to_key
  end

  test "to_param default implementation returns nil for new records" do
    assert_nil Contact.new.to_param
  end

  test "to_param default implementation returns a string of ids for persisted records" do
    assert_equal "1", Contact.new(id: 1).to_param
  end

  test "to_param returns the string joined by '-'" do
    assert_equal "abc-xyz", Contact.new(id: ["abc", "xyz"]).to_param
  end

  test "to_param returns nil if to_key is nil" do
    klass = Class.new(Contact) do
      def persisted?
        true
      end
    end

    assert_nil klass.new.to_param
  end

  test "to_partial_path default implementation returns a string giving a relative path" do
    assert_equal "contacts/contact", Contact.new.to_partial_path
    assert_equal "helicopters/helicopter", Helicopter.new.to_partial_path,
      "ActiveModel::Conversion#to_partial_path caching should be class-specific"
  end

  test "to_partial_path handles namespaced models" do
    assert_equal "helicopter/comanches/comanche", Helicopter::Comanche.new.to_partial_path
  end
end

custom_reader.rb

# frozen_string_literal: true

class CustomReader
  include ActiveModel::Validations

  def initialize(data = {})
    @data = data
  end

  def []=(key, value)
    @data[key] = value
  end

  def read_attribute_for_validation(key)
    @data[key]
  end
end

date.rb

# frozen_string_literal: true

module ActiveModel
  module Type
    # Attribute type for date representation. It is registered under the
    # +:date+ key.
    #
    #   class Person
    #     include ActiveModel::Attributes
    #
    #     attribute :birthday, :date
    #   end
    #
    #   person = Person.new
    #   person.birthday = "1989-07-13"
    #
    #   person.birthday.class # => Date
    #   person.birthday.year  # => 1989
    #   person.birthday.month # => 7
    #   person.birthday.day   # => 13
    #
    # String values are parsed using the ISO 8601 date format. Any other values
    # are cast using their +to_date+ method, if it exists.
    class Date < Value
      include Helpers::Timezone
      include Helpers::AcceptsMultiparameterTime.new

      def type
        :date
      end

      def type_cast_for_schema(value)
        value.to_fs(:db).inspect
      end

      private
        def cast_value(value)
          if value.is_a?(::String)
            return if value.empty?
            fast_string_to_date(value) || fallback_string_to_date(value)
          elsif value.respond_to?(:to_date)
            value.to_date
          else
            value
          end
        end

        ISO_DATE = /\A(\d{4})-(\d\d)-(\d\d)\z/
        def fast_string_to_date(string)
          if string =~ ISO_DATE
            new_date $1.to_i, $2.to_i, $3.to_i
          end
        end

        def fallback_string_to_date(string)
          new_date(*::Date._parse(string, false).values_at(:year, :mon, :mday))
        end

        def new_date(year, mon, mday)
          unless year.nil? || (year == 0 && mon == 0 && mday == 0)
            ::Date.new(year, mon, mday) rescue nil
          end
        end

        def value_from_multiparameter_assignment(*)
          time = super
          time && new_date(time.year, time.mon, time.mday)
        end
    end
  end
end

date_test.rb

# frozen_string_literal: true

require "cases/helper"

module ActiveModel
  module Type
    class DateTest < ActiveModel::TestCase
      def test_type_cast_date
        type = Type::Date.new
        assert_nil type.cast(nil)
        assert_nil type.cast("")
        assert_nil type.cast(" ")
        assert_nil type.cast("ABC")

        now = ::Time.now.utc
        values_hash = { 1 => now.year, 2 => now.mon, 3 => now.mday }
        date_string = now.strftime("%F")
        assert_equal date_string, type.cast(date_string).strftime("%F")
        assert_equal date_string, type.cast(values_hash).strftime("%F")
      end

      def test_returns_correct_year
        type = Type::Date.new

        time = ::Time.utc(1, 1, 1)
        date = ::Date.new(time.year, time.mon, time.mday)

        values_hash_for_multiparameter_assignment = { 1 => 1, 2 => 1, 3 => 1 }

        assert_equal date, type.cast(values_hash_for_multiparameter_assignment)
      end
    end
  end
end

date_time.rb

# frozen_string_literal: true

module ActiveModel
  module Type
    # Attribute type to represent dates and times. It is registered under the
    # +:datetime+ key.
    #
    #   class Event
    #     include ActiveModel::Attributes
    #
    #     attribute :start, :datetime
    #   end
    #
    #   event = Event.new
    #   event.start = "Wed, 04 Sep 2013 03:00:00 EAT"
    #
    #   event.start.class # => Time
    #   event.start.year  # => 2013
    #   event.start.month # => 9
    #   event.start.day   # => 4
    #   event.start.hour  # => 3
    #   event.start.min   # => 0
    #   event.start.sec   # => 0
    #   event.start.zone  # => "EAT"
    #
    # String values are parsed using the ISO 8601 datetime format. Partial
    # time-only formats are also accepted.
    #
    #   event.start = "06:07:08+09:00"
    #   event.start.utc # => 1999-12-31 21:07:08 UTC
    #
    # The degree of sub-second precision can be customized when declaring an
    # attribute:
    #
    #   class Event
    #     include ActiveModel::Attributes
    #
    #     attribute :start, :datetime, precision: 4
    #   end
    class DateTime < Value
      include Helpers::Timezone
      include Helpers::TimeValue
      include Helpers::AcceptsMultiparameterTime.new(
        defaults: { 4 => 0, 5 => 0 }
      )

      def type
        :datetime
      end

      private
        def cast_value(value)
          return apply_seconds_precision(value) unless value.is_a?(::String)
          return if value.empty?

          fast_string_to_time(value) || fallback_string_to_time(value)
        end

        # '0.123456' -> 123456
        # '1.123456' -> 123456
        def microseconds(time)
          time[:sec_fraction] ? (time[:sec_fraction] * 1_000_000).to_i : 0
        end

        def fallback_string_to_time(string)
          time_hash = ::Date._parse(string)
          time_hash[:sec_fraction] = microseconds(time_hash)

          new_time(*time_hash.values_at(:year, :mon, :mday, :hour, :min, :sec, :sec_fraction, :offset))
        end

        def value_from_multiparameter_assignment(values_hash)
          missing_parameters = [1, 2, 3].delete_if { |key| values_hash.key?(key) }
          unless missing_parameters.empty?
            raise ArgumentError, "Provided hash #{values_hash} doesn't contain necessary keys: #{missing_parameters}"
          end
          super
        end
    end
  end
end

date_time_test.rb

# frozen_string_literal: true

require "cases/helper"

module ActiveModel
  module Type
    class DateTimeTest < ActiveModel::TestCase
      def test_type_cast_datetime_and_timestamp
        type = Type::DateTime.new
        assert_nil type.cast(nil)
        assert_nil type.cast("")
        assert_nil type.cast("  ")
        assert_nil type.cast("ABC")

        datetime_string = ::Time.now.utc.strftime("%FT%T")
        assert_equal datetime_string, type.cast(datetime_string).strftime("%FT%T")
      end

      def test_string_to_time_with_timezone
        ["UTC", "US/Eastern"].each do |zone|
          with_timezone_config default: zone do
            type = Type::DateTime.new
            assert_equal ::Time.utc(2013, 9, 4, 0, 0, 0), type.cast("Wed, 04 Sep 2013 03:00:00 EAT")
          end
        end
      end

      def test_hash_to_time
        type = Type::DateTime.new
        assert_equal ::Time.utc(2018, 10, 15, 0, 0, 0), type.cast(1 => 2018, 2 => 10, 3 => 15)
      end

      def test_hash_with_wrong_keys
        type = Type::DateTime.new
        error = assert_raises(ArgumentError) { type.cast(a: 1) }
        assert_equal "Provided hash {:a=>1} doesn't contain necessary keys: [1, 2, 3]", error.message
      end

      private
        def with_timezone_config(default:)
          old_zone_default = ::Time.zone_default
          ::Time.zone_default = ::Time.find_zone(default)
          yield
        ensure
          ::Time.zone_default = old_zone_default
        end
    end
  end
end

decimal.rb

# frozen_string_literal: true

require "bigdecimal/util"

module ActiveModel
  module Type
    # Attribute type for decimal, high-precision floating point numeric
    # representation. It is registered under the +:decimal+ key.
    #
    #   class BagOfCoffee
    #     include ActiveModel::Attributes
    #
    #     attribute :weight, :decimal
    #   end
    #
    #   bag = BagOfCoffee.new
    #   bag.weight = "0.0001"
    #
    #   bag.weight # => 0.1e-3
    #
    # Numeric instances are converted to BigDecimal instances. Any other objects
    # are cast using their +to_d+ method, if it exists. If it does not exist,
    # the object is converted to a string using +to_s+, which is then coerced to
    # a BigDecimal using +to_d+.
    #
    # Decimal precision defaults to 18, and can be customized when declaring an
    # attribute:
    #
    #   class BagOfCoffee
    #     include ActiveModel::Attributes
    #
    #     attribute :weight, :decimal, precision: 24
    #   end
    class Decimal < Value
      include Helpers::Numeric
      BIGDECIMAL_PRECISION = 18

      def type
        :decimal
      end

      def type_cast_for_schema(value)
        value.to_s.inspect
      end

      private
        def cast_value(value)
          casted_value = \
            case value
            when ::Float
              convert_float_to_big_decimal(value)
            when ::Numeric
              BigDecimal(value, precision || BIGDECIMAL_PRECISION)
            when ::String
              begin
                value.to_d
              rescue ArgumentError
                BigDecimal(0)
              end
            else
              if value.respond_to?(:to_d)
                value.to_d
              else
                cast_value(value.to_s)
              end
            end

          apply_scale(casted_value)
        end

        def convert_float_to_big_decimal(value)
          if precision
            BigDecimal(apply_scale(value), float_precision)
          else
            value.to_d
          end
        end

        def float_precision
          if precision.to_i > ::Float::DIG + 1
            ::Float::DIG + 1
          else
            precision.to_i
          end
        end

        def apply_scale(value)
          if scale
            value.round(scale)
          else
            value
          end
        end
    end
  end
end

decimal_test.rb

# frozen_string_literal: true

require "cases/helper"

module ActiveModel
  module Type
    class DecimalTest < ActiveModel::TestCase
      def test_type_cast_decimal
        type = Decimal.new
        assert_equal BigDecimal("0"), type.cast(BigDecimal("0"))
        assert_equal BigDecimal("123"), type.cast(123.0)
        assert_equal BigDecimal("1"), type.cast(:"1")
      end

      def test_type_cast_decimal_from_invalid_string
        type = Decimal.new
        assert_nil type.cast("")
        assert_equal BigDecimal("1"), type.cast("1ignore")
        assert_equal BigDecimal("0"), type.cast("bad1")
        assert_equal BigDecimal("0"), type.cast("bad")
      end

      def test_type_cast_decimal_from_float_with_large_precision
        type = Decimal.new(precision: ::Float::DIG + 2)
        assert_equal BigDecimal("123.0"), type.cast(123.0)
      end

      def test_type_cast_from_float_with_unspecified_precision
        type = Decimal.new
        assert_equal 22.68.to_d, type.cast(22.68)
      end

      def test_type_cast_decimal_from_rational_with_precision
        type = Decimal.new(precision: 2)
        assert_equal BigDecimal("0.33"), type.cast(Rational(1, 3))
        assert_equal BigDecimal("0.67"), type.cast(Rational(2, 3))
      end

      def test_type_cast_decimal_from_rational_with_precision_and_scale
        type = Decimal.new(precision: 4, scale: 2)
        assert_equal BigDecimal("0.33"), type.cast(Rational(1, 3))
        assert_equal BigDecimal("0.67"), type.cast(Rational(2, 3))
      end

      def test_type_cast_decimal_from_rational_without_precision_defaults_to_18_36
        type = Decimal.new
        assert_equal BigDecimal("0.333333333333333333E0"), type.cast(Rational(1, 3))
        assert_equal BigDecimal("0.666666666666666667E0"), type.cast(Rational(2, 3))
      end

      def test_type_cast_decimal_from_object_responding_to_d
        value = Object.new
        def value.to_d
          BigDecimal("1")
        end
        type = Decimal.new
        assert_equal BigDecimal("1"), type.cast(value)
      end

      def test_changed?
        type = Decimal.new

        assert type.changed?(0.0, 0, "wibble")
        assert type.changed?(5.0, 0, "wibble")
        assert_not type.changed?(5.0, 5.0, "5.0wibble")
        assert_not type.changed?(5.0, 5.0, "5.0")
        assert_not type.changed?(-5.0, -5.0, "-5.0")
        assert_not type.changed?(5.0, 5.0, "0.5e+1")
        assert_not type.changed?(BigDecimal("0.0") / 0, BigDecimal("0.0") / 0, BigDecimal("0.0") / 0)
        assert type.changed?(BigDecimal("0.0") / 0, 0.0 / 0.0, 0.0 / 0.0)
      end

      def test_scale_is_applied_before_precision_to_prevent_rounding_errors
        type = Decimal.new(precision: 5, scale: 3)

        assert_equal BigDecimal("1.250"), type.cast(1.250473853637869)
        assert_equal BigDecimal("1.250"), type.cast("1.250473853637869")
      end
    end
  end
end

dirty.rb

# frozen_string_literal: true

require "active_model/attribute_mutation_tracker"

module ActiveModel
  # == Active \Model \Dirty
  #
  # Provides a way to track changes in your object in the same way as
  # Active Record does.
  #
  # The requirements for implementing ActiveModel::Dirty are:
  #
  # * <tt>include ActiveModel::Dirty</tt> in your object.
  # * Call <tt>define_attribute_methods</tt> passing each method you want to
  #   track.
  # * Call <tt>[attr_name]_will_change!</tt> before each change to the tracked
  #   attribute.
  # * Call <tt>changes_applied</tt> after the changes are persisted.
  # * Call <tt>clear_changes_information</tt> when you want to reset the changes
  #   information.
  # * Call <tt>restore_attributes</tt> when you want to restore previous data.
  #
  # A minimal implementation could be:
  #
  #   class Person
  #     include ActiveModel::Dirty
  #
  #     define_attribute_methods :name
  #
  #     def initialize
  #       @name = nil
  #     end
  #
  #     def name
  #       @name
  #     end
  #
  #     def name=(val)
  #       name_will_change! unless val == @name
  #       @name = val
  #     end
  #
  #     def save
  #       # do persistence work
  #
  #       changes_applied
  #     end
  #
  #     def reload!
  #       # get the values from the persistence layer
  #
  #       clear_changes_information
  #     end
  #
  #     def rollback!
  #       restore_attributes
  #     end
  #   end
  #
  # A newly instantiated +Person+ object is unchanged:
  #
  #   person = Person.new
  #   person.changed? # => false
  #
  # Change the name:
  #
  #   person.name = 'Bob'
  #   person.changed?       # => true
  #   person.name_changed?  # => true
  #   person.name_changed?(from: nil, to: "Bob") # => true
  #   person.name_was       # => nil
  #   person.name_change    # => [nil, "Bob"]
  #   person.name = 'Bill'
  #   person.name_change    # => [nil, "Bill"]
  #
  # Save the changes:
  #
  #   person.save
  #   person.changed?      # => false
  #   person.name_changed? # => false
  #
  # Reset the changes:
  #
  #   person.previous_changes         # => {"name" => [nil, "Bill"]}
  #   person.name_previously_changed? # => true
  #   person.name_previously_changed?(from: nil, to: "Bill") # => true
  #   person.name_previous_change     # => [nil, "Bill"]
  #   person.name_previously_was      # => nil
  #   person.reload!
  #   person.previous_changes         # => {}
  #
  # Rollback the changes:
  #
  #   person.name = "Uncle Bob"
  #   person.rollback!
  #   person.name          # => "Bill"
  #   person.name_changed? # => false
  #
  # Assigning the same value leaves the attribute unchanged:
  #
  #   person.name = 'Bill'
  #   person.name_changed? # => false
  #   person.name_change   # => nil
  #
  # Which attributes have changed?
  #
  #   person.name = 'Bob'
  #   person.changed # => ["name"]
  #   person.changes # => {"name" => ["Bill", "Bob"]}
  #
  # If an attribute is modified in-place then make use of
  # <tt>[attribute_name]_will_change!</tt> to mark that the attribute is changing.
  # Otherwise \Active \Model can't track changes to in-place attributes. Note
  # that Active Record can detect in-place modifications automatically. You do
  # not need to call <tt>[attribute_name]_will_change!</tt> on Active Record models.
  #
  #   person.name_will_change!
  #   person.name_change # => ["Bill", "Bill"]
  #   person.name << 'y'
  #   person.name_change # => ["Bill", "Billy"]
  module Dirty
    extend ActiveSupport::Concern
    include ActiveModel::AttributeMethods

    included do
      attribute_method_suffix "_previously_changed?", "_changed?", parameters: "**options"
      attribute_method_suffix "_change", "_will_change!", "_was", parameters: false
      attribute_method_suffix "_previous_change", "_previously_was", parameters: false
      attribute_method_affix prefix: "restore_", suffix: "!", parameters: false
      attribute_method_affix prefix: "clear_", suffix: "_change", parameters: false
    end

    def initialize_dup(other) # :nodoc:
      super
      if self.class.respond_to?(:_default_attributes)
        @attributes = self.class._default_attributes.map do |attr|
          attr.with_value_from_user(@attributes.fetch_value(attr.name))
        end
      end
      @mutations_from_database = nil
    end

    def as_json(options = {}) # :nodoc:
      options[:except] = [*options[:except], "mutations_from_database", "mutations_before_last_save"]
      super(options)
    end

    # Clears dirty data and moves +changes+ to +previous_changes+ and
    # +mutations_from_database+ to +mutations_before_last_save+ respectively.
    def changes_applied
      unless defined?(@attributes)
        mutations_from_database.finalize_changes
      end
      @mutations_before_last_save = mutations_from_database
      forget_attribute_assignments
      @mutations_from_database = nil
    end

    # Returns +true+ if any of the attributes has unsaved changes, +false+ otherwise.
    #
    #   person.changed? # => false
    #   person.name = 'bob'
    #   person.changed? # => true
    def changed?
      mutations_from_database.any_changes?
    end

    # Returns an array with the name of the attributes with unsaved changes.
    #
    #   person.changed # => []
    #   person.name = 'bob'
    #   person.changed # => ["name"]
    def changed
      mutations_from_database.changed_attribute_names
    end

    # Dispatch target for <tt>*_changed?</tt> attribute methods.
    def attribute_changed?(attr_name, **options) # :nodoc:
      mutations_from_database.changed?(attr_name.to_s, **options)
    end

    # Dispatch target for <tt>*_was</tt> attribute methods.
    def attribute_was(attr_name) # :nodoc:
      mutations_from_database.original_value(attr_name.to_s)
    end

    # Dispatch target for <tt>*_previously_changed?</tt> attribute methods.
    def attribute_previously_changed?(attr_name, **options) # :nodoc:
      mutations_before_last_save.changed?(attr_name.to_s, **options)
    end

    # Dispatch target for <tt>*_previously_was</tt> attribute methods.
    def attribute_previously_was(attr_name) # :nodoc:
      mutations_before_last_save.original_value(attr_name.to_s)
    end

    # Restore all previous data of the provided attributes.
    def restore_attributes(attr_names = changed)
      attr_names.each { |attr_name| restore_attribute!(attr_name) }
    end

    # Clears all dirty data: current changes and previous changes.
    def clear_changes_information
      @mutations_before_last_save = nil
      forget_attribute_assignments
      @mutations_from_database = nil
    end

    def clear_attribute_changes(attr_names)
      attr_names.each do |attr_name|
        clear_attribute_change(attr_name)
      end
    end

    # Returns a hash of the attributes with unsaved changes indicating their original
    # values like <tt>attr => original value</tt>.
    #
    #   person.name # => "bob"
    #   person.name = 'robert'
    #   person.changed_attributes # => {"name" => "bob"}
    def changed_attributes
      mutations_from_database.changed_values
    end

    # Returns a hash of changed attributes indicating their original
    # and new values like <tt>attr => [original value, new value]</tt>.
    #
    #   person.changes # => {}
    #   person.name = 'bob'
    #   person.changes # => { "name" => ["bill", "bob"] }
    def changes
      mutations_from_database.changes
    end

    # Returns a hash of attributes that were changed before the model was saved.
    #
    #   person.name # => "bob"
    #   person.name = 'robert'
    #   person.save
    #   person.previous_changes # => {"name" => ["bob", "robert"]}
    def previous_changes
      mutations_before_last_save.changes
    end

    def attribute_changed_in_place?(attr_name) # :nodoc:
      mutations_from_database.changed_in_place?(attr_name.to_s)
    end

    private
      def clear_attribute_change(attr_name)
        mutations_from_database.forget_change(attr_name.to_s)
      end

      def mutations_from_database
        @mutations_from_database ||= if defined?(@attributes)
          ActiveModel::AttributeMutationTracker.new(@attributes)
        else
          ActiveModel::ForcedMutationTracker.new(self)
        end
      end

      def forget_attribute_assignments
        @attributes = @attributes.map(&:forgetting_assignment) if defined?(@attributes)
      end

      def mutations_before_last_save
        @mutations_before_last_save ||= ActiveModel::NullMutationTracker.instance
      end

      # Dispatch target for <tt>*_change</tt> attribute methods.
      def attribute_change(attr_name)
        mutations_from_database.change_to_attribute(attr_name.to_s)
      end

      # Dispatch target for <tt>*_previous_change</tt> attribute methods.
      def attribute_previous_change(attr_name)
        mutations_before_last_save.change_to_attribute(attr_name.to_s)
      end

      # Dispatch target for <tt>*_will_change!</tt> attribute methods.
      def attribute_will_change!(attr_name)
        mutations_from_database.force_change(attr_name.to_s)
      end

      # Dispatch target for <tt>restore_*!</tt> attribute methods.
      def restore_attribute!(attr_name)
        attr_name = attr_name.to_s
        if attribute_changed?(attr_name)
          __send__("#{attr_name}=", attribute_was(attr_name))
          clear_attribute_change(attr_name)
        end
      end
  end
end

dirty_test.rb

# frozen_string_literal: true

require "cases/helper"
require "active_support/json"

class DirtyTest < ActiveModel::TestCase
  class DirtyModel
    include ActiveModel::Dirty
    define_attribute_methods :name, :color, :size, :status

    def initialize
      @name = nil
      @color = nil
      @size = nil
      @status = "initialized"
    end

    attr_reader :name, :color, :size, :status

    def name=(val)
      name_will_change!
      @name = val
    end

    def color=(val)
      color_will_change! unless val == @color
      @color = val
    end

    def size=(val)
      attribute_will_change!(:size) unless val == @size
      @size = val
    end

    def status=(val)
      status_will_change! unless val == @status
      @status = val
    end

    def save
      changes_applied
    end
  end

  setup do
    @model = DirtyModel.new
  end

  test "setting attribute will result in change" do
    assert_not_predicate @model, :changed?
    assert_not_predicate @model, :name_changed?
    @model.name = "Ringo"
    assert_predicate @model, :changed?
    assert_predicate @model, :name_changed?
  end

  test "list of changed attribute keys" do
    assert_equal [], @model.changed
    @model.name = "Paul"
    assert_equal ["name"], @model.changed
  end

  test "changes to attribute values" do
    assert_not @model.changes["name"]
    @model.name = "John"
    assert_equal [nil, "John"], @model.changes["name"]
  end

  test "checking if an attribute has changed to a particular value" do
    @model.name = "Ringo"
    assert @model.name_changed?(from: nil, to: "Ringo")
    assert_not @model.name_changed?(from: "Pete", to: "Ringo")
    assert @model.name_changed?(to: "Ringo")
    assert_not @model.name_changed?(to: "Pete")
    assert @model.name_changed?(from: nil)
    assert_not @model.name_changed?(from: "Pete")
  end

  test "changes accessible through both strings and symbols" do
    @model.name = "David"
    assert_not_nil @model.changes[:name]
    assert_not_nil @model.changes["name"]
  end

  test "be consistent with symbols arguments after the changes are applied" do
    @model.name = "David"
    assert @model.attribute_changed?(:name)
    @model.save
    @model.name = "Rafael"
    assert @model.attribute_changed?(:name)
  end

  test "attribute mutation" do
    @model.instance_variable_set("@name", +"Yam")
    assert_not_predicate @model, :name_changed?
    @model.name.replace("Hadad")
    assert_not_predicate @model, :name_changed?
    @model.name_will_change!
    @model.name.replace("Baal")
    assert_predicate @model, :name_changed?
  end

  test "resetting attribute" do
    @model.name = "Bob"
    @model.restore_name!
    assert_nil @model.name
    assert_not_predicate @model, :name_changed?
  end

  test "setting color to same value should not result in change being recorded" do
    @model.color = "red"
    assert_predicate @model, :color_changed?
    @model.save
    assert_not_predicate @model, :color_changed?
    assert_not_predicate @model, :changed?
    @model.color = "red"
    assert_not_predicate @model, :color_changed?
    assert_not_predicate @model, :changed?
  end

  test "saving should reset model's changed status" do
    @model.name = "Alf"
    assert_predicate @model, :changed?
    @model.save
    assert_not_predicate @model, :changed?
    assert_not_predicate @model, :name_changed?
  end

  test "saving should preserve previous changes" do
    @model.name = "Jericho Cane"
    @model.status = "waiting"
    @model.save
    assert_equal [nil, "Jericho Cane"], @model.previous_changes["name"]
    assert_equal ["initialized", "waiting"], @model.previous_changes["status"]
  end

  test "setting new attributes should not affect previous changes" do
    @model.name = "Jericho Cane"
    @model.status = "waiting"
    @model.save
    @model.name = "DudeFella ManGuy"
    @model.status = "finished"
    assert_equal [nil, "Jericho Cane"], @model.name_previous_change
    assert_equal ["initialized", "waiting"], @model.previous_changes["status"]
  end

  test "saving should preserve model's previous changed status" do
    @model.name = "Jericho Cane"
    @model.save
    assert_predicate @model, :name_previously_changed?
  end

  test "checking if an attribute was previously changed to a particular value" do
    @model.name = "Ringo"
    @model.save
    assert @model.name_previously_changed?(from: nil, to: "Ringo")
    assert_not @model.name_previously_changed?(from: "Pete", to: "Ringo")
    assert @model.name_previously_changed?(to: "Ringo")
    assert_not @model.name_previously_changed?(to: "Pete")
    assert @model.name_previously_changed?(from: nil)
    assert_not @model.name_previously_changed?(from: "Pete")
  end

  test "previous value is preserved when changed after save" do
    assert_equal({}, @model.changed_attributes)
    @model.name = "Paul"
    @model.status = "waiting"
    assert_equal({ "name" => nil, "status" => "initialized" }, @model.changed_attributes)

    @model.save

    @model.name = "John"
    @model.status = "finished"
    assert_equal({ "name" => "Paul", "status" => "waiting" }, @model.changed_attributes)
  end

  test "changing the same attribute multiple times retains the correct original value" do
    @model.name = "Otto"
    @model.status = "waiting"
    @model.save
    @model.name = "DudeFella ManGuy"
    @model.name = "Mr. Manfredgensonton"
    @model.status = "processing"
    @model.status = "finished"
    assert_equal ["Otto", "Mr. Manfredgensonton"], @model.name_change
    assert_equal ["waiting", "finished"], @model.status_change
    assert_equal @model.name_was, "Otto"
  end

  test "using attribute_will_change! with a symbol" do
    @model.size = 1
    assert_predicate @model, :size_changed?
  end

  test "clear_changes_information should reset all changes" do
    @model.name = "Dmitry"
    @model.name_changed?
    @model.save
    @model.name = "Bob"

    assert_equal [nil, "Dmitry"], @model.previous_changes["name"]
    assert_equal "Dmitry", @model.changed_attributes["name"]

    @model.clear_changes_information

    assert_equal ActiveSupport::HashWithIndifferentAccess.new, @model.previous_changes
    assert_equal ActiveSupport::HashWithIndifferentAccess.new, @model.changed_attributes
  end

  test "restore_attributes should restore all previous data" do
    @model.name = "Dmitry"
    @model.color = "Red"
    @model.save
    @model.name = "Bob"
    @model.color = "White"

    @model.restore_attributes

    assert_not_predicate @model, :changed?
    assert_equal "Dmitry", @model.name
    assert_equal "Red", @model.color
  end

  test "restore_attributes can restore only some attributes" do
    @model.name = "Dmitry"
    @model.color = "Red"
    @model.save
    @model.name = "Bob"
    @model.color = "White"

    @model.restore_attributes(["name"])

    assert_predicate @model, :changed?
    assert_equal "Dmitry", @model.name
    assert_equal "White", @model.color
  end

  test "model can be dup-ed without Attributes" do
    assert @model.dup
  end

  test "to_json should work on model" do
    @model.name = "Dmitry"
    assert_equal "{\"name\":\"Dmitry\",\"color\":null,\"size\":null,\"status\":\"initialized\"}", @model.to_json
  end

  test "to_json should work on model with :except string option" do
    @model.name = "Dmitry"
    assert_equal "{\"color\":null,\"size\":null,\"status\":\"initialized\"}", @model.to_json(except: "name")
  end

  test "to_json should work on model with :except array option" do
    @model.name = "Dmitry"
    assert_equal "{\"color\":null,\"size\":null,\"status\":\"initialized\"}", @model.to_json(except: ["name"])
  end

  test "to_json should work on model after save" do
    @model.name = "Dmitry"
    @model.save
    assert_equal "{\"name\":\"Dmitry\",\"color\":null,\"size\":null,\"status\":\"initialized\"}", @model.to_json
  end
end

email_validator.rb

# frozen_string_literal: true

require "validators/email_validator"

module Namespace
  class EmailValidator < ::EmailValidator
  end
end

error.rb

# frozen_string_literal: true

require "active_support/core_ext/class/attribute"

module ActiveModel
  # == Active \Model \Error
  #
  # Represents one single error
  class Error
    CALLBACKS_OPTIONS = [:if, :unless, :on, :allow_nil, :allow_blank, :strict]
    MESSAGE_OPTIONS = [:message]

    class_attribute :i18n_customize_full_message, default: false

    def self.full_message(attribute, message, base) # :nodoc:
      return message if attribute == :base

      base_class = base.class
      attribute = attribute.to_s

      if i18n_customize_full_message && base_class.respond_to?(:i18n_scope)
        attribute = attribute.remove(/\[\d+\]/)
        parts = attribute.split(".")
        attribute_name = parts.pop
        namespace = parts.join("/") unless parts.empty?
        attributes_scope = "#{base_class.i18n_scope}.errors.models"

        if namespace
          defaults = base_class.lookup_ancestors.map do |klass|
            [
              :"#{attributes_scope}.#{klass.model_name.i18n_key}/#{namespace}.attributes.#{attribute_name}.format",
              :"#{attributes_scope}.#{klass.model_name.i18n_key}/#{namespace}.format",
            ]
          end
        else
          defaults = base_class.lookup_ancestors.map do |klass|
            [
              :"#{attributes_scope}.#{klass.model_name.i18n_key}.attributes.#{attribute_name}.format",
              :"#{attributes_scope}.#{klass.model_name.i18n_key}.format",
            ]
          end
        end

        defaults.flatten!
      else
        defaults = []
      end

      defaults << :"errors.format"
      defaults << "%{attribute} %{message}"

      attr_name = attribute.tr(".", "_").humanize
      attr_name = base_class.human_attribute_name(attribute, {
        default: attr_name,
        base: base,
      })

      I18n.t(defaults.shift,
        default:  defaults,
        attribute: attr_name,
        message:   message)
    end

    def self.generate_message(attribute, type, base, options) # :nodoc:
      type = options.delete(:message) if options[:message].is_a?(Symbol)
      value = (attribute != :base ? base.read_attribute_for_validation(attribute) : nil)

      options = {
        model: base.model_name.human,
        attribute: base.class.human_attribute_name(attribute, { base: base }),
        value: value,
        object: base
      }.merge!(options)

      if base.class.respond_to?(:i18n_scope)
        i18n_scope = base.class.i18n_scope.to_s
        attribute = attribute.to_s.remove(/\[\d+\]/)

        defaults = base.class.lookup_ancestors.flat_map do |klass|
          [ :"#{i18n_scope}.errors.models.#{klass.model_name.i18n_key}.attributes.#{attribute}.#{type}",
            :"#{i18n_scope}.errors.models.#{klass.model_name.i18n_key}.#{type}" ]
        end
        defaults << :"#{i18n_scope}.errors.messages.#{type}"

        catch(:exception) do
          translation = I18n.translate(defaults.first, **options.merge(default: defaults.drop(1), throw: true))
          return translation unless translation.nil?
        end unless options[:message]
      else
        defaults = []
      end

      defaults << :"errors.attributes.#{attribute}.#{type}"
      defaults << :"errors.messages.#{type}"

      key = defaults.shift
      defaults = options.delete(:message) if options[:message]
      options[:default] = defaults

      I18n.translate(key, **options)
    end

    def initialize(base, attribute, type = :invalid, **options)
      @base = base
      @attribute = attribute
      @raw_type = type
      @type = type || :invalid
      @options = options
    end

    def initialize_dup(other) # :nodoc:
      @attribute = @attribute.dup
      @raw_type = @raw_type.dup
      @type = @type.dup
      @options = @options.deep_dup
    end

    # The object which the error belongs to
    attr_reader :base
    # The attribute of +base+ which the error belongs to
    attr_reader :attribute
    # The type of error, defaults to +:invalid+ unless specified
    attr_reader :type
    # The raw value provided as the second parameter when calling +errors#add+
    attr_reader :raw_type
    # The options provided when calling +errors#add+
    attr_reader :options

    # Returns the error message.
    #
    #   error = ActiveModel::Error.new(person, :name, :too_short, count: 5)
    #   error.message
    #   # => "is too short (minimum is 5 characters)"
    def message
      case raw_type
      when Symbol
        self.class.generate_message(attribute, raw_type, @base, options.except(*CALLBACKS_OPTIONS))
      else
        raw_type
      end
    end

    # Returns the error details.
    #
    #   error = ActiveModel::Error.new(person, :name, :too_short, count: 5)
    #   error.details
    #   # => { error: :too_short, count: 5 }
    def details
      { error: raw_type }.merge(options.except(*CALLBACKS_OPTIONS + MESSAGE_OPTIONS))
    end
    alias_method :detail, :details

    # Returns the full error message.
    #
    #   error = ActiveModel::Error.new(person, :name, :too_short, count: 5)
    #   error.full_message
    #   # => "Name is too short (minimum is 5 characters)"
    def full_message
      self.class.full_message(attribute, message, @base)
    end

    # See if error matches provided +attribute+, +type+, and +options+.
    #
    # Omitted params are not checked for a match.
    def match?(attribute, type = nil, **options)
      if @attribute != attribute || (type && @type != type)
        return false
      end

      options.each do |key, value|
        if @options[key] != value
          return false
        end
      end

      true
    end

    # See if error matches provided +attribute+, +type+, and +options+ exactly.
    #
    # All params must be equal to Error's own attributes to be considered a
    # strict match.
    def strict_match?(attribute, type, **options)
      return false unless match?(attribute, type)

      options == @options.except(*CALLBACKS_OPTIONS + MESSAGE_OPTIONS)
    end

    def ==(other) # :nodoc:
      other.is_a?(self.class) && attributes_for_hash == other.attributes_for_hash
    end
    alias eql? ==

    def hash # :nodoc:
      attributes_for_hash.hash
    end

    def inspect # :nodoc:
      "#<#{self.class.name} attribute=#{@attribute}, type=#{@type}, options=#{@options.inspect}>"
    end

    protected
      def attributes_for_hash
        [@base, @attribute, @raw_type, @options.except(*CALLBACKS_OPTIONS)]
      end
  end
end

error_test.rb

# frozen_string_literal: true

require "cases/helper"
require "active_model/error"

class ErrorTest < ActiveModel::TestCase
  class Person
    extend ActiveModel::Naming
    def initialize
      @errors = ActiveModel::Errors.new(self)
    end

    attr_accessor :name, :age
    attr_reader   :errors

    def read_attribute_for_validation(attr)
      send(attr)
    end

    def self.human_attribute_name(attr, options = {})
      attr
    end

    def self.lookup_ancestors
      [self]
    end
  end

  class Manager < Person
    def read_attribute_for_validation(attr)
      try(attr)
    end

    def self.i18n_scope
      :activemodel
    end
  end

  def test_initialize
    base = Person.new
    error = ActiveModel::Error.new(base, :name, :too_long, foo: :bar)
    assert_equal base, error.base
    assert_equal :name, error.attribute
    assert_equal :too_long, error.type
    assert_equal({ foo: :bar }, error.options)
  end

  test "initialize without type" do
    error = ActiveModel::Error.new(Person.new, :name)
    assert_equal :invalid, error.type
    assert_equal({}, error.options)
  end

  test "initialize without type but with options" do
    options = { message: "bar" }
    error = ActiveModel::Error.new(Person.new, :name, **options)
    assert_equal(options, error.options)
  end

  # match?

  test "match? handles mixed condition" do
    subject = ActiveModel::Error.new(Person.new, :mineral, :not_enough, count: 2)
    assert_not subject.match?(:mineral, :too_coarse)
    assert subject.match?(:mineral, :not_enough)
    assert subject.match?(:mineral, :not_enough, count: 2)
    assert_not subject.match?(:mineral, :not_enough, count: 1)
  end

  test "match? handles attribute match" do
    subject = ActiveModel::Error.new(Person.new, :mineral, :not_enough, count: 2)
    assert_not subject.match?(:foo)
    assert subject.match?(:mineral)
  end

  test "match? handles error type match" do
    subject = ActiveModel::Error.new(Person.new, :mineral, :not_enough, count: 2)
    assert_not subject.match?(:mineral, :too_coarse)
    assert subject.match?(:mineral, :not_enough)
  end

  test "match? handles extra options match" do
    subject = ActiveModel::Error.new(Person.new, :mineral, :not_enough, count: 2)
    assert_not subject.match?(:mineral, :not_enough, count: 1)
    assert subject.match?(:mineral, :not_enough, count: 2)
  end

  # message

  test "message with type as a symbol" do
    error = ActiveModel::Error.new(Person.new, :name, :blank)
    assert_equal "can't be blank", error.message
  end

  test "message with custom interpolation" do
    subject = ActiveModel::Error.new(Person.new, :name, :inclusion, message: "custom message %{value}", value: "name")
    assert_equal "custom message name", subject.message
  end

  test "message returns plural interpolation" do
    subject = ActiveModel::Error.new(Person.new, :name, :too_long, count: 10)
    assert_equal "is too long (maximum is 10 characters)", subject.message
  end

  test "message returns singular interpolation" do
    subject = ActiveModel::Error.new(Person.new, :name, :too_long, count: 1)
    assert_equal "is too long (maximum is 1 character)", subject.message
  end

  test "message returns count interpolation" do
    subject = ActiveModel::Error.new(Person.new, :name, :too_long, message: "custom message %{count}", count: 10)
    assert_equal "custom message 10", subject.message
  end

  test "message handles lambda in messages and option values, and i18n interpolation" do
    subject = ActiveModel::Error.new(Person.new, :name, :invalid,
      foo: "foo",
      bar: "bar",
      baz: Proc.new { "baz" },
      message: Proc.new { |model, options|
        "%{attribute} %{foo} #{options[:bar]} %{baz}"
      }
    )
    assert_equal "name foo bar baz", subject.message
  end

  test "generate_message works without i18n_scope" do
    person = Person.new
    error = ActiveModel::Error.new(person, :name, :blank)
    assert_not_respond_to Person, :i18n_scope
    assert_nothing_raised {
      error.message
    }
  end

  test "message with type as custom message" do
    error = ActiveModel::Error.new(Person.new, :name, message: "cannot be blank")
    assert_equal "cannot be blank", error.message
  end

  test "message with options[:message] as custom message" do
    error = ActiveModel::Error.new(Person.new, :name, :blank, message: "cannot be blank")
    assert_equal "cannot be blank", error.message
  end

  test "message renders lazily using current locale" do
    error = nil

    I18n.backend.store_translations(:pl, errors: { messages: { invalid: "jest nieprawidłowe" } })

    I18n.with_locale(:en) { error = ActiveModel::Error.new(Person.new, :name, :invalid) }
    I18n.with_locale(:pl) {
      assert_equal "jest nieprawidłowe", error.message
    }
  end

  test "message with type as a symbol and indexed attribute can lookup without index in attribute key" do
    I18n.backend.store_translations(:en, activemodel: { errors: { models: { 'error_test/manager': {
      attributes: { reports: { name: { presence: "must be present" } } } } } } })

    error = ActiveModel::Error.new(Manager.new, :'reports[123].name', :presence)

    assert_equal "must be present", error.message
  end

  test "message uses current locale" do
    I18n.backend.store_translations(:en, errors: { messages: { inadequate: "Inadequate %{attribute} found!" } })
    error = ActiveModel::Error.new(Person.new, :name, :inadequate)
    assert_equal "Inadequate name found!", error.message
  end

  # full_message

  test "full_message returns the given message when attribute is :base" do
    error = ActiveModel::Error.new(Person.new, :base, message: "press the button")
    assert_equal "press the button", error.full_message
  end

  test "full_message returns the given message with the attribute name included" do
    error = ActiveModel::Error.new(Person.new, :name, :blank)
    assert_equal "name can't be blank", error.full_message
  end

  test "full_message uses default format" do
    error = ActiveModel::Error.new(Person.new, :name, message: "can't be blank")

    # Use a locale without errors.format
    I18n.with_locale(:unknown) {
      assert_equal "name can't be blank", error.full_message
    }
  end

  test "equality by base attribute, type and options" do
    person = Person.new

    e1 = ActiveModel::Error.new(person, :name, foo: :bar)
    e2 = ActiveModel::Error.new(person, :name, foo: :bar)
    e2.instance_variable_set(:@_humanized_attribute, "Name")

    assert_equal(e1, e2)
  end

  test "inequality" do
    person = Person.new
    error = ActiveModel::Error.new(person, :name, foo: :bar)

    assert error != ActiveModel::Error.new(person, :name, foo: :baz)
    assert error != ActiveModel::Error.new(person, :name)
    assert error != ActiveModel::Error.new(person, :title, foo: :bar)
    assert error != ActiveModel::Error.new(Person.new, :name, foo: :bar)
  end

  test "comparing against different class would not raise error" do
    person = Person.new
    error = ActiveModel::Error.new(person, :name, foo: :bar)

    assert_not_equal error, person
  end

  # details

  test "details which ignores callback and message options" do
    person = Person.new
    error = ActiveModel::Error.new(
      person,
      :name,
      :too_short,
      foo: :bar,
      if: :foo,
      unless: :bar,
      on: :baz,
      allow_nil: false,
      allow_blank: false,
      strict: true,
      message: "message"
    )

    assert_equal(
      error.details,
      { error: :too_short, foo: :bar }
    )
  end

  test "details which has no raw_type" do
    person = Person.new
    error = ActiveModel::Error.new(person, :name, foo: :bar)

    assert_equal(error.details, { error: :invalid, foo: :bar })
  end
end

errors.rb

# frozen_string_literal: true

require "active_support/core_ext/array/conversions"
require "active_support/core_ext/string/inflections"
require "active_support/core_ext/object/deep_dup"
require "active_support/core_ext/string/filters"
require "active_model/error"
require "active_model/nested_error"
require "forwardable"

module ActiveModel
  # == Active \Model \Errors
  #
  # Provides error related functionalities you can include in your object
  # for handling error messages and interacting with Action View helpers.
  #
  # A minimal implementation could be:
  #
  #   class Person
  #     # Required dependency for ActiveModel::Errors
  #     extend ActiveModel::Naming
  #
  #     def initialize
  #       @errors = ActiveModel::Errors.new(self)
  #     end
  #
  #     attr_accessor :name
  #     attr_reader   :errors
  #
  #     def validate!
  #       errors.add(:name, :blank, message: "cannot be nil") if name.nil?
  #     end
  #
  #     # The following methods are needed to be minimally implemented
  #
  #     def read_attribute_for_validation(attr)
  #       send(attr)
  #     end
  #
  #     def self.human_attribute_name(attr, options = {})
  #       attr
  #     end
  #
  #     def self.lookup_ancestors
  #       [self]
  #     end
  #   end
  #
  # The last three methods are required in your object for +Errors+ to be
  # able to generate error messages correctly and also handle multiple
  # languages. Of course, if you extend your object with ActiveModel::Translation
  # you will not need to implement the last two. Likewise, using
  # ActiveModel::Validations will handle the validation related methods
  # for you.
  #
  # The above allows you to do:
  #
  #   person = Person.new
  #   person.validate!            # => ["cannot be nil"]
  #   person.errors.full_messages # => ["name cannot be nil"]
  #   # etc..
  class Errors
    include Enumerable

    extend Forwardable

    # :method: each
    #
    # :call-seq: each(&block)
    #
    # Iterates through each error object.
    #
    #   person.errors.add(:name, :too_short, count: 2)
    #   person.errors.each do |error|
    #     # Will yield <#ActiveModel::Error attribute=name, type=too_short,
    #                                       options={:count=>3}>
    #   end
    def_delegators :@errors, :each, :clear, :empty?, :size, :uniq!

    # The actual array of +Error+ objects
    # This method is aliased to <tt>objects</tt>.
    attr_reader :errors
    alias :objects :errors

    # Pass in the instance of the object that is using the errors object.
    #
    #   class Person
    #     def initialize
    #       @errors = ActiveModel::Errors.new(self)
    #     end
    #   end
    def initialize(base)
      @base = base
      @errors = []
    end

    def initialize_dup(other) # :nodoc:
      @errors = other.errors.deep_dup
      super
    end

    # Copies the errors from <tt>other</tt>.
    # For copying errors but keep <tt>@base</tt> as is.
    #
    # ==== Parameters
    #
    # * +other+ - The ActiveModel::Errors instance.
    #
    # ==== Examples
    #
    #   person.errors.copy!(other)
    #
    def copy!(other) # :nodoc:
      @errors = other.errors.deep_dup
      @errors.each { |error|
        error.instance_variable_set(:@base, @base)
      }
    end

    # Imports one error.
    # Imported errors are wrapped as a NestedError,
    # providing access to original error object.
    # If attribute or type needs to be overridden, use +override_options+.
    #
    # ==== Options
    #
    # * +:attribute+ - Override the attribute the error belongs to.
    # * +:type+ - Override type of the error.
    def import(error, override_options = {})
      [:attribute, :type].each do |key|
        if override_options.key?(key)
          override_options[key] = override_options[key].to_sym
        end
      end
      @errors.append(NestedError.new(@base, error, override_options))
    end

    # Merges the errors from <tt>other</tt>,
    # each Error wrapped as NestedError.
    #
    # ==== Parameters
    #
    # * +other+ - The ActiveModel::Errors instance.
    #
    # ==== Examples
    #
    #   person.errors.merge!(other)
    #
    def merge!(other)
      return errors if equal?(other)

      other.errors.each { |error|
        import(error)
      }
    end

    # Search for errors matching +attribute+, +type+, or +options+.
    #
    # Only supplied params will be matched.
    #
    #   person.errors.where(:name) # => all name errors.
    #   person.errors.where(:name, :too_short) # => all name errors being too short
    #   person.errors.where(:name, :too_short, minimum: 2) # => all name errors being too short and minimum is 2
    def where(attribute, type = nil, **options)
      attribute, type, options = normalize_arguments(attribute, type, **options)
      @errors.select { |error|
        error.match?(attribute, type, **options)
      }
    end

    # Returns +true+ if the error messages include an error for the given key
    # +attribute+, +false+ otherwise.
    #
    #   person.errors.messages        # => {:name=>["cannot be nil"]}
    #   person.errors.include?(:name) # => true
    #   person.errors.include?(:age)  # => false
    def include?(attribute)
      @errors.any? { |error|
        error.match?(attribute.to_sym)
      }
    end
    alias :has_key? :include?
    alias :key? :include?

    # Delete messages for +key+. Returns the deleted messages.
    #
    #   person.errors[:name]        # => ["cannot be nil"]
    #   person.errors.delete(:name) # => ["cannot be nil"]
    #   person.errors[:name]        # => []
    def delete(attribute, type = nil, **options)
      attribute, type, options = normalize_arguments(attribute, type, **options)
      matches = where(attribute, type, **options)
      matches.each do |error|
        @errors.delete(error)
      end
      matches.map(&:message).presence
    end

    # When passed a symbol or a name of a method, returns an array of errors
    # for the method.
    #
    #   person.errors[:name]  # => ["cannot be nil"]
    #   person.errors['name'] # => ["cannot be nil"]
    def [](attribute)
      messages_for(attribute)
    end

    # Returns all error attribute names
    #
    #   person.errors.messages        # => {:name=>["cannot be nil", "must be specified"]}
    #   person.errors.attribute_names # => [:name]
    def attribute_names
      @errors.map(&:attribute).uniq.freeze
    end

    # Returns a Hash that can be used as the JSON representation for this
    # object. You can pass the <tt>:full_messages</tt> option. This determines
    # if the json object should contain full messages or not (false by default).
    #
    #   person.errors.as_json                      # => {:name=>["cannot be nil"]}
    #   person.errors.as_json(full_messages: true) # => {:name=>["name cannot be nil"]}
    def as_json(options = nil)
      to_hash(options && options[:full_messages])
    end

    # Returns a Hash of attributes with their error messages. If +full_messages+
    # is +true+, it will contain full messages (see +full_message+).
    #
    #   person.errors.to_hash       # => {:name=>["cannot be nil"]}
    #   person.errors.to_hash(true) # => {:name=>["name cannot be nil"]}
    def to_hash(full_messages = false)
      message_method = full_messages ? :full_message : :message
      group_by_attribute.transform_values do |errors|
        errors.map(&message_method)
      end
    end

    undef :to_h

    EMPTY_ARRAY = [].freeze # :nodoc:

    # Returns a Hash of attributes with an array of their error messages.
    def messages
      hash = to_hash
      hash.default = EMPTY_ARRAY
      hash.freeze
      hash
    end

    # Returns a Hash of attributes with an array of their error details.
    def details
      hash = group_by_attribute.transform_values do |errors|
        errors.map(&:details)
      end
      hash.default = EMPTY_ARRAY
      hash.freeze
      hash
    end

    # Returns a Hash of attributes with an array of their Error objects.
    #
    #   person.errors.group_by_attribute
    #   # => {:name=>[<#ActiveModel::Error>, <#ActiveModel::Error>]}
    def group_by_attribute
      @errors.group_by(&:attribute)
    end

    # Adds a new error of +type+ on +attribute+.
    # More than one error can be added to the same +attribute+.
    # If no +type+ is supplied, <tt>:invalid</tt> is assumed.
    #
    #   person.errors.add(:name)
    #   # Adds <#ActiveModel::Error attribute=name, type=invalid>
    #   person.errors.add(:name, :not_implemented, message: "must be implemented")
    #   # Adds <#ActiveModel::Error attribute=name, type=not_implemented,
    #                               options={:message=>"must be implemented"}>
    #
    #   person.errors.messages
    #   # => {:name=>["is invalid", "must be implemented"]}
    #
    # If +type+ is a string, it will be used as error message.
    #
    # If +type+ is a symbol, it will be translated using the appropriate
    # scope (see +generate_message+).
    #
    #   person.errors.add(:name, :blank)
    #   person.errors.messages
    #   # => {:name=>["can't be blank"]}
    #
    #   person.errors.add(:name, :too_long, { count: 25 })
    #   person.errors.messages
    #   # => ["is too long (maximum is 25 characters)"]
    #
    # If +type+ is a proc, it will be called, allowing for things like
    # <tt>Time.now</tt> to be used within an error.
    #
    # If the <tt>:strict</tt> option is set to +true+, it will raise
    # ActiveModel::StrictValidationFailed instead of adding the error.
    # <tt>:strict</tt> option can also be set to any other exception.
    #
    #   person.errors.add(:name, :invalid, strict: true)
    #   # => ActiveModel::StrictValidationFailed: Name is invalid
    #   person.errors.add(:name, :invalid, strict: NameIsInvalid)
    #   # => NameIsInvalid: Name is invalid
    #
    #   person.errors.messages # => {}
    #
    # +attribute+ should be set to <tt>:base</tt> if the error is not
    # directly associated with a single attribute.
    #
    #   person.errors.add(:base, :name_or_email_blank,
    #     message: "either name or email must be present")
    #   person.errors.messages
    #   # => {:base=>["either name or email must be present"]}
    #   person.errors.details
    #   # => {:base=>[{error: :name_or_email_blank}]}
    def add(attribute, type = :invalid, **options)
      attribute, type, options = normalize_arguments(attribute, type, **options)
      error = Error.new(@base, attribute, type, **options)

      if exception = options[:strict]
        exception = ActiveModel::StrictValidationFailed if exception == true
        raise exception, error.full_message
      end

      @errors.append(error)

      error
    end

    # Returns +true+ if an error matches provided +attribute+ and +type+,
    # or +false+ otherwise. +type+ is treated the same as for +add+.
    #
    #   person.errors.add :name, :blank
    #   person.errors.added? :name, :blank           # => true
    #   person.errors.added? :name, "can't be blank" # => true
    #
    # If the error requires options, then it returns +true+ with
    # the correct options, or +false+ with incorrect or missing options.
    #
    #   person.errors.add :name, :too_long, { count: 25 }
    #   person.errors.added? :name, :too_long, count: 25                     # => true
    #   person.errors.added? :name, "is too long (maximum is 25 characters)" # => true
    #   person.errors.added? :name, :too_long, count: 24                     # => false
    #   person.errors.added? :name, :too_long                                # => false
    #   person.errors.added? :name, "is too long"                            # => false
    def added?(attribute, type = :invalid, options = {})
      attribute, type, options = normalize_arguments(attribute, type, **options)

      if type.is_a? Symbol
        @errors.any? { |error|
          error.strict_match?(attribute, type, **options)
        }
      else
        messages_for(attribute).include?(type)
      end
    end

    # Returns +true+ if an error on the attribute with the given type is
    # present, or +false+ otherwise. +type+ is treated the same as for +add+.
    #
    #   person.errors.add :age
    #   person.errors.add :name, :too_long, { count: 25 }
    #   person.errors.of_kind? :age                                            # => true
    #   person.errors.of_kind? :name                                           # => false
    #   person.errors.of_kind? :name, :too_long                                # => true
    #   person.errors.of_kind? :name, "is too long (maximum is 25 characters)" # => true
    #   person.errors.of_kind? :name, :not_too_long                            # => false
    #   person.errors.of_kind? :name, "is too long"                            # => false
    def of_kind?(attribute, type = :invalid)
      attribute, type = normalize_arguments(attribute, type)

      if type.is_a? Symbol
        !where(attribute, type).empty?
      else
        messages_for(attribute).include?(type)
      end
    end

    # Returns all the full error messages in an array.
    #
    #   class Person
    #     validates_presence_of :name, :address, :email
    #     validates_length_of :name, in: 5..30
    #   end
    #
    #   person = Person.create(address: '123 First St.')
    #   person.errors.full_messages
    #   # => ["Name is too short (minimum is 5 characters)", "Name can't be blank", "Email can't be blank"]
    def full_messages
      @errors.map(&:full_message)
    end
    alias :to_a :full_messages

    # Returns all the full error messages for a given attribute in an array.
    #
    #   class Person
    #     validates_presence_of :name, :email
    #     validates_length_of :name, in: 5..30
    #   end
    #
    #   person = Person.create()
    #   person.errors.full_messages_for(:name)
    #   # => ["Name is too short (minimum is 5 characters)", "Name can't be blank"]
    def full_messages_for(attribute)
      where(attribute).map(&:full_message).freeze
    end

    # Returns all the error messages for a given attribute in an array.
    #
    #   class Person
    #     validates_presence_of :name, :email
    #     validates_length_of :name, in: 5..30
    #   end
    #
    #   person = Person.create()
    #   person.errors.messages_for(:name)
    #   # => ["is too short (minimum is 5 characters)", "can't be blank"]
    def messages_for(attribute)
      where(attribute).map(&:message)
    end

    # Returns a full message for a given attribute.
    #
    #   person.errors.full_message(:name, 'is invalid') # => "Name is invalid"
    def full_message(attribute, message)
      Error.full_message(attribute, message, @base)
    end

    # Translates an error message in its default scope
    # (<tt>activemodel.errors.messages</tt>).
    #
    # Error messages are first looked up in <tt>activemodel.errors.models.MODEL.attributes.ATTRIBUTE.MESSAGE</tt>,
    # if it's not there, it's looked up in <tt>activemodel.errors.models.MODEL.MESSAGE</tt> and if
    # that is not there also, it returns the translation of the default message
    # (e.g. <tt>activemodel.errors.messages.MESSAGE</tt>). The translated model
    # name, translated attribute name, and the value are available for
    # interpolation.
    #
    # When using inheritance in your models, it will check all the inherited
    # models too, but only if the model itself hasn't been found. Say you have
    # <tt>class Admin < User; end</tt> and you wanted the translation for
    # the <tt>:blank</tt> error message for the <tt>title</tt> attribute,
    # it looks for these translations:
    #
    # * <tt>activemodel.errors.models.admin.attributes.title.blank</tt>
    # * <tt>activemodel.errors.models.admin.blank</tt>
    # * <tt>activemodel.errors.models.user.attributes.title.blank</tt>
    # * <tt>activemodel.errors.models.user.blank</tt>
    # * any default you provided through the +options+ hash (in the <tt>activemodel.errors</tt> scope)
    # * <tt>activemodel.errors.messages.blank</tt>
    # * <tt>errors.attributes.title.blank</tt>
    # * <tt>errors.messages.blank</tt>
    def generate_message(attribute, type = :invalid, options = {})
      Error.generate_message(attribute, type, @base, options)
    end

    def inspect # :nodoc:
      inspection = @errors.inspect

      "#<#{self.class.name} #{inspection}>"
    end

    private
      def normalize_arguments(attribute, type, **options)
        # Evaluate proc first
        if type.respond_to?(:call)
          type = type.call(@base, options)
        end

        [attribute.to_sym, type, options]
      end
  end

  # Raised when a validation cannot be corrected by end users and are considered
  # exceptional.
  #
  #   class Person
  #     include ActiveModel::Validations
  #
  #     attr_accessor :name
  #
  #     validates_presence_of :name, strict: true
  #   end
  #
  #   person = Person.new
  #   person.name = nil
  #   person.valid?
  #   # => ActiveModel::StrictValidationFailed: Name can't be blank
  class StrictValidationFailed < StandardError
  end

  # Raised when attribute values are out of range.
  class RangeError < ::RangeError
  end

  # Raised when unknown attributes are supplied via mass assignment.
  #
  #   class Person
  #     include ActiveModel::AttributeAssignment
  #     include ActiveModel::Validations
  #   end
  #
  #   person = Person.new
  #   person.assign_attributes(name: 'Gorby')
  #   # => ActiveModel::UnknownAttributeError: unknown attribute 'name' for Person.
  class UnknownAttributeError < NoMethodError
    attr_reader :record, :attribute

    def initialize(record, attribute)
      @record = record
      @attribute = attribute
      super("unknown attribute '#{attribute}' for #{@record.class}.")
    end
  end
end

errors_test.rb

# frozen_string_literal: true

require "cases/helper"
require "yaml"

class ErrorsTest < ActiveModel::TestCase
  class Person
    extend ActiveModel::Naming
    def initialize
      @errors = ActiveModel::Errors.new(self)
    end

    attr_accessor :name, :age, :gender, :city
    attr_reader   :errors

    def validate!
      errors.add(:name, :blank, message: "cannot be nil") if name == nil
    end

    def read_attribute_for_validation(attr)
      send(attr)
    end

    def self.human_attribute_name(attr, options = {})
      attr
    end

    def self.lookup_ancestors
      [self]
    end
  end

  def test_delete
    errors = ActiveModel::Errors.new(Person.new)
    errors.add(:name, :blank)
    errors.delete("name")
    assert_empty errors[:name]
  end

  def test_include?
    errors = ActiveModel::Errors.new(Person.new)
    errors.add(:foo, "omg")
    assert_includes errors, :foo, "errors should include :foo"
    assert_includes errors, "foo", "errors should include 'foo' as :foo"
  end

  def test_each_when_arity_is_negative
    errors = ActiveModel::Errors.new(Person.new)
    errors.add(:name, :blank)
    errors.add(:gender, :blank)

    assert_equal([:name, :gender], errors.map(&:attribute))
  end

  def test_any?
    errors = ActiveModel::Errors.new(Person.new)
    errors.add(:name)
    assert errors.any?, "any? should return true"
    assert errors.any? { |_| true }, "any? should return true"
  end

  def test_first
    errors = ActiveModel::Errors.new(Person.new)
    errors.add(:name, :blank)

    error = errors.first
    assert_kind_of ActiveModel::Error, error
  end

  def test_dup
    errors = ActiveModel::Errors.new(Person.new)
    errors.add(:name)
    errors_dup = errors.dup
    assert_not_same errors_dup.errors, errors.errors
  end

  def test_has_key?
    errors = ActiveModel::Errors.new(Person.new)
    errors.add(:foo, "omg")
    assert_equal true, errors.has_key?(:foo), "errors should have key :foo"
    assert_equal true, errors.has_key?("foo"), "errors should have key 'foo' as :foo"
  end

  def test_has_no_key
    errors = ActiveModel::Errors.new(Person.new)
    assert_equal false, errors.has_key?(:name), "errors should not have key :name"
  end

  def test_key?
    errors = ActiveModel::Errors.new(Person.new)
    errors.add(:foo, "omg")
    assert_equal true, errors.key?(:foo), "errors should have key :foo"
    assert_equal true, errors.key?("foo"), "errors should have key 'foo' as :foo"
  end

  def test_no_key
    errors = ActiveModel::Errors.new(Person.new)
    assert_equal false, errors.key?(:name), "errors should not have key :name"
  end

  test "clear errors" do
    person = Person.new
    person.validate!

    assert_equal 1, person.errors.count
    person.errors.clear
    assert_empty person.errors
  end

  test "error access is indifferent" do
    errors = ActiveModel::Errors.new(Person.new)
    errors.add(:name, "omg")

    assert_equal ["omg"], errors["name"]
  end

  test "attribute_names returns the error attributes" do
    errors = ActiveModel::Errors.new(Person.new)
    errors.add(:foo, "omg")
    errors.add(:baz, "zomg")

    assert_equal [:foo, :baz], errors.attribute_names
  end

  test "attribute_names only returns unique attribute names" do
    errors = ActiveModel::Errors.new(Person.new)
    errors.add(:foo, "omg")
    errors.add(:foo, "zomg")

    assert_equal [:foo], errors.attribute_names
  end

  test "attribute_names returns an empty array after try to get a message only" do
    errors = ActiveModel::Errors.new(Person.new)
    errors.messages[:foo]
    errors.messages[:baz]

    assert_equal [], errors.attribute_names
  end

  test "detecting whether there are errors with empty?, blank?, include?" do
    person = Person.new
    person.errors[:foo]
    assert_empty person.errors
    assert_predicate person.errors, :blank?
    assert_not_includes person.errors, :foo

    person.errors.add(:foo, "New error")
    assert_not_empty person.errors
    assert_not_predicate person.errors, :blank?
    assert_includes person.errors, :foo
  end

  test "include? does not add a key to messages hash" do
    person = Person.new
    person.errors.include?(:foo)

    assert_not person.errors.messages.key?(:foo)
  end

  test "adding errors using conditionals with Person#validate!" do
    person = Person.new
    person.validate!
    assert_equal ["name cannot be nil"], person.errors.full_messages
    assert_equal ["cannot be nil"], person.errors[:name]
  end

  test "add creates an error object and returns it" do
    person = Person.new
    error = person.errors.add(:name, :blank)

    assert_equal :name, error.attribute
    assert_equal :blank, error.type
    assert_equal error, person.errors.objects.first
  end

  test "add, with type as symbol" do
    person = Person.new
    person.errors.add(:name, :blank)

    assert_equal :blank, person.errors.objects.first.type
    assert_equal ["can't be blank"], person.errors[:name]
  end

  test "add, with type as String" do
    msg = "custom msg"

    person = Person.new
    person.errors.add(:name, msg)

    assert_equal [msg], person.errors[:name]
  end

  test "add, with type as nil" do
    person = Person.new
    person.errors.add(:name)

    assert_equal :invalid, person.errors.objects.first.type
    assert_equal ["is invalid"], person.errors[:name]
  end

  test "add, with type as Proc, which evaluates to String" do
    msg = "custom msg"
    type = Proc.new { msg }

    person = Person.new
    person.errors.add(:name, type)

    assert_equal [msg], person.errors[:name]
  end

  test "add, type being Proc, which evaluates to Symbol" do
    type = Proc.new { :blank }

    person = Person.new
    person.errors.add(:name, type)

    assert_equal :blank, person.errors.objects.first.type
    assert_equal ["can't be blank"], person.errors[:name]
  end

  test "add an error message on a specific attribute with a defined type" do
    person = Person.new
    person.errors.add(:name, :blank, message: "cannot be blank")
    assert_equal ["cannot be blank"], person.errors[:name]
  end

  test "initialize options[:message] as Proc, which evaluates to String" do
    msg = "custom msg"
    type = Proc.new { msg }

    person = Person.new
    person.errors.add(:name, :blank, message: type)

    assert_equal :blank, person.errors.objects.first.type
    assert_equal [msg], person.errors[:name]
  end

  test "add, with options[:message] as Proc, which evaluates to String, where type is nil" do
    msg = "custom msg"
    type = Proc.new { msg }

    person = Person.new
    person.errors.add(:name, message: type)

    assert_equal :invalid, person.errors.objects.first.type
    assert_equal [msg], person.errors[:name]
  end

  test "added? when attribute was added through a collection" do
    person = Person.new
    person.errors.add(:"family_members.name", :too_long, count: 25)
    assert person.errors.added?(:"family_members.name", :too_long, count: 25)
    assert_not person.errors.added?(:"family_members.name", :too_long)
    assert_not person.errors.added?(:"family_members.name", :too_long, name: "hello")
  end

  test "added? ignores callback option" do
    person = Person.new

    person.errors.add(:name, :too_long, if: -> { true })
    assert person.errors.added?(:name, :too_long)
  end

  test "added? ignores message option" do
    person = Person.new

    person.errors.add(:name, :too_long, message: proc { "foo" })
    assert person.errors.added?(:name, :too_long)
  end

  test "added? detects indifferent if a specific error was added to the object" do
    person = Person.new
    person.errors.add(:name, "cannot be blank")
    assert person.errors.added?(:name, "cannot be blank")
    assert person.errors.added?("name", "cannot be blank")
  end

  test "added? handles symbol message" do
    person = Person.new
    person.errors.add(:name, :blank)
    assert person.errors.added?(:name, :blank)
  end

  test "added? returns true when string attribute is used with a symbol message" do
    person = Person.new
    person.errors.add(:name, :blank)
    assert person.errors.added?("name", :blank)
  end

  test "added? handles proc messages" do
    person = Person.new
    message = Proc.new { "cannot be blank" }
    person.errors.add(:name, message)
    assert person.errors.added?(:name, message)
  end

  test "added? defaults message to :invalid" do
    person = Person.new
    person.errors.add(:name)
    assert person.errors.added?(:name)
  end

  test "added? matches the given message when several errors are present for the same attribute" do
    person = Person.new
    person.errors.add(:name, "cannot be blank")
    person.errors.add(:name, "is invalid")
    assert person.errors.added?(:name, "cannot be blank")
    assert person.errors.added?(:name, "is invalid")
    assert_not person.errors.added?(:name, "incorrect")
  end

  test "added? returns false when no errors are present" do
    person = Person.new
    assert_not person.errors.added?(:name)
  end

  test "added? returns false when checking a nonexisting error and other errors are present for the given attribute" do
    person = Person.new
    person.errors.add(:name, "is invalid")
    assert_not person.errors.added?(:name, "cannot be blank")
  end

  test "added? returns false when checking for an error, but not providing message argument" do
    person = Person.new
    person.errors.add(:name, "cannot be blank")
    assert_not person.errors.added?(:name)
  end

  test "added? returns false when checking for an error with an incorrect or missing option" do
    person = Person.new
    person.errors.add :name, :too_long, count: 25

    assert person.errors.added? :name, :too_long, count: 25
    assert person.errors.added? :name, "is too long (maximum is 25 characters)"
    assert_not person.errors.added? :name, :too_long, count: 24
    assert_not person.errors.added? :name, :too_long
    assert_not person.errors.added? :name, "is too long"
  end

  test "added? returns false when checking for an error by symbol and a different error with same message is present" do
    I18n.backend.store_translations("en", errors: { attributes: { name: { wrong: "is wrong", used: "is wrong" } } })
    person = Person.new
    person.errors.add(:name, :wrong)
    assert_not person.errors.added?(:name, :used)
    assert person.errors.added?(:name, :wrong)
  end

  test "of_kind? returns false when checking for an error, but not providing message argument" do
    person = Person.new
    person.errors.add(:name, "cannot be blank")
    assert_not person.errors.of_kind?(:name)
  end

  test "of_kind? returns false when checking a nonexisting error and other errors are present for the given attribute" do
    person = Person.new
    person.errors.add(:name, "is invalid")
    assert_not person.errors.of_kind?(:name, "cannot be blank")
  end

  test "of_kind? returns false when no errors are present" do
    person = Person.new
    assert_not person.errors.of_kind?(:name)
  end

  test "of_kind? matches the given message when several errors are present for the same attribute" do
    person = Person.new
    person.errors.add(:name, "cannot be blank")
    person.errors.add(:name, "is invalid")
    assert person.errors.of_kind?(:name, "cannot be blank")
    assert person.errors.of_kind?(:name, "is invalid")
    assert_not person.errors.of_kind?(:name, "incorrect")
  end

  test "of_kind? defaults message to :invalid" do
    person = Person.new
    person.errors.add(:name)
    assert person.errors.of_kind?(:name)
  end

  test "of_kind? handles proc messages" do
    person = Person.new
    message = Proc.new { "cannot be blank" }
    person.errors.add(:name, message)
    assert person.errors.of_kind?(:name, message)
  end

  test "of_kind? returns true when string attribute is used with a symbol message" do
    person = Person.new
    person.errors.add(:name, :blank)
    assert person.errors.of_kind?("name", :blank)
  end

  test "of_kind? handles symbol message" do
    person = Person.new
    person.errors.add(:name, :blank)
    assert person.errors.of_kind?(:name, :blank)
  end

  test "of_kind? detects indifferent if a specific error was added to the object" do
    person = Person.new
    person.errors.add(:name, "cannot be blank")
    assert person.errors.of_kind?(:name, "cannot be blank")
    assert person.errors.of_kind?("name", "cannot be blank")
  end

  test "of_kind? ignores options" do
    person = Person.new
    person.errors.add :name, :too_long, count: 25

    assert person.errors.of_kind? :name, :too_long
    assert person.errors.of_kind? :name, "is too long (maximum is 25 characters)"
  end

  test "of_kind? returns false when checking for an error by symbol and a different error with same message is present" do
    I18n.backend.store_translations("en", errors: { attributes: { name: { wrong: "is wrong", used: "is wrong" } } })
    person = Person.new
    person.errors.add(:name, :wrong)
    assert_not person.errors.of_kind?(:name, :used)
    assert person.errors.of_kind?(:name, :wrong)
  end

  test "size calculates the number of error messages" do
    person = Person.new
    person.errors.add(:name, "cannot be blank")
    assert_equal 1, person.errors.size
  end

  test "count calculates the number of error messages" do
    person = Person.new
    person.errors.add(:name, "cannot be blank")
    assert_equal 1, person.errors.count
  end

  test "to_a returns the list of errors with complete messages containing the attribute names" do
    person = Person.new
    person.errors.add(:name, "cannot be blank")
    person.errors.add(:name, "cannot be nil")
    assert_equal ["name cannot be blank", "name cannot be nil"], person.errors.to_a
  end

  test "to_hash returns the error messages hash" do
    person = Person.new
    person.errors.add(:name, "cannot be blank")
    assert_equal({ name: ["cannot be blank"] }, person.errors.to_hash)
  end

  test "to_hash returns a hash without default proc" do
    person = Person.new
    assert_nil person.errors.to_hash.default_proc
  end

  test "as_json returns a hash without default proc" do
    person = Person.new
    assert_nil person.errors.as_json.default_proc
  end

  test "messages returns empty frozen array when when accessed with non-existent attribute" do
    errors = ActiveModel::Errors.new(Person.new)

    assert_equal [], errors.messages[:foo]
    assert_raises(FrozenError) { errors.messages[:foo] << "foo" }
    assert_raises(FrozenError) { errors.messages[:foo].clear }
  end

  test "full_messages doesn't require the base object to respond to `:errors" do
    model = Class.new do
      def initialize
        @errors = ActiveModel::Errors.new(self)
        @errors.add(:name, "bar")
      end

      def self.human_attribute_name(attr, options = {})
        "foo"
      end

      def call
        error_wrapper = Struct.new(:model_errors)

        error_wrapper.new(@errors)
      end
    end

    assert_equal(["foo bar"], model.new.call.model_errors.full_messages)
  end

  test "full_messages creates a list of error messages with the attribute name included" do
    person = Person.new
    person.errors.add(:name, "cannot be blank")
    person.errors.add(:name, "cannot be nil")
    assert_equal ["name cannot be blank", "name cannot be nil"], person.errors.full_messages
  end

  test "full_messages_for contains all the error messages for the given attribute indifferent" do
    person = Person.new
    person.errors.add(:name, "cannot be blank")
    person.errors.add(:name, "cannot be nil")
    assert_equal ["name cannot be blank", "name cannot be nil"], person.errors.full_messages_for(:name)
  end

  test "full_messages_for does not contain error messages from other attributes" do
    person = Person.new
    person.errors.add(:name, "cannot be blank")
    person.errors.add(:email, "cannot be blank")
    assert_equal ["name cannot be blank"], person.errors.full_messages_for(:name)
    assert_equal ["name cannot be blank"], person.errors.full_messages_for("name")
  end

  test "full_messages_for returns an empty list in case there are no errors for the given attribute" do
    person = Person.new
    person.errors.add(:name, "cannot be blank")
    assert_equal [], person.errors.full_messages_for(:email)
  end

  test "full_message returns the given message when attribute is :base" do
    person = Person.new
    assert_equal "press the button", person.errors.full_message(:base, "press the button")
  end

  test "full_message returns the given message with the attribute name included" do
    person = Person.new
    assert_equal "name cannot be blank", person.errors.full_message(:name, "cannot be blank")
    assert_equal "name_test cannot be blank", person.errors.full_message(:name_test, "cannot be blank")
  end

  test "as_json creates a json formatted representation of the errors hash" do
    person = Person.new
    person.validate!

    assert_equal({ name: ["cannot be nil"] }, person.errors.as_json)
  end

  test "as_json with :full_messages option creates a json formatted representation of the errors containing complete messages" do
    person = Person.new
    person.validate!

    assert_equal({ name: ["name cannot be nil"] }, person.errors.as_json(full_messages: true))
  end

  test "generate_message works without i18n_scope" do
    person = Person.new
    assert_not_respond_to Person, :i18n_scope
    assert_nothing_raised {
      person.errors.generate_message(:name, :blank)
    }
  end

  test "details returns added error detail" do
    person = Person.new
    person.errors.add(:name, :invalid)
    assert_equal({ name: [{ error: :invalid }] }, person.errors.details)
  end

  test "details returns added error detail with custom option" do
    person = Person.new
    person.errors.add(:name, :greater_than, count: 5)
    assert_equal({ name: [{ error: :greater_than, count: 5 }] }, person.errors.details)
  end

  test "details do not include message option" do
    person = Person.new
    person.errors.add(:name, :invalid, message: "is bad")
    assert_equal({ name: [{ error: :invalid }] }, person.errors.details)
  end

  test "details retains original type as error" do
    errors = ActiveModel::Errors.new(Person.new)
    errors.add(:name, "cannot be nil")
    errors.add("foo", "bar")
    errors.add(:baz, nil)
    errors.add(:age, :invalid, count: 3, message: "%{count} is too low")

    assert_equal(
      {
        name: [{ error: "cannot be nil" }],
        foo: [{ error: "bar" }],
        baz: [{ error: nil }],
        age: [{ error: :invalid, count: 3 }]
      },
      errors.details
    )
  end

  test "group_by_attribute" do
    person = Person.new
    error = person.errors.add(:name, :invalid, message: "is bad")
    hash = person.errors.group_by_attribute

    assert_equal({ name: [error] }, hash)
  end

  test "dup duplicates details" do
    errors = ActiveModel::Errors.new(Person.new)
    errors.add(:name, :invalid)
    errors_dup = errors.dup
    errors_dup.add(:name, :taken)
    assert_not_equal errors_dup.details, errors.details
  end

  test "delete returns nil when no errors were deleted" do
    errors = ActiveModel::Errors.new(Person.new)

    assert_nil(errors.delete(:name))
  end

  test "delete removes details on given attribute" do
    errors = ActiveModel::Errors.new(Person.new)
    errors.add(:name, :invalid)
    errors.delete(:name)
    assert_not errors.added?(:name)
  end

  test "delete returns the deleted messages" do
    errors = ActiveModel::Errors.new(Person.new)
    errors.add(:name, :invalid)
    assert_equal ["is invalid"], errors.delete(:name)
  end

  test "clear removes details" do
    person = Person.new
    person.errors.add(:name, :invalid)

    assert_equal 1, person.errors.details.count
    person.errors.clear
    assert_empty person.errors.details
  end

  test "details returns empty array when accessed with non-existent attribute" do
    errors = ActiveModel::Errors.new(Person.new)

    assert_equal [], errors.details[:foo]
    assert_raises(FrozenError) { errors.details[:foo] << "foo" }
    assert_raises(FrozenError) { errors.details[:foo].clear }
  end

  test "copy errors" do
    errors = ActiveModel::Errors.new(Person.new)
    errors.add(:name, :invalid)
    person = Person.new
    person.errors.copy!(errors)

    assert person.errors.added?(:name, :invalid)
    person.errors.each do |error|
      assert_same person, error.base
    end
  end

  test "merge errors" do
    errors = ActiveModel::Errors.new(Person.new)
    errors.add(:name, :invalid)

    person = Person.new
    person.errors.add(:name, :blank)
    person.errors.merge!(errors)

    assert(person.errors.added?(:name, :invalid))
    assert(person.errors.added?(:name, :blank))
  end

  test "merge does not import errors when merging with self" do
    errors = ActiveModel::Errors.new(Person.new)
    errors.add(:name, :invalid)
    errors_before_merge = errors.dup

    errors.merge!(errors)

    assert_equal errors.errors, errors_before_merge.errors
  end

  test "errors are marshalable" do
    errors = ActiveModel::Errors.new(Person.new)
    errors.add(:name, :invalid)
    serialized = Marshal.load(Marshal.dump(errors))

    assert_equal Person, serialized.instance_variable_get(:@base).class
    assert_equal errors.messages, serialized.messages
    assert_equal errors.details, serialized.details
  end

  test "errors are compatible with YAML dumped from Rails 6.x" do
    yaml = <<~CODE
    --- !ruby/object:ActiveModel::Errors
    base: &1 !ruby/object:ErrorsTest::Person
      errors: !ruby/object:ActiveModel::Errors
        base: *1
        errors: []
    errors:
    - !ruby/object:ActiveModel::Error
      base: *1
      attribute: :name
      type: :invalid
      raw_type: :invalid
      options: {}
    CODE

    errors = YAML.respond_to?(:unsafe_load) ? YAML.unsafe_load(yaml) : YAML.load(yaml)
    assert_equal({ name: ["is invalid"] }, errors.messages)
    assert_equal({ name: [{ error: :invalid }] }, errors.details)

    errors.clear
    assert_equal({}, errors.messages)
    assert_equal({}, errors.details)
  end

  test "inspect" do
    errors = ActiveModel::Errors.new(Person.new)
    errors.add(:base)

    assert_equal(%(#<ActiveModel::Errors [#{errors.first.inspect}]>), errors.inspect)
  end
end

exclusion.rb

# frozen_string_literal: true

require "active_model/validations/clusivity"

module ActiveModel
  module Validations
    class ExclusionValidator < EachValidator # :nodoc:
      include Clusivity

      def validate_each(record, attribute, value)
        if include?(record, value)
          record.errors.add(attribute, :exclusion, **options.except(:in, :within).merge!(value: value))
        end
      end
    end

    module HelperMethods
      # Validates that the value of the specified attribute is not in a
      # particular enumerable object.
      #
      #   class Person < ActiveRecord::Base
      #     validates_exclusion_of :username, in: %w( admin superuser ), message: "You don't belong here"
      #     validates_exclusion_of :age, in: 30..60, message: 'This site is only for under 30 and over 60'
      #     validates_exclusion_of :format, in: %w( mov avi ), message: "extension %{value} is not allowed"
      #     validates_exclusion_of :password, in: ->(person) { [person.username, person.first_name] },
      #                            message: 'should not be the same as your username or first name'
      #     validates_exclusion_of :karma, in: :reserved_karmas
      #   end
      #
      # Configuration options:
      # * <tt>:in</tt> - An enumerable object of items that the value shouldn't
      #   be part of. This can be supplied as a proc, lambda, or symbol which returns an
      #   enumerable. If the enumerable is a numerical, time, or datetime range the test
      #   is performed with <tt>Range#cover?</tt>, otherwise with <tt>include?</tt>. When
      #   using a proc or lambda the instance under validation is passed as an argument.
      # * <tt>:within</tt> - A synonym(or alias) for <tt>:in</tt>
      #   <tt>Range#cover?</tt>, otherwise with <tt>include?</tt>.
      # * <tt>:message</tt> - Specifies a custom error message (default is: "is
      #   reserved").
      #
      # There is also a list of default options supported by every validator:
      # +:if+, +:unless+, +:on+, +:allow_nil+, +:allow_blank+, and +:strict+.
      # See ActiveModel::Validations::ClassMethods#validates for more information.
      def validates_exclusion_of(*attr_names)
        validates_with ExclusionValidator, _merge_attributes(attr_names)
      end
    end
  end
end

exclusion_validation_test.rb

# frozen_string_literal: true

require "cases/helper"
require "active_support/core_ext/numeric/time"

require "models/topic"
require "models/person"

class ExclusionValidationTest < ActiveModel::TestCase
  def teardown
    Topic.clear_validators!
  end

  def test_validates_exclusion_of
    Topic.validates_exclusion_of(:title, in: %w( abe monkey ))

    assert_predicate Topic.new("title" => "something", "content" => "abc"), :valid?
    assert_predicate Topic.new("title" => "monkey", "content" => "abc"), :invalid?
  end

  def test_validates_exclusion_of_with_formatted_message
    Topic.validates_exclusion_of(:title, in: %w( abe monkey ), message: "option %{value} is restricted")

    assert Topic.new("title" => "something", "content" => "abc")

    t = Topic.new("title" => "monkey")
    assert_predicate t, :invalid?
    assert_predicate t.errors[:title], :any?
    assert_equal ["option monkey is restricted"], t.errors[:title]
  end

  def test_validates_exclusion_of_with_within_option
    Topic.validates_exclusion_of(:title, within: %w( abe monkey ))

    assert Topic.new("title" => "something", "content" => "abc")

    t = Topic.new("title" => "monkey")
    assert_predicate t, :invalid?
    assert_predicate t.errors[:title], :any?
  end

  def test_validates_exclusion_of_for_ruby_class
    Person.validates_exclusion_of :karma, in: %w( abe monkey )

    p = Person.new
    p.karma = "abe"
    assert_predicate p, :invalid?

    assert_equal ["is reserved"], p.errors[:karma]

    p.karma = "Lifo"
    assert_predicate p, :valid?
  ensure
    Person.clear_validators!
  end

  def test_validates_exclusion_of_with_lambda
    Topic.validates_exclusion_of :title, in: lambda { |topic| topic.author_name == "sikachu" ? %w( monkey elephant ) : %w( abe wasabi ) }

    t = Topic.new
    t.title = "elephant"
    t.author_name = "sikachu"
    assert_predicate t, :invalid?

    t.title = "wasabi"
    assert_predicate t, :valid?
  end

  def test_validates_exclusion_of_with_range
    Topic.validates_exclusion_of :content, in: ("a".."g")

    assert_predicate Topic.new(content: "g"), :invalid?
    assert_predicate Topic.new(content: "h"), :valid?
  end

  def test_validates_exclusion_of_with_time_range
    Topic.validates_exclusion_of :created_at, in: 6.days.ago..2.days.ago

    assert_predicate Topic.new(created_at: 5.days.ago), :invalid?
    assert_predicate Topic.new(created_at: 3.days.ago), :invalid?
    assert_predicate Topic.new(created_at: 7.days.ago), :valid?
    assert_predicate Topic.new(created_at: 1.day.ago), :valid?
  end

  def test_validates_inclusion_of_with_symbol
    Person.validates_exclusion_of :karma, in: :reserved_karmas

    p = Person.new
    p.karma = "abe"

    def p.reserved_karmas
      %w(abe)
    end

    assert_predicate p, :invalid?
    assert_equal ["is reserved"], p.errors[:karma]

    p = Person.new
    p.karma = "abe"

    def p.reserved_karmas
      %w()
    end

    assert_predicate p, :valid?
  ensure
    Person.clear_validators!
  end
end

float.rb

# frozen_string_literal: true

require "active_support/core_ext/object/try"

module ActiveModel
  module Type
    # Attribute type for floating point numeric values. It is registered under
    # the +:float+ key.
    #
    #   class BagOfCoffee
    #     include ActiveModel::Attributes
    #
    #     attribute :weight, :float
    #   end
    #
    #   bag = BagOfCoffee.new
    #   bag.weight = "0.25"
    #
    #   bag.weight # => 0.25
    #
    # Values are coerced to their float representation using their +to_f+
    # methods. However, the following strings which represent floating point
    # constants are cast accordingly:
    #
    # - <tt>"Infinity"</tt> is cast to <tt>Float::INFINITY</tt>.
    # - <tt>"-Infinity"</tt> is cast to <tt>-Float::INFINITY</tt>.
    # - <tt>"NaN"</tt> is cast to <tt>Float::NAN</tt>.
    class Float < Value
      include Helpers::Numeric

      def type
        :float
      end

      def type_cast_for_schema(value)
        return "::Float::NAN" if value.try(:nan?)
        case value
        when ::Float::INFINITY then "::Float::INFINITY"
        when -::Float::INFINITY then "-::Float::INFINITY"
        else super
        end
      end

      private
        def cast_value(value)
          case value
          when ::Float then value
          when "Infinity" then ::Float::INFINITY
          when "-Infinity" then -::Float::INFINITY
          when "NaN" then ::Float::NAN
          else value.to_f
          end
        end
    end
  end
end

float_test.rb

# frozen_string_literal: true

require "cases/helper"

module ActiveModel
  module Type
    class FloatTest < ActiveModel::TestCase
      def test_type_cast_float
        type = Type::Float.new
        assert_equal 1.0, type.cast("1")
      end

      def test_type_cast_float_from_invalid_string
        type = Type::Float.new
        assert_nil type.cast("")
        assert_equal 1.0, type.cast("1ignore")
        assert_equal 0.0, type.cast("bad1")
        assert_equal 0.0, type.cast("bad")
      end

      def test_changing_float
        type = Type::Float.new

        assert type.changed?(0.0, 0, "wibble")
        assert type.changed?(5.0, 0, "wibble")
        assert_not type.changed?(5.0, 5.0, "5wibble")
        assert_not type.changed?(5.0, 5.0, "5")
        assert_not type.changed?(5.0, 5.0, "5.0")
        assert_not type.changed?(500.0, 500.0, "0.5E+4")
        assert_not type.changed?(nil, nil, nil)
        assert_not type.changed?(0.0 / 0.0, 0.0 / 0.0, 0.0 / 0.0)
        assert type.changed?(0.0 / 0.0, BigDecimal("0.0") / 0, BigDecimal("0.0") / 0)
      end
    end
  end
end

forbidden_attributes_protection.rb

# frozen_string_literal: true

module ActiveModel
  # Raised when forbidden attributes are used for mass assignment.
  #
  #   class Person < ActiveRecord::Base
  #   end
  #
  #   params = ActionController::Parameters.new(name: 'Bob')
  #   Person.new(params)
  #   # => ActiveModel::ForbiddenAttributesError
  #
  #   params.permit!
  #   Person.new(params)
  #   # => #<Person id: nil, name: "Bob">
  class ForbiddenAttributesError < StandardError
  end

  module ForbiddenAttributesProtection # :nodoc:
    private
      def sanitize_for_mass_assignment(attributes)
        if attributes.respond_to?(:permitted?)
          raise ActiveModel::ForbiddenAttributesError if !attributes.permitted?
          attributes.to_h
        else
          attributes
        end
      end
      alias :sanitize_forbidden_attributes :sanitize_for_mass_assignment
  end
end

forbidden_attributes_protection_test.rb

# frozen_string_literal: true

require "cases/helper"
require "active_support/core_ext/hash/indifferent_access"
require "models/account"

class ProtectedParams
  attr_accessor :permitted
  alias :permitted? :permitted

  delegate :keys, :key?, :has_key?, :empty?, to: :@parameters

  def initialize(attributes)
    @parameters = attributes
    @permitted = false
  end

  def permit!
    @permitted = true
    self
  end

  def to_h
    @parameters
  end
end

class ActiveModelMassUpdateProtectionTest < ActiveSupport::TestCase
  test "forbidden attributes cannot be used for mass updating" do
    params = ProtectedParams.new("a" => "b")
    assert_raises(ActiveModel::ForbiddenAttributesError) do
      Account.new.sanitize_for_mass_assignment(params)
    end
  end

  test "permitted attributes can be used for mass updating" do
    params = ProtectedParams.new("a" => "b").permit!
    assert_equal({ "a" => "b" }, Account.new.sanitize_for_mass_assignment(params))
  end

  test "regular attributes should still be allowed" do
    assert_equal({ a: "b" }, Account.new.sanitize_for_mass_assignment(a: "b"))
  end
end

format.rb

# frozen_string_literal: true

module ActiveModel
  module Validations
    class FormatValidator < EachValidator # :nodoc:
      def validate_each(record, attribute, value)
        if options[:with]
          regexp = option_call(record, :with)
          record_error(record, attribute, :with, value) unless regexp.match?(value.to_s)
        elsif options[:without]
          regexp = option_call(record, :without)
          record_error(record, attribute, :without, value) if regexp.match?(value.to_s)
        end
      end

      def check_validity!
        unless options.include?(:with) ^ options.include?(:without)  # ^ == xor, or "exclusive or"
          raise ArgumentError, "Either :with or :without must be supplied (but not both)"
        end

        check_options_validity :with
        check_options_validity :without
      end

      private
        def option_call(record, name)
          option = options[name]
          option.respond_to?(:call) ? option.call(record) : option
        end

        def record_error(record, attribute, name, value)
          record.errors.add(attribute, :invalid, **options.except(name).merge!(value: value))
        end

        def check_options_validity(name)
          if option = options[name]
            if option.is_a?(Regexp)
              if options[:multiline] != true && regexp_using_multiline_anchors?(option)
                raise ArgumentError, "The provided regular expression is using multiline anchors (^ or $), " \
                "which may present a security risk. Did you mean to use \\A and \\z, or forgot to add the " \
                ":multiline => true option?"
              end
            elsif !option.respond_to?(:call)
              raise ArgumentError, "A regular expression or a proc or lambda must be supplied as :#{name}"
            end
          end
        end

        def regexp_using_multiline_anchors?(regexp)
          source = regexp.source
          source.start_with?("^") || (source.end_with?("$") && !source.end_with?("\\$"))
        end
    end

    module HelperMethods
      # Validates whether the value of the specified attribute is of the correct
      # form, going by the regular expression provided. You can require that the
      # attribute matches the regular expression:
      #
      #   class Person < ActiveRecord::Base
      #     validates_format_of :email, with: /\A([^@\s]+)@((?:[-a-z0-9]+\.)+[a-z]{2,})\z/i, on: :create
      #   end
      #
      # Alternatively, you can require that the specified attribute does _not_
      # match the regular expression:
      #
      #   class Person < ActiveRecord::Base
      #     validates_format_of :email, without: /NOSPAM/
      #   end
      #
      # You can also provide a proc or lambda which will determine the regular
      # expression that will be used to validate the attribute.
      #
      #   class Person < ActiveRecord::Base
      #     # Admin can have number as a first letter in their screen name
      #     validates_format_of :screen_name,
      #                         with: ->(person) { person.admin? ? /\A[a-z0-9][a-z0-9_\-]*\z/i : /\A[a-z][a-z0-9_\-]*\z/i }
      #   end
      #
      # Note: use <tt>\A</tt> and <tt>\z</tt> to match the start and end of the
      # string, <tt>^</tt> and <tt>$</tt> match the start/end of a line.
      #
      # Due to frequent misuse of <tt>^</tt> and <tt>$</tt>, you need to pass
      # the <tt>multiline: true</tt> option in case you use any of these two
      # anchors in the provided regular expression. In most cases, you should be
      # using <tt>\A</tt> and <tt>\z</tt>.
      #
      # You must pass either <tt>:with</tt> or <tt>:without</tt> as an option.
      # In addition, both must be a regular expression or a proc or lambda, or
      # else an exception will be raised.
      #
      # Configuration options:
      # * <tt>:message</tt> - A custom error message (default is: "is invalid").
      # * <tt>:with</tt> - Regular expression that if the attribute matches will
      #   result in a successful validation. This can be provided as a proc or
      #   lambda returning regular expression which will be called at runtime.
      # * <tt>:without</tt> - Regular expression that if the attribute does not
      #   match will result in a successful validation. This can be provided as
      #   a proc or lambda returning regular expression which will be called at
      #   runtime.
      # * <tt>:multiline</tt> - Set to true if your regular expression contains
      #   anchors that match the beginning or end of lines as opposed to the
      #   beginning or end of the string. These anchors are <tt>^</tt> and <tt>$</tt>.
      #
      # There is also a list of default options supported by every validator:
      # +:if+, +:unless+, +:on+, +:allow_nil+, +:allow_blank+, and +:strict+.
      # See ActiveModel::Validations::ClassMethods#validates for more information.
      def validates_format_of(*attr_names)
        validates_with FormatValidator, _merge_attributes(attr_names)
      end
    end
  end
end

format_validation_test.rb

# frozen_string_literal: true

require "cases/helper"

require "models/topic"
require "models/person"

class FormatValidationTest < ActiveModel::TestCase
  def teardown
    Topic.clear_validators!
  end

  def test_validate_format
    Topic.validates_format_of(:title, :content, with: /\AValidation\smacros \w+!\z/, message: "is bad data")

    t = Topic.new("title" => "i'm incorrect", "content" => "Validation macros rule!")
    assert t.invalid?, "Shouldn't be valid"
    assert_equal ["is bad data"], t.errors[:title]
    assert_empty t.errors[:content]

    t.title = "Validation macros rule!"

    assert_predicate t, :valid?
    assert_empty t.errors[:title]

    assert_raise(ArgumentError) { Topic.validates_format_of(:title, :content) }
  end

  def test_validate_format_with_allow_blank
    Topic.validates_format_of(:title, with: /\AValidation\smacros \w+!\z/, allow_blank: true)
    assert_predicate Topic.new("title" => "Shouldn't be valid"), :invalid?
    assert_predicate Topic.new("title" => ""), :valid?
    assert_predicate Topic.new("title" => nil), :valid?
    assert_predicate Topic.new("title" => "Validation macros rule!"), :valid?
  end

  # testing ticket #3142
  def test_validate_format_numeric
    Topic.validates_format_of(:title, :content, with: /\A[1-9][0-9]*\z/, message: "is bad data")

    t = Topic.new("title" => "72x", "content" => "6789")
    assert t.invalid?, "Shouldn't be valid"

    assert_equal ["is bad data"], t.errors[:title]
    assert_empty t.errors[:content]

    t.title = "-11"
    assert t.invalid?, "Shouldn't be valid"

    t.title = "03"
    assert t.invalid?, "Shouldn't be valid"

    t.title = "z44"
    assert t.invalid?, "Shouldn't be valid"

    t.title = "5v7"
    assert t.invalid?, "Shouldn't be valid"

    t.title = "1"

    assert_predicate t, :valid?
    assert_empty t.errors[:title]
  end

  def test_validate_format_with_formatted_message
    Topic.validates_format_of(:title, with: /\AValid Title\z/, message: "can't be %{value}")
    t = Topic.new(title: "Invalid title")
    assert_predicate t, :invalid?
    assert_equal ["can't be Invalid title"], t.errors[:title]
  end

  def test_validate_format_of_with_multiline_regexp_should_raise_error
    assert_raise(ArgumentError) { Topic.validates_format_of(:title, with: /^Valid Title$/) }
  end

  def test_validate_format_of_with_multiline_regexp_and_option
    assert_nothing_raised do
      Topic.validates_format_of(:title, with: /^Valid Title$/, multiline: true)
    end
  end

  def test_validate_format_with_not_option
    Topic.validates_format_of(:title, without: /foo/, message: "should not contain foo")
    t = Topic.new

    t.title = "foobar"
    t.valid?
    assert_equal ["should not contain foo"], t.errors[:title]

    t.title = "something else"
    t.valid?
    assert_equal [], t.errors[:title]
  end

  def test_validate_format_of_without_any_regexp_should_raise_error
    assert_raise(ArgumentError) { Topic.validates_format_of(:title) }
  end

  def test_validates_format_of_with_both_regexps_should_raise_error
    assert_raise(ArgumentError) { Topic.validates_format_of(:title, with: /this/, without: /that/) }
  end

  def test_validates_format_of_when_with_isnt_a_regexp_should_raise_error
    assert_raise(ArgumentError) { Topic.validates_format_of(:title, with: "clearly not a regexp") }
  end

  def test_validates_format_of_when_not_isnt_a_regexp_should_raise_error
    assert_raise(ArgumentError) { Topic.validates_format_of(:title, without: "clearly not a regexp") }
  end

  def test_validates_format_of_with_lambda
    Topic.validates_format_of :content, with: lambda { |topic| topic.title == "digit" ? /\A\d+\z/ : /\A\S+\z/ }

    t = Topic.new
    t.title = "digit"
    t.content = "Pixies"
    assert_predicate t, :invalid?

    t.content = "1234"
    assert_predicate t, :valid?
  end

  def test_validates_format_of_without_lambda
    Topic.validates_format_of :content, without: lambda { |topic| topic.title == "characters" ? /\A\d+\z/ : /\A\S+\z/ }

    t = Topic.new
    t.title = "characters"
    t.content = "1234"
    assert_predicate t, :invalid?

    t.content = "Pixies"
    assert_predicate t, :valid?
  end

  def test_validates_format_of_for_ruby_class
    Person.validates_format_of :karma, with: /\A\d+\z/

    p = Person.new
    p.karma = "Pixies"
    assert_predicate p, :invalid?

    assert_equal ["is invalid"], p.errors[:karma]

    p.karma = "1234"
    assert_predicate p, :valid?
  ensure
    Person.clear_validators!
  end
end

gem_version.rb

# frozen_string_literal: true

module ActiveModel
  # Returns the version of the currently loaded \Active \Model as a <tt>Gem::Version</tt>
  def self.gem_version
    Gem::Version.new VERSION::STRING
  end

  module VERSION
    MAJOR = 7
    MINOR = 1
    TINY  = 0
    PRE   = "alpha"

    STRING = [MAJOR, MINOR, TINY, PRE].compact.join(".")
  end
end

helicopter.rb

# frozen_string_literal: true

class Helicopter
  include ActiveModel::Conversion
end

class Helicopter::Comanche
  include ActiveModel::Conversion
end

helper.rb

# frozen_string_literal: true

require "active_model"

# Show backtraces for deprecated behavior for quicker cleanup.
ActiveSupport::Deprecation.debug = true

# Disable available locale checks to avoid warnings running the test suite.
I18n.enforce_available_locales = false

require "active_support/testing/autorun"
require "active_support/testing/method_call_assertions"
require "active_support/core_ext/integer/time"

class ActiveModel::TestCase < ActiveSupport::TestCase
  include ActiveSupport::Testing::MethodCallAssertions

  private
    # Skips the current run on Rubinius using Minitest::Assertions#skip
    def rubinius_skip(message = "")
      skip message if RUBY_ENGINE == "rbx"
    end

    # Skips the current run on JRuby using Minitest::Assertions#skip
    def jruby_skip(message = "")
      skip message if defined?(JRUBY_VERSION)
    end
end

require_relative "../../../tools/test_common"

helper_methods.rb

# frozen_string_literal: true

module ActiveModel
  module Validations
    module HelperMethods # :nodoc:
      private
        def _merge_attributes(attr_names)
          options = attr_names.extract_options!.symbolize_keys
          attr_names.flatten!
          options[:attributes] = attr_names
          options
        end
    end
  end
end

helpers.rb

# frozen_string_literal: true

require "active_model/type/helpers/accepts_multiparameter_time"
require "active_model/type/helpers/numeric"
require "active_model/type/helpers/mutable"
require "active_model/type/helpers/time_value"
require "active_model/type/helpers/timezone"

i18n_generate_message_validation_test.rb

# frozen_string_literal: true

require "cases/helper"

require "models/person"

class I18nGenerateMessageValidationTest < ActiveModel::TestCase
  def setup
    Person.clear_validators!
    @person = Person.new
  end

  # validates_inclusion_of: generate_message(attr_name, :inclusion, message: custom_message, value: value)
  def test_generate_message_inclusion_with_default_message
    assert_equal "is not included in the list", @person.errors.generate_message(:title, :inclusion, value: "title")
  end

  def test_generate_message_inclusion_with_custom_message
    assert_equal "custom message title", @person.errors.generate_message(:title, :inclusion, message: "custom message %{value}", value: "title")
  end

  # validates_exclusion_of: generate_message(attr_name, :exclusion, message: custom_message, value: value)
  def test_generate_message_exclusion_with_default_message
    assert_equal "is reserved", @person.errors.generate_message(:title, :exclusion, value: "title")
  end

  def test_generate_message_exclusion_with_custom_message
    assert_equal "custom message title", @person.errors.generate_message(:title, :exclusion, message: "custom message %{value}", value: "title")
  end

  # validates_format_of:  generate_message(attr_name, :invalid, message: custom_message, value: value)
  def test_generate_message_invalid_with_default_message
    assert_equal "is invalid", @person.errors.generate_message(:title, :invalid, value: "title")
  end

  def test_generate_message_invalid_with_custom_message
    assert_equal "custom message title", @person.errors.generate_message(:title, :invalid, message: "custom message %{value}", value: "title")
  end

  # validates_confirmation_of: generate_message(attr_name, :confirmation, message: custom_message)
  def test_generate_message_confirmation_with_default_message
    assert_equal "doesn't match Title", @person.errors.generate_message(:title, :confirmation)
  end

  def test_generate_message_confirmation_with_custom_message
    assert_equal "custom message", @person.errors.generate_message(:title, :confirmation, message: "custom message")
  end

  # validates_acceptance_of: generate_message(attr_name, :accepted, message: custom_message)
  def test_generate_message_accepted_with_default_message
    assert_equal "must be accepted", @person.errors.generate_message(:title, :accepted)
  end

  def test_generate_message_accepted_with_custom_message
    assert_equal "custom message", @person.errors.generate_message(:title, :accepted, message: "custom message")
  end

  # add_on_empty: generate_message(attr, :empty, message: custom_message)
  def test_generate_message_empty_with_default_message
    assert_equal "can't be empty", @person.errors.generate_message(:title, :empty)
  end

  def test_generate_message_empty_with_custom_message
    assert_equal "custom message", @person.errors.generate_message(:title, :empty, message: "custom message")
  end

  # validates_presence_of: generate_message(attr, :blank, message: custom_message)
  def test_generate_message_blank_with_default_message
    assert_equal "can't be blank", @person.errors.generate_message(:title, :blank)
  end

  def test_generate_message_blank_with_custom_message
    assert_equal "custom message", @person.errors.generate_message(:title, :blank, message: "custom message")
  end

  # validates_length_of: generate_message(attr, :too_long, message: custom_message, count: option_value.end)
  def test_generate_message_too_long_with_default_message_plural
    assert_equal "is too long (maximum is 10 characters)", @person.errors.generate_message(:title, :too_long, count: 10)
  end

  def test_generate_message_too_long_with_default_message_singular
    assert_equal "is too long (maximum is 1 character)", @person.errors.generate_message(:title, :too_long, count: 1)
  end

  def test_generate_message_too_long_with_custom_message
    assert_equal "custom message 10", @person.errors.generate_message(:title, :too_long, message: "custom message %{count}", count: 10)
  end

  # validates_length_of: generate_message(attr, :too_short, default: custom_message, count: option_value.begin)
  def test_generate_message_too_short_with_default_message_plural
    assert_equal "is too short (minimum is 10 characters)", @person.errors.generate_message(:title, :too_short, count: 10)
  end

  def test_generate_message_too_short_with_default_message_singular
    assert_equal "is too short (minimum is 1 character)", @person.errors.generate_message(:title, :too_short, count: 1)
  end

  def test_generate_message_too_short_with_custom_message
    assert_equal "custom message 10", @person.errors.generate_message(:title, :too_short, message: "custom message %{count}", count: 10)
  end

  # validates_length_of: generate_message(attr, :wrong_length, message: custom_message, count: option_value)
  def test_generate_message_wrong_length_with_default_message_plural
    assert_equal "is the wrong length (should be 10 characters)", @person.errors.generate_message(:title, :wrong_length, count: 10)
  end

  def test_generate_message_wrong_length_with_default_message_singular
    assert_equal "is the wrong length (should be 1 character)", @person.errors.generate_message(:title, :wrong_length, count: 1)
  end

  def test_generate_message_wrong_length_with_custom_message
    assert_equal "custom message 10", @person.errors.generate_message(:title, :wrong_length, message: "custom message %{count}", count: 10)
  end

  # validates_numericality_of: generate_message(attr_name, :not_a_number, value: raw_value, message: custom_message)
  def test_generate_message_not_a_number_with_default_message
    assert_equal "is not a number", @person.errors.generate_message(:title, :not_a_number, value: "title")
  end

  def test_generate_message_not_a_number_with_custom_message
    assert_equal "custom message title", @person.errors.generate_message(:title, :not_a_number, message: "custom message %{value}", value: "title")
  end

  # validates_numericality_of: generate_message(attr_name, option, value: raw_value, default: custom_message)
  def test_generate_message_greater_than_with_default_message
    assert_equal "must be greater than 10", @person.errors.generate_message(:title, :greater_than, value: "title", count: 10)
  end

  def test_generate_message_greater_than_or_equal_to_with_default_message
    assert_equal "must be greater than or equal to 10", @person.errors.generate_message(:title, :greater_than_or_equal_to, value: "title", count: 10)
  end

  def test_generate_message_equal_to_with_default_message
    assert_equal "must be equal to 10", @person.errors.generate_message(:title, :equal_to, value: "title", count: 10)
  end

  def test_generate_message_less_than_with_default_message
    assert_equal "must be less than 10", @person.errors.generate_message(:title, :less_than, value: "title", count: 10)
  end

  def test_generate_message_less_than_or_equal_to_with_default_message
    assert_equal "must be less than or equal to 10", @person.errors.generate_message(:title, :less_than_or_equal_to, value: "title", count: 10)
  end

  def test_generate_message_odd_with_default_message
    assert_equal "must be odd", @person.errors.generate_message(:title, :odd, value: "title", count: 10)
  end

  def test_generate_message_even_with_default_message
    assert_equal "must be even", @person.errors.generate_message(:title, :even, value: "title", count: 10)
  end
end

i18n_validation_test.rb

# frozen_string_literal: true

require "cases/helper"
require "models/person"

class I18nValidationTest < ActiveModel::TestCase
  def setup
    Person.clear_validators!
    @person = person_class.new

    @old_load_path, @old_backend = I18n.load_path.dup, I18n.backend
    I18n.load_path.clear
    I18n.backend = I18n::Backend::Simple.new
    I18n.backend.store_translations("en", errors: { messages: { custom: nil } })

    @original_i18n_customize_full_message = ActiveModel::Error.i18n_customize_full_message
    ActiveModel::Error.i18n_customize_full_message = true
  end

  def teardown
    person_class.clear_validators!
    self.class.send(:remove_const, :Person)
    @person_stub = nil
    I18n.load_path.replace @old_load_path
    I18n.backend = @old_backend
    I18n.backend.reload!
    ActiveModel::Error.i18n_customize_full_message = @original_i18n_customize_full_message
  end

  def test_full_message_encoding
    I18n.backend.store_translations("en", errors: {
      messages: { too_short: "猫舌" } })
    person_class.validates_length_of :title, within: 3..5
    @person.valid?
    assert_equal ["Title 猫舌"], @person.errors.full_messages
  end

  def test_errors_full_messages_translates_human_attribute_name_for_model_attributes
    @person.errors.add(:name, "not found")
    assert_called_with(person_class, :human_attribute_name, ["name", default: "Name", base: @person], returns: "Person's name") do
      assert_equal ["Person's name not found"], @person.errors.full_messages
    end
  end

  def test_errors_full_messages_uses_format
    I18n.backend.store_translations("en", errors: { format: "Field %{attribute} %{message}" })
    @person.errors.add("name", "empty")
    assert_equal ["Field Name empty"], @person.errors.full_messages
  end

  def test_errors_full_messages_doesnt_use_attribute_format_without_config
    ActiveModel::Error.i18n_customize_full_message = false

    I18n.backend.store_translations("en", activemodel: {
      errors: { models: { person: { attributes: { name: { format: "%{message}" } } } } } })

    person = person_class.new
    assert_equal "Name cannot be blank", person.errors.full_message(:name, "cannot be blank")
    assert_equal "Name test cannot be blank", person.errors.full_message(:name_test, "cannot be blank")
  end

  def test_errors_full_messages_on_nested_error_uses_attribute_format
    ActiveModel::Error.i18n_customize_full_message = true
    I18n.backend.store_translations("en", activemodel: {
      errors: { models: { person: { attributes: { gender: "Gender" } } } },
      attributes: { "person/contacts": { gender: "Gender" } }
    })

    person = person_class.new
    error = ActiveModel::Error.new(person, :gender, "can't be blank")
    person.errors.import(error, attribute: "person[0].contacts.gender")
    assert_equal ["Gender can't be blank"], person.errors.full_messages
  end

  def test_errors_full_messages_uses_attribute_format
    ActiveModel::Error.i18n_customize_full_message = true

    I18n.backend.store_translations("en", activemodel: {
      errors: { models: { person: { attributes: { name: { format: "%{message}" } } } } } })

    person = person_class.new
    assert_equal "cannot be blank", person.errors.full_message(:name, "cannot be blank")
    assert_equal "Name test cannot be blank", person.errors.full_message(:name_test, "cannot be blank")
  end

  def test_errors_full_messages_uses_model_format
    ActiveModel::Error.i18n_customize_full_message = true

    I18n.backend.store_translations("en", activemodel: {
      errors: { models: { person: { format: "%{message}" } } } })

    person = person_class.new
    assert_equal "cannot be blank", person.errors.full_message(:name, "cannot be blank")
    assert_equal "cannot be blank", person.errors.full_message(:name_test, "cannot be blank")
  end

  def test_errors_full_messages_uses_deeply_nested_model_attributes_format
    ActiveModel::Error.i18n_customize_full_message = true

    I18n.backend.store_translations("en", activemodel: {
      errors: { models: { 'person/contacts/addresses': { attributes: { street: { format: "%{message}" } } } } } })

    person = person_class.new
    assert_equal "cannot be blank", person.errors.full_message(:'contacts/addresses.street', "cannot be blank")
    assert_equal "Contacts/addresses country cannot be blank", person.errors.full_message(:'contacts/addresses.country', "cannot be blank")
  end

  def test_errors_full_messages_uses_deeply_nested_model_model_format
    ActiveModel::Error.i18n_customize_full_message = true

    I18n.backend.store_translations("en", activemodel: {
      errors: { models: { 'person/contacts/addresses': { format: "%{message}" } } } })

    person = person_class.new
    assert_equal "cannot be blank", person.errors.full_message(:'contacts/addresses.street', "cannot be blank")
    assert_equal "cannot be blank", person.errors.full_message(:'contacts/addresses.country', "cannot be blank")
  end

  def test_errors_full_messages_with_indexed_deeply_nested_attributes_and_attributes_format
    ActiveModel::Error.i18n_customize_full_message = true

    I18n.backend.store_translations("en", activemodel: {
      errors: { models: { 'person/contacts/addresses': { attributes: { street: { format: "%{message}" } } } } } })

    person = person_class.new
    assert_equal "cannot be blank", person.errors.full_message(:'contacts[0]/addresses[123].street', "cannot be blank")
    assert_equal "Contacts/addresses country cannot be blank", person.errors.full_message(:'contacts[0]/addresses[123].country', "cannot be blank")
  end

  def test_errors_full_messages_with_indexed_deeply_nested_attributes_and_model_format
    ActiveModel::Error.i18n_customize_full_message = true

    I18n.backend.store_translations("en", activemodel: {
      errors: { models: { 'person/contacts/addresses': { format: "%{message}" } } } })

    person = person_class.new
    assert_equal "cannot be blank", person.errors.full_message(:'contacts[0]/addresses[123].street', "cannot be blank")
    assert_equal "cannot be blank", person.errors.full_message(:'contacts[0]/addresses[123].country', "cannot be blank")
  end

  def test_errors_full_messages_with_indexed_deeply_nested_attributes_and_i18n_attribute_name
    ActiveModel::Error.i18n_customize_full_message = true

    I18n.backend.store_translations("en", activemodel: {
      attributes: { 'person/contacts/addresses': { country: "Country" } }
    })

    person = person_class.new
    assert_equal "Contacts/addresses street cannot be blank", person.errors.full_message(:'contacts[0]/addresses[123].street', "cannot be blank")
    assert_equal "Country cannot be blank", person.errors.full_message(:'contacts[0]/addresses[123].country', "cannot be blank")
  end

  def test_errors_full_messages_with_indexed_deeply_nested_attributes_without_i18n_config
    ActiveModel::Error.i18n_customize_full_message = false

    I18n.backend.store_translations("en", activemodel: {
      errors: { models: { 'person/contacts/addresses': { attributes: { street: { format: "%{message}" } } } } } })

    person = person_class.new
    assert_equal "Contacts[0]/addresses[0] street cannot be blank", person.errors.full_message(:'contacts[0]/addresses[0].street', "cannot be blank")
    assert_equal "Contacts[0]/addresses[0] country cannot be blank", person.errors.full_message(:'contacts[0]/addresses[0].country', "cannot be blank")
  end

  def test_errors_full_messages_with_i18n_attribute_name_without_i18n_config
    ActiveModel::Error.i18n_customize_full_message = false

    I18n.backend.store_translations("en", activemodel: {
      attributes: { 'person/contacts[0]/addresses[0]': { country: "Country" } }
    })

    person = person_class.new
    assert_equal "Contacts[0]/addresses[0] street cannot be blank", person.errors.full_message(:'contacts[0]/addresses[0].street', "cannot be blank")
    assert_equal "Country cannot be blank", person.errors.full_message(:'contacts[0]/addresses[0].country', "cannot be blank")
  end

  # ActiveModel::Validations

  # A set of common cases for ActiveModel::Validations message generation that
  # are used to generate tests to keep things DRY
  #
  COMMON_CASES = [
    # [ case,                              validation_options,            generate_message_options]
    [ "given no options",                  {},                            {}],
    [ "given custom message",              { message: "custom" },         { message: "custom" }],
    [ "given if condition",                { if: lambda { true } },       {}],
    [ "given unless condition",            { unless: lambda { false } },  {}],
    [ "given option that is not reserved", { format: "jpg" },             { format: "jpg" }]
  ]

  COMMON_CASES.each do |name, validation_options, generate_message_options|
    test "validates_confirmation_of on generated message #{name}" do
      person_class.validates_confirmation_of :title, validation_options
      @person.title_confirmation = "foo"
      call = [:title_confirmation, :confirmation, @person, generate_message_options.merge(attribute: "Title")]
      assert_called_with(ActiveModel::Error, :generate_message, call) do
        @person.valid?
        @person.errors.messages
      end
    end
  end

  COMMON_CASES.each do |name, validation_options, generate_message_options|
    test "validates_acceptance_of on generated message #{name}" do
      person_class.validates_acceptance_of :title, validation_options.merge(allow_nil: false)
      call = [:title, :accepted, @person, generate_message_options]
      assert_called_with(ActiveModel::Error, :generate_message, call) do
        @person.valid?
        @person.errors.messages
      end
    end
  end

  COMMON_CASES.each do |name, validation_options, generate_message_options|
    test "validates_presence_of on generated message #{name}" do
      person_class.validates_presence_of :title, validation_options
      call = [:title, :blank, @person, generate_message_options]
      assert_called_with(ActiveModel::Error, :generate_message, call) do
        @person.valid?
        @person.errors.messages
      end
    end
  end

  COMMON_CASES.each do |name, validation_options, generate_message_options|
    test "validates_length_of for :within on generated message when too short #{name}" do
      person_class.validates_length_of :title, validation_options.merge(within: 3..5)
      call = [:title, :too_short, @person, generate_message_options.merge(count: 3)]
      assert_called_with(ActiveModel::Error, :generate_message, call) do
        @person.valid?
        @person.errors.messages
      end
    end
  end

  COMMON_CASES.each do |name, validation_options, generate_message_options|
    test "validates_length_of for :too_long generated message #{name}" do
      person_class.validates_length_of :title, validation_options.merge(within: 3..5)
      @person.title = "this title is too long"
      call = [:title, :too_long, @person, generate_message_options.merge(count: 5)]
      assert_called_with(ActiveModel::Error, :generate_message, call) do
        @person.valid?
        @person.errors.messages
      end
    end
  end

  COMMON_CASES.each do |name, validation_options, generate_message_options|
    test "validates_length_of for :is on generated message #{name}" do
      person_class.validates_length_of :title, validation_options.merge(is: 5)
      call = [:title, :wrong_length, @person, generate_message_options.merge(count: 5)]
      assert_called_with(ActiveModel::Error, :generate_message, call) do
        @person.valid?
        @person.errors.messages
      end
    end
  end

  COMMON_CASES.each do |name, validation_options, generate_message_options|
    test "validates_format_of on generated message #{name}" do
      person_class.validates_format_of :title, validation_options.merge(with: /\A[1-9][0-9]*\z/)
      @person.title = "72x"
      call = [:title, :invalid, @person, generate_message_options.merge(value: "72x")]
      assert_called_with(ActiveModel::Error, :generate_message, call) do
        @person.valid?
        @person.errors.messages
      end
    end
  end

  COMMON_CASES.each do |name, validation_options, generate_message_options|
    test "validates_inclusion_of on generated message #{name}" do
      person_class.validates_inclusion_of :title, validation_options.merge(in: %w(a b c))
      @person.title = "z"
      call = [:title, :inclusion, @person, generate_message_options.merge(value: "z")]
      assert_called_with(ActiveModel::Error, :generate_message, call) do
        @person.valid?
        @person.errors.messages
      end
    end
  end

  COMMON_CASES.each do |name, validation_options, generate_message_options|
    test "validates_inclusion_of using :within on generated message #{name}" do
      person_class.validates_inclusion_of :title, validation_options.merge(within: %w(a b c))
      @person.title = "z"
      call = [:title, :inclusion, @person, generate_message_options.merge(value: "z")]
      assert_called_with(ActiveModel::Error, :generate_message, call) do
        @person.valid?
        @person.errors.messages
      end
    end
  end

  COMMON_CASES.each do |name, validation_options, generate_message_options|
    test "validates_exclusion_of generated message #{name}" do
      person_class.validates_exclusion_of :title, validation_options.merge(in: %w(a b c))
      @person.title = "a"
      call = [:title, :exclusion, @person, generate_message_options.merge(value: "a")]
      assert_called_with(ActiveModel::Error, :generate_message, call) do
        @person.valid?
        @person.errors.messages
      end
    end
  end

  COMMON_CASES.each do |name, validation_options, generate_message_options|
    test "validates_exclusion_of using :within generated message #{name}" do
      person_class.validates_exclusion_of :title, validation_options.merge(within: %w(a b c))
      @person.title = "a"
      call = [:title, :exclusion, @person, generate_message_options.merge(value: "a")]
      assert_called_with(ActiveModel::Error, :generate_message, call) do
        @person.valid?
        @person.errors.messages
      end
    end
  end

  COMMON_CASES.each do |name, validation_options, generate_message_options|
    test "validates_numericality_of generated message #{name}" do
      person_class.validates_numericality_of :title, validation_options
      @person.title = "a"
      call = [:title, :not_a_number, @person, generate_message_options.merge(value: "a")]
      assert_called_with(ActiveModel::Error, :generate_message, call) do
        @person.valid?
        @person.errors.messages
      end
    end
  end

  COMMON_CASES.each do |name, validation_options, generate_message_options|
    test "validates_numericality_of for :only_integer on generated message #{name}" do
      person_class.validates_numericality_of :title, validation_options.merge(only_integer: true)
      @person.title = "0.0"
      call = [:title, :not_an_integer, @person, generate_message_options.merge(value: "0.0")]
      assert_called_with(ActiveModel::Error, :generate_message, call) do
        @person.valid?
        @person.errors.messages
      end
    end
  end

  COMMON_CASES.each do |name, validation_options, generate_message_options|
    test "validates_numericality_of for :odd on generated message #{name}" do
      person_class.validates_numericality_of :title, validation_options.merge(only_integer: true, odd: true)
      @person.title = 0
      call = [:title, :odd, @person, generate_message_options.merge(value: 0)]
      assert_called_with(ActiveModel::Error, :generate_message, call) do
        @person.valid?
        @person.errors.messages
      end
    end
  end

  COMMON_CASES.each do |name, validation_options, generate_message_options|
    test "validates_numericality_of for :less_than on generated message #{name}" do
      person_class.validates_numericality_of :title, validation_options.merge(only_integer: true, less_than: 0)
      @person.title = 1
      call = [:title, :less_than, @person, generate_message_options.merge(value: 1, count: 0)]
      assert_called_with(ActiveModel::Error, :generate_message, call) do
        @person.valid?
        @person.errors.messages
      end
    end
  end

  # To make things DRY this macro is created to define 3 tests for every validation case.
  def self.set_expectations_for_validation(validation, error_type, &block_that_sets_validation)
    if error_type == :confirmation
      attribute = :title_confirmation
    else
      attribute = :title
    end

    test "#{validation} finds custom model key translation when #{error_type}" do
      I18n.backend.store_translations "en", activemodel: { errors: { models: { person: { attributes: { attribute => { error_type => "custom message" } } } } } }
      I18n.backend.store_translations "en", errors: { messages: { error_type => "global message" } }

      yield(@person, {})
      @person.valid?
      assert_equal ["custom message"], @person.errors[attribute]
    end

    test "#{validation} finds custom model key translation with interpolation when #{error_type}" do
      I18n.backend.store_translations "en", activemodel: { errors: { models: { person: { attributes: { attribute => { error_type => "custom message with %{extra}" } } } } } }
      I18n.backend.store_translations "en", errors: { messages: { error_type => "global message" } }

      yield(@person, { extra: "extra information" })
      @person.valid?
      assert_equal ["custom message with extra information"], @person.errors[attribute]
    end

    test "#{validation} finds global default key translation when #{error_type}" do
      I18n.backend.store_translations "en", errors: { messages: { error_type => "global message" } }

      yield(@person, {})
      @person.valid?
      assert_equal ["global message"], @person.errors[attribute]
    end
  end

  set_expectations_for_validation "validates_confirmation_of", :confirmation do |person, options_to_merge|
    person.class.validates_confirmation_of :title, options_to_merge
    person.title_confirmation = "foo"
  end

  set_expectations_for_validation "validates_acceptance_of", :accepted do |person, options_to_merge|
    person.class.validates_acceptance_of :title, options_to_merge.merge(allow_nil: false)
  end

  set_expectations_for_validation "validates_presence_of", :blank do |person, options_to_merge|
    person.class.validates_presence_of :title, options_to_merge
  end

  set_expectations_for_validation "validates_length_of", :too_short do |person, options_to_merge|
    person.class.validates_length_of :title, options_to_merge.merge(within: 3..5)
  end

  set_expectations_for_validation "validates_length_of", :too_long do |person, options_to_merge|
    person.class.validates_length_of :title, options_to_merge.merge(within: 3..5)
    person.title = "too long"
  end

  set_expectations_for_validation "validates_length_of", :wrong_length do |person, options_to_merge|
    person.class.validates_length_of :title, options_to_merge.merge(is: 5)
  end

  set_expectations_for_validation "validates_format_of", :invalid do |person, options_to_merge|
    person.class.validates_format_of :title, options_to_merge.merge(with: /\A[1-9][0-9]*\z/)
  end

  set_expectations_for_validation "validates_inclusion_of", :inclusion do |person, options_to_merge|
    person.class.validates_inclusion_of :title, options_to_merge.merge(in: %w(a b c))
  end

  set_expectations_for_validation "validates_exclusion_of", :exclusion do |person, options_to_merge|
    person.class.validates_exclusion_of :title, options_to_merge.merge(in: %w(a b c))
    person.title = "a"
  end

  set_expectations_for_validation "validates_numericality_of", :not_a_number do |person, options_to_merge|
    person.class.validates_numericality_of :title, options_to_merge
    person.title = "a"
  end

  set_expectations_for_validation "validates_numericality_of", :not_an_integer do |person, options_to_merge|
    person.class.validates_numericality_of :title, options_to_merge.merge(only_integer: true)
    person.title = "1.0"
  end

  set_expectations_for_validation "validates_numericality_of", :odd do |person, options_to_merge|
    person.class.validates_numericality_of :title, options_to_merge.merge(only_integer: true, odd: true)
    person.title = 0
  end

  set_expectations_for_validation "validates_numericality_of", :less_than do |person, options_to_merge|
    person.class.validates_numericality_of :title, options_to_merge.merge(only_integer: true, less_than: 0)
    person.title = 1
  end

  def test_validations_with_message_symbol_must_translate
    I18n.backend.store_translations "en", errors: { messages: { custom_error: "I am a custom error" } }
    person_class.validates_presence_of :title, message: :custom_error
    @person.title = nil
    @person.valid?
    assert_equal ["I am a custom error"], @person.errors[:title]
  end

  def test_validates_with_message_symbol_must_translate_per_attribute
    I18n.backend.store_translations "en", activemodel: { errors: { models: { person: { attributes: { title: { custom_error: "I am a custom error" } } } } } }
    person_class.validates_presence_of :title, message: :custom_error
    @person.title = nil
    @person.valid?
    assert_equal ["I am a custom error"], @person.errors[:title]
  end

  def test_validates_with_message_symbol_must_translate_per_model
    I18n.backend.store_translations "en", activemodel: { errors: { models: { person: { custom_error: "I am a custom error" } } } }
    person_class.validates_presence_of :title, message: :custom_error
    @person.title = nil
    @person.valid?
    assert_equal ["I am a custom error"], @person.errors[:title]
  end

  def test_validates_with_message_string
    person_class.validates_presence_of :title, message: "I am a custom error"
    @person.title = nil
    @person.valid?
    assert_equal ["I am a custom error"], @person.errors[:title]
  end

  def person_class
    @person_stub ||= self.class.const_set(:Person, Class.new(Person))
  end
end

immutable_string.rb

# frozen_string_literal: true

module ActiveModel
  module Type
    # Attribute type to represent immutable strings. It casts incoming values to
    # frozen strings.
    #
    #   class Person
    #     include ActiveModel::Attributes
    #
    #     attribute :name, :immutable_string
    #   end
    #
    #   person = Person.new
    #   person.name = 1
    #
    #   person.name # => "1"
    #   person.name.frozen? # => true
    #
    # Values are coerced to strings using their +to_s+ method. Boolean values
    # are treated differently, however: +true+ will be cast to <tt>"t"</tt> and
    # +false+ will be cast to <tt>"f"</tt>. These strings can be customized when
    # declaring an attribute:
    #
    #   class Person
    #     include ActiveModel::Attributes
    #
    #     attribute :active, :immutable_string, true: "aye", false: "nay"
    #   end
    #
    #   person = Person.new
    #   person.active = true
    #
    #   person.active # => "aye"
    class ImmutableString < Value
      def initialize(**args)
        @true  = -(args.delete(:true)&.to_s  || "t")
        @false = -(args.delete(:false)&.to_s || "f")
        super
      end

      def type
        :string
      end

      def serialize(value)
        case value
        when ::Numeric, ::Symbol, ActiveSupport::Duration then value.to_s
        when true then @true
        when false then @false
        else super
        end
      end

      private
        def cast_value(value)
          case value
          when true then @true
          when false then @false
          else value.to_s.freeze
          end
        end
    end
  end
end

immutable_string_test.rb

# frozen_string_literal: true

require "cases/helper"

module ActiveModel
  module Type
    class ImmutableStringTest < ActiveModel::TestCase
      test "cast strings are frozen" do
        s = "foo"
        type = Type::ImmutableString.new
        assert_equal true, type.cast(s).frozen?
      end

      test "immutable strings are not duped coming out" do
        s = "foo"
        type = Type::ImmutableString.new
        assert_same s, type.cast(s)
        assert_same s, type.deserialize(s)
      end
    end
  end
end

inclusion.rb

# frozen_string_literal: true

require "active_model/validations/clusivity"

module ActiveModel
  module Validations
    class InclusionValidator < EachValidator # :nodoc:
      include Clusivity

      def validate_each(record, attribute, value)
        unless include?(record, value)
          record.errors.add(attribute, :inclusion, **options.except(:in, :within).merge!(value: value))
        end
      end
    end

    module HelperMethods
      # Validates whether the value of the specified attribute is available in a
      # particular enumerable object.
      #
      #   class Person < ActiveRecord::Base
      #     validates_inclusion_of :role, in: %w( admin contributor )
      #     validates_inclusion_of :age, in: 0..99
      #     validates_inclusion_of :format, in: %w( jpg gif png ), message: "extension %{value} is not included in the list"
      #     validates_inclusion_of :states, in: ->(person) { STATES[person.country] }
      #     validates_inclusion_of :karma, in: :available_karmas
      #   end
      #
      # Configuration options:
      # * <tt>:in</tt> - An enumerable object of available items. This can be
      #   supplied as a proc, lambda, or symbol which returns an enumerable. If the
      #   enumerable is a numerical, time, or datetime range the test is performed
      #   with <tt>Range#cover?</tt>, otherwise with <tt>include?</tt>. When using
      #   a proc or lambda the instance under validation is passed as an argument.
      # * <tt>:within</tt> - A synonym(or alias) for <tt>:in</tt>
      # * <tt>:message</tt> - Specifies a custom error message (default is: "is
      #   not included in the list").
      #
      # There is also a list of default options supported by every validator:
      # +:if+, +:unless+, +:on+, +:allow_nil+, +:allow_blank+, and +:strict+.
      # See ActiveModel::Validations::ClassMethods#validates for more information.
      def validates_inclusion_of(*attr_names)
        validates_with InclusionValidator, _merge_attributes(attr_names)
      end
    end
  end
end

inclusion_validation_test.rb

# frozen_string_literal: true

require "cases/helper"

require "models/topic"
require "models/person"

class InclusionValidationTest < ActiveModel::TestCase
  def teardown
    Topic.clear_validators!
  end

  def test_validates_inclusion_of_range
    Topic.validates_inclusion_of(:title, in: "aaa".."bbb")
    assert_predicate Topic.new("title" => "bbc", "content" => "abc"), :invalid?
    assert_predicate Topic.new("title" => "aa", "content" => "abc"), :invalid?
    assert_predicate Topic.new("title" => "aaab", "content" => "abc"), :invalid?
    assert_predicate Topic.new("title" => "aaa", "content" => "abc"), :valid?
    assert_predicate Topic.new("title" => "abc", "content" => "abc"), :valid?
    assert_predicate Topic.new("title" => "bbb", "content" => "abc"), :valid?
  end

  def test_validates_inclusion_of_time_range
    range_begin = 1.year.ago
    range_end = Time.now
    Topic.validates_inclusion_of(:created_at, in: range_begin..range_end)
    assert_predicate Topic.new(title: "aaa", created_at: 2.years.ago), :invalid?
    assert_predicate Topic.new(title: "aaa", created_at: 3.months.ago), :valid?
    assert_predicate Topic.new(title: "aaa", created_at: 37.weeks.from_now), :invalid?
    assert_predicate Topic.new(title: "aaa", created_at: range_begin), :valid?
    assert_predicate Topic.new(title: "aaa", created_at: range_end), :valid?
  end

  def test_validates_inclusion_of_date_range
    range_begin = 1.year.until(Date.today)
    range_end = Date.today
    Topic.validates_inclusion_of(:created_at, in: range_begin..range_end)
    assert_predicate Topic.new(title: "aaa", created_at: 2.years.until(Date.today)), :invalid?
    assert_predicate Topic.new(title: "aaa", created_at: 3.months.until(Date.today)), :valid?
    assert_predicate Topic.new(title: "aaa", created_at: 37.weeks.since(Date.today)), :invalid?
    assert_predicate Topic.new(title: "aaa", created_at: 1.year.until(Date.today)), :valid?
    assert_predicate Topic.new(title: "aaa", created_at: Date.today), :valid?
    assert_predicate Topic.new(title: "aaa", created_at: range_begin), :valid?
    assert_predicate Topic.new(title: "aaa", created_at: range_end), :valid?
  end

  def test_validates_inclusion_of_date_time_range
    range_begin = 1.year.until(DateTime.current)
    range_end = DateTime.current
    Topic.validates_inclusion_of(:created_at, in: range_begin..range_end)
    assert_predicate Topic.new(title: "aaa", created_at: 2.years.until(DateTime.current)), :invalid?
    assert_predicate Topic.new(title: "aaa", created_at: 3.months.until(DateTime.current)), :valid?
    assert_predicate Topic.new(title: "aaa", created_at: 37.weeks.since(DateTime.current)), :invalid?
    assert_predicate Topic.new(title: "aaa", created_at: range_begin), :valid?
    assert_predicate Topic.new(title: "aaa", created_at: range_end), :valid?
  end

  def test_validates_inclusion_of
    Topic.validates_inclusion_of(:title, in: %w( a b c d e f g ))

    assert_predicate Topic.new("title" => "a!", "content" => "abc"), :invalid?
    assert_predicate Topic.new("title" => "a b", "content" => "abc"), :invalid?
    assert_predicate Topic.new("title" => nil, "content" => "def"), :invalid?

    t = Topic.new("title" => "a", "content" => "I know you are but what am I?")
    assert_predicate t, :valid?
    t.title = "uhoh"
    assert_predicate t, :invalid?
    assert_predicate t.errors[:title], :any?
    assert_equal ["is not included in the list"], t.errors[:title]

    assert_raise(ArgumentError) { Topic.validates_inclusion_of(:title, in: nil) }
    assert_raise(ArgumentError) { Topic.validates_inclusion_of(:title, in: 0) }

    assert_nothing_raised { Topic.validates_inclusion_of(:title, in: "hi!") }
    assert_nothing_raised { Topic.validates_inclusion_of(:title, in: {}) }
    assert_nothing_raised { Topic.validates_inclusion_of(:title, in: []) }
  end

  def test_validates_inclusion_of_with_allow_nil
    Topic.validates_inclusion_of(:title, in: %w( a b c d e f g ), allow_nil: true)

    assert_predicate Topic.new("title" => "a!", "content" => "abc"), :invalid?
    assert_predicate Topic.new("title" => "",   "content" => "abc"), :invalid?
    assert_predicate Topic.new("title" => nil,  "content" => "abc"), :valid?
  end

  def test_validates_inclusion_of_with_formatted_message
    Topic.validates_inclusion_of(:title, in: %w( a b c d e f g ), message: "option %{value} is not in the list")

    assert_predicate Topic.new("title" => "a", "content" => "abc"), :valid?

    t = Topic.new("title" => "uhoh", "content" => "abc")
    assert_predicate t, :invalid?
    assert_predicate t.errors[:title], :any?
    assert_equal ["option uhoh is not in the list"], t.errors[:title]
  end

  def test_validates_inclusion_of_with_within_option
    Topic.validates_inclusion_of(:title, within: %w( a b c d e f g ))

    assert_predicate Topic.new("title" => "a", "content" => "abc"), :valid?

    t = Topic.new("title" => "uhoh", "content" => "abc")
    assert_predicate t, :invalid?
    assert_predicate t.errors[:title], :any?
  end

  def test_validates_inclusion_of_for_ruby_class
    Person.validates_inclusion_of :karma, in: %w( abe monkey )

    p = Person.new
    p.karma = "Lifo"
    assert_predicate p, :invalid?

    assert_equal ["is not included in the list"], p.errors[:karma]

    p.karma = "monkey"
    assert_predicate p, :valid?
  ensure
    Person.clear_validators!
  end

  def test_validates_inclusion_of_with_lambda
    Topic.validates_inclusion_of :title, in: lambda { |topic| topic.author_name == "sikachu" ? %w( monkey elephant ) : %w( abe wasabi ) }

    t = Topic.new
    t.title = "wasabi"
    t.author_name = "sikachu"
    assert_predicate t, :invalid?

    t.title = "elephant"
    assert_predicate t, :valid?
  end

  def test_validates_inclusion_of_with_symbol
    Person.validates_inclusion_of :karma, in: :available_karmas

    p = Person.new
    p.karma = "Lifo"

    def p.available_karmas
      %w()
    end

    assert_predicate p, :invalid?
    assert_equal ["is not included in the list"], p.errors[:karma]

    p = Person.new
    p.karma = "Lifo"

    def p.available_karmas
      %w(Lifo)
    end

    assert_predicate p, :valid?
  ensure
    Person.clear_validators!
  end

  def test_validates_inclusion_of_with_array_value
    Person.validates_inclusion_of :karma, in: %w( abe monkey )

    p = Person.new
    p.karma = %w(Lifo monkey)

    assert p.invalid?
    assert_equal ["is not included in the list"], p.errors[:karma]

    p = Person.new
    p.karma = %w(abe monkey)

    assert p.valid?
  ensure
    Person.clear_validators!
  end
end

integer.rb

# frozen_string_literal: true

module ActiveModel
  module Type
    # Attribute type for integer representation. This type is registered under
    # the +:integer+ key.
    #
    #   class Person
    #     include ActiveModel::Attributes
    #
    #     attribute :age, :integer
    #   end
    #
    #   person = Person.new
    #   person.age = "18"
    #
    #   person.age # => 18
    #
    # Values are cast using their +to_i+ method, if it exists. If it does not
    # exist, or if it raises an error, the value will be cast to +nil+:
    #
    #   person.age = :not_an_integer
    #   person.age # => nil (because Symbol does not define #to_i)
    #
    # Serialization also works under the same principle. Non-numeric strings are
    # serialized as +nil+, for example.
    #
    # Serialization also validates that the integer can be stored using a
    # limited number of bytes. If it cannot, an ActiveModel::RangeError will be
    # raised. The default limit is 4 bytes, and can be customized when declaring
    # an attribute:
    #
    #   class Person
    #     include ActiveModel::Attributes
    #
    #     attribute :age, :integer, limit: 6
    #   end
    class Integer < Value
      include Helpers::Numeric

      # Column storage size in bytes.
      # 4 bytes means an integer as opposed to smallint etc.
      DEFAULT_LIMIT = 4

      def initialize(**)
        super
        @range = min_value...max_value
      end

      def type
        :integer
      end

      def deserialize(value)
        return if value.blank?
        value.to_i
      end

      def serialize(value)
        return if value.is_a?(::String) && non_numeric_string?(value)
        ensure_in_range(super)
      end

      def serializable?(value)
        cast_value = cast(value)
        in_range?(cast_value) || begin
          yield cast_value if block_given?
          false
        end
      end

      private
        attr_reader :range

        def in_range?(value)
          !value || range.member?(value)
        end

        def cast_value(value)
          value.to_i rescue nil
        end

        def ensure_in_range(value)
          unless in_range?(value)
            raise ActiveModel::RangeError, "#{value} is out of range for #{self.class} with limit #{_limit} bytes"
          end
          value
        end

        def max_value
          1 << (_limit * 8 - 1) # 8 bits per byte with one bit for sign
        end

        def min_value
          -max_value
        end

        def _limit
          limit || DEFAULT_LIMIT
        end
    end
  end
end

integer_test.rb

# frozen_string_literal: true

require "cases/helper"
require "active_support/core_ext/numeric/time"

module ActiveModel
  module Type
    class IntegerTest < ActiveModel::TestCase
      test "simple values" do
        type = Type::Integer.new
        assert_nil type.cast("")
        assert_equal 1, type.cast(1)
        assert_equal 1, type.cast("1")
        assert_equal 1, type.cast("1ignore")
        assert_equal 0, type.cast("bad1")
        assert_equal 0, type.cast("bad")
        assert_equal 1, type.cast(1.7)
        assert_equal 0, type.cast(false)
        assert_equal 1, type.cast(true)
        assert_nil type.cast(nil)
      end

      test "random objects cast to nil" do
        type = Type::Integer.new
        assert_nil type.cast([1, 2])
        assert_nil type.cast(1 => 2)
        assert_nil type.cast(1..2)
      end

      test "casting objects without to_i" do
        type = Type::Integer.new
        assert_nil type.cast(::Object.new)
      end

      test "casting nan and infinity" do
        type = Type::Integer.new
        assert_nil type.cast(::Float::NAN)
        assert_nil type.cast(1.0 / 0.0)
      end

      test "casting booleans for database" do
        type = Type::Integer.new
        assert_equal 1, type.serialize(true)
        assert_equal 0, type.serialize(false)
      end

      test "casting duration" do
        type = Type::Integer.new
        assert_equal 1800, type.cast(30.minutes)
        assert_equal 7200, type.cast(2.hours)
      end

      test "casting string for database" do
        type = Type::Integer.new
        assert_nil type.serialize("wibble")
        assert_equal 5, type.serialize("5wibble")
        assert_equal 5, type.serialize(" +5")
        assert_equal(-5, type.serialize(" -5"))
      end

      test "casting empty string" do
        type = Type::Integer.new
        assert_nil type.cast("")
        assert_nil type.serialize("")
        assert_nil type.deserialize("")
      end

      test "changed?" do
        type = Type::Integer.new

        assert type.changed?(0, 0, "wibble")
        assert type.changed?(5, 0, "wibble")
        assert_not type.changed?(5, 5, "5wibble")
        assert_not type.changed?(5, 5, "5")
        assert_not type.changed?(5, 5, "5.0")
        assert_not type.changed?(5, 5, "+5")
        assert_not type.changed?(5, 5, "+5.0")
        assert_not type.changed?(-5, -5, "-5")
        assert_not type.changed?(-5, -5, "-5.0")
        assert_not type.changed?(nil, nil, nil)
      end

      test "values below int min value are out of range" do
        assert_raises(ActiveModel::RangeError) do
          Integer.new.serialize(-2147483649)
        end
      end

      test "values above int max value are out of range" do
        assert_raises(ActiveModel::RangeError) do
          Integer.new.serialize(2147483648)
        end
      end

      test "very small numbers are out of range" do
        assert_raises(ActiveModel::RangeError) do
          Integer.new.serialize(-9999999999999999999999999999999)
        end
      end

      test "very large numbers are out of range" do
        assert_raises(ActiveModel::RangeError) do
          Integer.new.serialize(9999999999999999999999999999999)
        end
      end

      test "normal numbers are in range" do
        type = Integer.new
        assert_equal(0, type.serialize(0))
        assert_equal(-1, type.serialize(-1))
        assert_equal(1, type.serialize(1))
      end

      test "int max value is in range" do
        assert_equal(2147483647, Integer.new.serialize(2147483647))
      end

      test "int min value is in range" do
        assert_equal(-2147483648, Integer.new.serialize(-2147483648))
      end

      test "columns with a larger limit have larger ranges" do
        type = Integer.new(limit: 8)

        assert_equal(9223372036854775807, type.serialize(9223372036854775807))
        assert_equal(-9223372036854775808, type.serialize(-9223372036854775808))
        assert_raises(ActiveModel::RangeError) do
          type.serialize(-9999999999999999999999999999999)
        end
        assert_raises(ActiveModel::RangeError) do
          type.serialize(9999999999999999999999999999999)
        end
      end
    end
  end
end

json.rb

# frozen_string_literal: true

require "active_support/json"

module ActiveModel
  module Serializers
    # == Active \Model \JSON \Serializer
    module JSON
      extend ActiveSupport::Concern
      include ActiveModel::Serialization

      included do
        extend ActiveModel::Naming

        class_attribute :include_root_in_json, instance_writer: false, default: false
      end

      # Returns a hash representing the model. Some configuration can be
      # passed through +options+.
      #
      # The option <tt>include_root_in_json</tt> controls the top-level behavior
      # of +as_json+. If +true+, +as_json+ will emit a single root node named
      # after the object's type. The default value for <tt>include_root_in_json</tt>
      # option is +false+.
      #
      #   user = User.find(1)
      #   user.as_json
      #   # => { "id" => 1, "name" => "Konata Izumi", "age" => 16,
      #   #     "created_at" => "2006-08-01T17:27:133.000Z", "awesome" => true}
      #
      #   ActiveRecord::Base.include_root_in_json = true
      #
      #   user.as_json
      #   # => { "user" => { "id" => 1, "name" => "Konata Izumi", "age" => 16,
      #   #                  "created_at" => "2006-08-01T17:27:13.000Z", "awesome" => true } }
      #
      # This behavior can also be achieved by setting the <tt>:root</tt> option
      # to +true+ as in:
      #
      #   user = User.find(1)
      #   user.as_json(root: true)
      #   # => { "user" => { "id" => 1, "name" => "Konata Izumi", "age" => 16,
      #   #                  "created_at" => "2006-08-01T17:27:13.000Z", "awesome" => true } }
      #
      # If you prefer, <tt>:root</tt> may also be set to a custom string key instead as in:
      #
      #   user = User.find(1)
      #   user.as_json(root: "author")
      #   # => { "author" => { "id" => 1, "name" => "Konata Izumi", "age" => 16,
      #   #                  "created_at" => "2006-08-01T17:27:13.000Z", "awesome" => true } }
      #
      # Without any +options+, the returned Hash will include all the model's
      # attributes.
      #
      #   user = User.find(1)
      #   user.as_json
      #   # => { "id" => 1, "name" => "Konata Izumi", "age" => 16,
      #   #      "created_at" => "2006-08-01T17:27:13.000Z", "awesome" => true}
      #
      # The <tt>:only</tt> and <tt>:except</tt> options can be used to limit
      # the attributes included, and work similar to the +attributes+ method.
      #
      #   user.as_json(only: [:id, :name])
      #   # => { "id" => 1, "name" => "Konata Izumi" }
      #
      #   user.as_json(except: [:id, :created_at, :age])
      #   # => { "name" => "Konata Izumi", "awesome" => true }
      #
      # To include the result of some method calls on the model use <tt>:methods</tt>:
      #
      #   user.as_json(methods: :permalink)
      #   # => { "id" => 1, "name" => "Konata Izumi", "age" => 16,
      #   #      "created_at" => "2006-08-01T17:27:13.000Z", "awesome" => true,
      #   #      "permalink" => "1-konata-izumi" }
      #
      # To include associations use <tt>:include</tt>:
      #
      #   user.as_json(include: :posts)
      #   # => { "id" => 1, "name" => "Konata Izumi", "age" => 16,
      #   #      "created_at" => "2006-08-01T17:27:13.000Z", "awesome" => true,
      #   #      "posts" => [ { "id" => 1, "author_id" => 1, "title" => "Welcome to the weblog" },
      #   #                   { "id" => 2, "author_id" => 1, "title" => "So I was thinking" } ] }
      #
      # Second level and higher order associations work as well:
      #
      #   user.as_json(include: { posts: {
      #                              include: { comments: {
      #                                             only: :body } },
      #                              only: :title } })
      #   # => { "id" => 1, "name" => "Konata Izumi", "age" => 16,
      #   #      "created_at" => "2006-08-01T17:27:13.000Z", "awesome" => true,
      #   #      "posts" => [ { "comments" => [ { "body" => "1st post!" }, { "body" => "Second!" } ],
      #   #                     "title" => "Welcome to the weblog" },
      #   #                   { "comments" => [ { "body" => "Don't think too hard" } ],
      #   #                     "title" => "So I was thinking" } ] }
      def as_json(options = nil)
        root = if options && options.key?(:root)
          options[:root]
        else
          include_root_in_json
        end

        hash = serializable_hash(options).as_json
        if root
          root = model_name.element if root == true
          { root => hash }
        else
          hash
        end
      end

      # Sets the model +attributes+ from a JSON string. Returns +self+.
      #
      #   class Person
      #     include ActiveModel::Serializers::JSON
      #
      #     attr_accessor :name, :age, :awesome
      #
      #     def attributes=(hash)
      #       hash.each do |key, value|
      #         send("#{key}=", value)
      #       end
      #     end
      #
      #     def attributes
      #       instance_values
      #     end
      #   end
      #
      #   json = { name: 'bob', age: 22, awesome:true }.to_json
      #   person = Person.new
      #   person.from_json(json) # => #<Person:0x007fec5e7a0088 @age=22, @awesome=true, @name="bob">
      #   person.name            # => "bob"
      #   person.age             # => 22
      #   person.awesome         # => true
      #
      # The default value for +include_root+ is +false+. You can change it to
      # +true+ if the given JSON string includes a single root node.
      #
      #   json = { person: { name: 'bob', age: 22, awesome:true } }.to_json
      #   person = Person.new
      #   person.from_json(json, true) # => #<Person:0x007fec5e7a0088 @age=22, @awesome=true, @name="bob">
      #   person.name                  # => "bob"
      #   person.age                   # => 22
      #   person.awesome               # => true
      def from_json(json, include_root = include_root_in_json)
        hash = ActiveSupport::JSON.decode(json)
        hash = hash.values.first if include_root
        self.attributes = hash
        self
      end
    end
  end
end

json_serialization_test.rb

# frozen_string_literal: true

require "cases/helper"
require "models/contact"
require "active_support/core_ext/object/instance_variables"

class JsonSerializationTest < ActiveModel::TestCase
  def setup
    @contact = Contact.new
    @contact.name = "Konata Izumi"
    @contact.age = 16
    @contact.created_at = Time.utc(2006, 8, 1)
    @contact.awesome = true
    @contact.preferences = { "shows" => "anime" }
  end

  test "should not include root in json (class method)" do
    json = @contact.to_json

    assert_no_match %r{^\{"contact":\{}, json
    assert_match %r{"name":"Konata Izumi"}, json
    assert_match %r{"age":16}, json
    assert_includes json, %("created_at":#{ActiveSupport::JSON.encode(Time.utc(2006, 8, 1))})
    assert_match %r{"awesome":true}, json
    assert_match %r{"preferences":\{"shows":"anime"\}}, json
  end

  test "should include root in json if include_root_in_json is true" do
    original_include_root_in_json = Contact.include_root_in_json
    Contact.include_root_in_json = true
    json = @contact.to_json

    assert_match %r{^\{"contact":\{}, json
    assert_match %r{"name":"Konata Izumi"}, json
    assert_match %r{"age":16}, json
    assert_includes json, %("created_at":#{ActiveSupport::JSON.encode(Time.utc(2006, 8, 1))})
    assert_match %r{"awesome":true}, json
    assert_match %r{"preferences":\{"shows":"anime"\}}, json
  ensure
    Contact.include_root_in_json = original_include_root_in_json
  end

  test "should include root in json (option) even if the default is set to false" do
    json = @contact.to_json(root: true)

    assert_match %r{^\{"contact":\{}, json
  end

  test "should not include root in json (option)" do
    json = @contact.to_json(root: false)

    assert_no_match %r{^\{"contact":\{}, json
  end

  test "should include custom root in json" do
    json = @contact.to_json(root: "json_contact")

    assert_match %r{^\{"json_contact":\{}, json
    assert_match %r{"name":"Konata Izumi"}, json
    assert_match %r{"age":16}, json
    assert_includes json, %("created_at":#{ActiveSupport::JSON.encode(Time.utc(2006, 8, 1))})
    assert_match %r{"awesome":true}, json
    assert_match %r{"preferences":\{"shows":"anime"\}}, json
  end

  test "should encode all encodable attributes" do
    json = @contact.to_json

    assert_match %r{"name":"Konata Izumi"}, json
    assert_match %r{"age":16}, json
    assert_includes json, %("created_at":#{ActiveSupport::JSON.encode(Time.utc(2006, 8, 1))})
    assert_match %r{"awesome":true}, json
    assert_match %r{"preferences":\{"shows":"anime"\}}, json
  end

  test "should allow attribute filtering with only" do
    json = @contact.to_json(only: [:name, :age])

    assert_match %r{"name":"Konata Izumi"}, json
    assert_match %r{"age":16}, json
    assert_no_match %r{"awesome":true}, json
    assert_not_includes json, %("created_at":#{ActiveSupport::JSON.encode(Time.utc(2006, 8, 1))})
    assert_no_match %r{"preferences":\{"shows":"anime"\}}, json
  end

  test "should allow attribute filtering with except" do
    json = @contact.to_json(except: [:name, :age])

    assert_no_match %r{"name":"Konata Izumi"}, json
    assert_no_match %r{"age":16}, json
    assert_match %r{"awesome":true}, json
    assert_includes json, %("created_at":#{ActiveSupport::JSON.encode(Time.utc(2006, 8, 1))})
    assert_match %r{"preferences":\{"shows":"anime"\}}, json
  end

  test "methods are called on object" do
    # Define methods on fixture.
    def @contact.label; "Has cheezburger"; end
    def @contact.favorite_quote; "Constraints are liberating"; end

    # Single method.
    assert_match %r{"label":"Has cheezburger"}, @contact.to_json(only: :name, methods: :label)

    # Both methods.
    methods_json = @contact.to_json(only: :name, methods: [:label, :favorite_quote])
    assert_match %r{"label":"Has cheezburger"}, methods_json
    assert_match %r{"favorite_quote":"Constraints are liberating"}, methods_json
  end

  test "should return Hash for errors" do
    contact = Contact.new
    contact.errors.add :name, "can't be blank"
    contact.errors.add :name, "is too short (minimum is 2 characters)"
    contact.errors.add :age, "must be 16 or over"

    hash = {}
    hash[:name] = ["can't be blank", "is too short (minimum is 2 characters)"]
    hash[:age]  = ["must be 16 or over"]
    assert_equal hash.to_json, contact.errors.to_json
  end

  test "serializable_hash should not modify options passed in argument" do
    options = { except: :name }
    @contact.serializable_hash(options)

    assert_nil options[:only]
    assert_equal :name, options[:except]
  end

  test "as_json should serialize timestamps" do
    assert_equal "2006-08-01T00:00:00.000Z", @contact.as_json["created_at"]
  end

  test "as_json should return a hash if include_root_in_json is true" do
    original_include_root_in_json = Contact.include_root_in_json
    Contact.include_root_in_json = true
    json = @contact.as_json

    assert_kind_of Hash, json
    assert_kind_of Hash, json["contact"]
    %w(name age created_at awesome preferences).each do |field|
      assert_equal @contact.public_send(field).as_json, json["contact"][field]
    end
  ensure
    Contact.include_root_in_json = original_include_root_in_json
  end

  test "from_json should work without a root (class attribute)" do
    json = @contact.to_json
    result = Contact.new.from_json(json)

    assert_equal result.name, @contact.name
    assert_equal result.age, @contact.age
    assert_equal Time.parse(result.created_at), @contact.created_at
    assert_equal result.awesome, @contact.awesome
    assert_equal result.preferences, @contact.preferences
  end

  test "from_json should work without a root (method parameter)" do
    json = @contact.to_json
    result = Contact.new.from_json(json, false)

    assert_equal result.name, @contact.name
    assert_equal result.age, @contact.age
    assert_equal Time.parse(result.created_at), @contact.created_at
    assert_equal result.awesome, @contact.awesome
    assert_equal result.preferences, @contact.preferences
  end

  test "from_json should work with a root (method parameter)" do
    json = @contact.to_json(root: :true)
    result = Contact.new.from_json(json, true)

    assert_equal result.name, @contact.name
    assert_equal result.age, @contact.age
    assert_equal Time.parse(result.created_at), @contact.created_at
    assert_equal result.awesome, @contact.awesome
    assert_equal result.preferences, @contact.preferences
  end

  test "custom as_json should be honored when generating json" do
    def @contact.as_json(options); { name: name, created_at: created_at }; end
    json = @contact.to_json

    assert_match %r{"name":"Konata Izumi"}, json
    assert_match %r{"created_at":#{ActiveSupport::JSON.encode(Time.utc(2006, 8, 1))}}, json
    assert_no_match %r{"awesome":}, json
    assert_no_match %r{"preferences":}, json
  end

  test "custom as_json options should be extensible" do
    def @contact.as_json(options = {}); super(options.merge(only: [:name])); end
    json = @contact.to_json

    assert_match %r{"name":"Konata Izumi"}, json
    assert_no_match %r{"created_at":#{ActiveSupport::JSON.encode(Time.utc(2006, 8, 1))}}, json
    assert_no_match %r{"awesome":}, json
    assert_no_match %r{"preferences":}, json
  end

  test "Class.model_name should be json encodable" do
    assert_match %r{"Contact"}, Contact.model_name.to_json
  end
end

length.rb

# frozen_string_literal: true

module ActiveModel
  module Validations
    class LengthValidator < EachValidator # :nodoc:
      MESSAGES  = { is: :wrong_length, minimum: :too_short, maximum: :too_long }.freeze
      CHECKS    = { is: :==, minimum: :>=, maximum: :<= }.freeze

      RESERVED_OPTIONS = [:minimum, :maximum, :within, :is, :too_short, :too_long]

      def initialize(options)
        if range = (options.delete(:in) || options.delete(:within))
          raise ArgumentError, ":in and :within must be a Range" unless range.is_a?(Range)
          options[:minimum], options[:maximum] = range.min, range.max
        end

        if options[:allow_blank] == false && options[:minimum].nil? && options[:is].nil?
          options[:minimum] = 1
        end

        super
      end

      def check_validity!
        keys = CHECKS.keys & options.keys

        if keys.empty?
          raise ArgumentError, "Range unspecified. Specify the :in, :within, :maximum, :minimum, or :is option."
        end

        keys.each do |key|
          value = options[key]

          unless (value.is_a?(Integer) && value >= 0) || value == Float::INFINITY || value.is_a?(Symbol) || value.is_a?(Proc)
            raise ArgumentError, ":#{key} must be a non-negative Integer, Infinity, Symbol, or Proc"
          end
        end
      end

      def validate_each(record, attribute, value)
        value_length = value.respond_to?(:length) ? value.length : value.to_s.length
        errors_options = options.except(*RESERVED_OPTIONS)

        CHECKS.each do |key, validity_check|
          next unless check_value = options[key]

          if !value.nil? || skip_nil_check?(key)
            case check_value
            when Proc
              check_value = check_value.call(record)
            when Symbol
              check_value = record.send(check_value)
            end
            next if value_length.public_send(validity_check, check_value)
          end

          errors_options[:count] = check_value

          default_message = options[MESSAGES[key]]
          errors_options[:message] ||= default_message if default_message

          record.errors.add(attribute, MESSAGES[key], **errors_options)
        end
      end

      private
        def skip_nil_check?(key)
          key == :maximum && options[:allow_nil].nil? && options[:allow_blank].nil?
        end
    end

    module HelperMethods
      # Validates that the specified attributes match the length restrictions
      # supplied. Only one constraint option can be used at a time apart from
      # +:minimum+ and +:maximum+ that can be combined together:
      #
      #   class Person < ActiveRecord::Base
      #     validates_length_of :first_name, maximum: 30
      #     validates_length_of :last_name, maximum: 30, message: "less than 30 if you don't mind"
      #     validates_length_of :fax, in: 7..32, allow_nil: true
      #     validates_length_of :phone, in: 7..32, allow_blank: true
      #     validates_length_of :user_name, within: 6..20, too_long: 'pick a shorter name', too_short: 'pick a longer name'
      #     validates_length_of :zip_code, minimum: 5, too_short: 'please enter at least 5 characters'
      #     validates_length_of :smurf_leader, is: 4, message: "papa is spelled with 4 characters... don't play me."
      #     validates_length_of :words_in_essay, minimum: 100, too_short: 'Your essay must be at least 100 words.'
      #
      #     private
      #
      #     def words_in_essay
      #       essay.scan(/\w+/)
      #     end
      #   end
      #
      # Constraint options:
      #
      # * <tt>:minimum</tt> - The minimum size of the attribute.
      # * <tt>:maximum</tt> - The maximum size of the attribute. Allows +nil+ by
      #   default if not used with +:minimum+.
      # * <tt>:is</tt> - The exact size of the attribute.
      # * <tt>:within</tt> - A range specifying the minimum and maximum size of
      #   the attribute.
      # * <tt>:in</tt> - A synonym (or alias) for <tt>:within</tt>.
      #
      # Other options:
      #
      # * <tt>:allow_nil</tt> - Attribute may be +nil+; skip validation.
      # * <tt>:allow_blank</tt> - Attribute may be blank; skip validation.
      # * <tt>:too_long</tt> - The error message if the attribute goes over the
      #   maximum (default is: "is too long (maximum is %{count} characters)").
      # * <tt>:too_short</tt> - The error message if the attribute goes under the
      #   minimum (default is: "is too short (minimum is %{count} characters)").
      # * <tt>:wrong_length</tt> - The error message if using the <tt>:is</tt>
      #   method and the attribute is the wrong size (default is: "is the wrong
      #   length (should be %{count} characters)").
      # * <tt>:message</tt> - The error message to use for a <tt>:minimum</tt>,
      #   <tt>:maximum</tt>, or <tt>:is</tt> violation. An alias of the appropriate
      #   <tt>too_long</tt>/<tt>too_short</tt>/<tt>wrong_length</tt> message.
      #
      # There is also a list of default options supported by every validator:
      # +:if+, +:unless+, +:on+, and +:strict+.
      # See ActiveModel::Validations::ClassMethods#validates for more information.
      def validates_length_of(*attr_names)
        validates_with LengthValidator, _merge_attributes(attr_names)
      end

      alias_method :validates_size_of, :validates_length_of
    end
  end
end

length_validation_test.rb

# frozen_string_literal: true

require "cases/helper"

require "models/topic"
require "models/person"

class LengthValidationTest < ActiveModel::TestCase
  def teardown
    Topic.clear_validators!
  end

  def test_validates_length_of_with_allow_nil
    Topic.validates_length_of(:title, is: 5, allow_nil: true)

    assert_predicate Topic.new("title" => "ab"), :invalid?
    assert_predicate Topic.new("title" => ""), :invalid?
    assert_predicate Topic.new("title" => nil), :valid?
    assert_predicate Topic.new("title" => "abcde"), :valid?
  end

  def test_validates_length_of_with_allow_blank
    Topic.validates_length_of(:title, is: 5, allow_blank: true)

    assert_predicate Topic.new("title" => "ab"), :invalid?
    assert_predicate Topic.new("title" => ""), :valid?
    assert_predicate Topic.new("title" => nil), :valid?
    assert_predicate Topic.new("title" => "abcde"), :valid?
  end

  def test_validates_length_of_using_minimum
    Topic.validates_length_of :title, minimum: 5

    t = Topic.new("title" => "valid", "content" => "whatever")
    assert_predicate t, :valid?

    t.title = "not"
    assert_predicate t, :invalid?
    assert_predicate t.errors[:title], :any?
    assert_equal ["is too short (minimum is 5 characters)"], t.errors[:title]

    t.title = ""
    assert_predicate t, :invalid?
    assert_predicate t.errors[:title], :any?
    assert_equal ["is too short (minimum is 5 characters)"], t.errors[:title]

    t.title = nil
    assert_predicate t, :invalid?
    assert_predicate t.errors[:title], :any?
    assert_equal ["is too short (minimum is 5 characters)"], t.errors["title"]
  end

  def test_validates_length_of_using_maximum_should_allow_nil
    Topic.validates_length_of :title, maximum: 10
    t = Topic.new
    assert_predicate t, :valid?
  end

  def test_optionally_validates_length_of_using_minimum
    Topic.validates_length_of :title, minimum: 5, allow_nil: true

    t = Topic.new("title" => "valid", "content" => "whatever")
    assert_predicate t, :valid?

    t.title = nil
    assert_predicate t, :valid?
  end

  def test_validates_length_of_using_maximum
    Topic.validates_length_of :title, maximum: 5

    t = Topic.new("title" => "valid", "content" => "whatever")
    assert_predicate t, :valid?

    t.title = "notvalid"
    assert_predicate t, :invalid?
    assert_predicate t.errors[:title], :any?
    assert_equal ["is too long (maximum is 5 characters)"], t.errors[:title]

    t.title = ""
    assert_predicate t, :valid?
  end

  def test_optionally_validates_length_of_using_maximum
    Topic.validates_length_of :title, maximum: 5, allow_nil: true

    t = Topic.new("title" => "valid", "content" => "whatever")
    assert_predicate t, :valid?

    t.title = nil
    assert_predicate t, :valid?
  end

  def test_validates_length_of_using_within
    Topic.validates_length_of(:title, :content, within: 3..5)

    t = Topic.new("title" => "a!", "content" => "I'm ooooooooh so very long")
    assert_predicate t, :invalid?
    assert_equal ["is too short (minimum is 3 characters)"], t.errors[:title]
    assert_equal ["is too long (maximum is 5 characters)"], t.errors[:content]

    t.title = nil
    t.content = nil
    assert_predicate t, :invalid?
    assert_equal ["is too short (minimum is 3 characters)"], t.errors[:title]
    assert_equal ["is too short (minimum is 3 characters)"], t.errors[:content]

    t.title = "abe"
    t.content = "mad"
    assert_predicate t, :valid?
  end

  def test_validates_length_of_using_within_with_exclusive_range
    Topic.validates_length_of(:title, within: 4...10)

    t = Topic.new("title" => "9 chars!!")
    assert_predicate t, :valid?

    t.title = "Now I'm 10"
    assert_predicate t, :invalid?
    assert_equal ["is too long (maximum is 9 characters)"], t.errors[:title]

    t.title = "Four"
    assert_predicate t, :valid?
  end

  def test_optionally_validates_length_of_using_within
    Topic.validates_length_of :title, :content, within: 3..5, allow_nil: true

    t = Topic.new("title" => "abc", "content" => "abcd")
    assert_predicate t, :valid?

    t.title = nil
    assert_predicate t, :valid?
  end

  def test_validates_length_of_using_is
    Topic.validates_length_of :title, is: 5

    t = Topic.new("title" => "valid", "content" => "whatever")
    assert_predicate t, :valid?

    t.title = "notvalid"
    assert_predicate t, :invalid?
    assert_predicate t.errors[:title], :any?
    assert_equal ["is the wrong length (should be 5 characters)"], t.errors[:title]

    t.title = ""
    assert_predicate t, :invalid?

    t.title = nil
    assert_predicate t, :invalid?
  end

  def test_optionally_validates_length_of_using_is
    Topic.validates_length_of :title, is: 5, allow_nil: true

    t = Topic.new("title" => "valid", "content" => "whatever")
    assert_predicate t, :valid?

    t.title = nil
    assert_predicate t, :valid?
  end

  def test_validates_length_of_using_bignum
    bigmin = 2**30
    bigmax = 2**32
    bigrange = bigmin...bigmax
    assert_nothing_raised do
      Topic.validates_length_of :title, is: bigmin + 5
      Topic.validates_length_of :title, within: bigrange
      Topic.validates_length_of :title, in: bigrange
      Topic.validates_length_of :title, minimum: bigmin
      Topic.validates_length_of :title, maximum: bigmax
    end
  end

  def test_validates_length_of_nasty_params
    assert_raise(ArgumentError) { Topic.validates_length_of(:title, is: -6) }
    assert_raise(ArgumentError) { Topic.validates_length_of(:title, within: 6) }
    assert_raise(ArgumentError) { Topic.validates_length_of(:title, minimum: "a") }
    assert_raise(ArgumentError) { Topic.validates_length_of(:title, maximum: "a") }
    assert_raise(ArgumentError) { Topic.validates_length_of(:title, within: "a") }
    assert_raise(ArgumentError) { Topic.validates_length_of(:title, is: "a") }
  end

  def test_validates_length_of_custom_errors_for_minimum_with_message
    Topic.validates_length_of(:title, minimum: 5, message: "boo %{count}")
    t = Topic.new("title" => "uhoh", "content" => "whatever")
    assert_predicate t, :invalid?
    assert_predicate t.errors[:title], :any?
    assert_equal ["boo 5"], t.errors[:title]
  end

  def test_validates_length_of_custom_errors_for_minimum_with_too_short
    Topic.validates_length_of(:title, minimum: 5, too_short: "hoo %{count}")
    t = Topic.new("title" => "uhoh", "content" => "whatever")
    assert_predicate t, :invalid?
    assert_predicate t.errors[:title], :any?
    assert_equal ["hoo 5"], t.errors[:title]
  end

  def test_validates_length_of_custom_errors_for_maximum_with_message
    Topic.validates_length_of(:title, maximum: 5, message: "boo %{count}")
    t = Topic.new("title" => "uhohuhoh", "content" => "whatever")
    assert_predicate t, :invalid?
    assert_predicate t.errors[:title], :any?
    assert_equal ["boo 5"], t.errors[:title]
  end

  def test_validates_length_of_custom_errors_for_in
    Topic.validates_length_of(:title, in: 10..20, message: "hoo %{count}")
    t = Topic.new("title" => "uhohuhoh", "content" => "whatever")
    assert_predicate t, :invalid?
    assert_predicate t.errors[:title], :any?
    assert_equal ["hoo 10"], t.errors["title"]

    t = Topic.new("title" => "uhohuhohuhohuhohuhohuhohuhohuhoh", "content" => "whatever")
    assert_predicate t, :invalid?
    assert_predicate t.errors[:title], :any?
    assert_equal ["hoo 20"], t.errors["title"]
  end

  def test_validates_length_of_custom_errors_for_maximum_with_too_long
    Topic.validates_length_of(:title, maximum: 5, too_long: "hoo %{count}")
    t = Topic.new("title" => "uhohuhoh", "content" => "whatever")
    assert_predicate t, :invalid?
    assert_predicate t.errors[:title], :any?
    assert_equal ["hoo 5"], t.errors["title"]
  end

  def test_validates_length_of_custom_errors_for_both_too_short_and_too_long
    Topic.validates_length_of :title, minimum: 3, maximum: 5, too_short: "too short", too_long: "too long"

    t = Topic.new(title: "a")
    assert_predicate t, :invalid?
    assert_predicate t.errors[:title], :any?
    assert_equal ["too short"], t.errors["title"]

    t = Topic.new(title: "aaaaaa")
    assert_predicate t, :invalid?
    assert_predicate t.errors[:title], :any?
    assert_equal ["too long"], t.errors["title"]
  end

  def test_validates_length_of_custom_errors_for_is_with_message
    Topic.validates_length_of(:title, is: 5, message: "boo %{count}")
    t = Topic.new("title" => "uhohuhoh", "content" => "whatever")
    assert_predicate t, :invalid?
    assert_predicate t.errors[:title], :any?
    assert_equal ["boo 5"], t.errors["title"]
  end

  def test_validates_length_of_custom_errors_for_is_with_wrong_length
    Topic.validates_length_of(:title, is: 5, wrong_length: "hoo %{count}")
    t = Topic.new("title" => "uhohuhoh", "content" => "whatever")
    assert_predicate t, :invalid?
    assert_predicate t.errors[:title], :any?
    assert_equal ["hoo 5"], t.errors["title"]
  end

  def test_validates_length_of_using_minimum_utf8
    Topic.validates_length_of :title, minimum: 5

    t = Topic.new("title" => "一二三四五", "content" => "whatever")
    assert_predicate t, :valid?

    t.title = "一二三四"
    assert_predicate t, :invalid?
    assert_predicate t.errors[:title], :any?
    assert_equal ["is too short (minimum is 5 characters)"], t.errors["title"]
  end

  def test_validates_length_of_using_maximum_utf8
    Topic.validates_length_of :title, maximum: 5

    t = Topic.new("title" => "一二三四五", "content" => "whatever")
    assert_predicate t, :valid?

    t.title = "一二34五六"
    assert_predicate t, :invalid?
    assert_predicate t.errors[:title], :any?
    assert_equal ["is too long (maximum is 5 characters)"], t.errors["title"]
  end

  def test_validates_length_of_using_within_utf8
    Topic.validates_length_of(:title, :content, within: 3..5)

    t = Topic.new("title" => "一二", "content" => "12三四五六七")
    assert_predicate t, :invalid?
    assert_equal ["is too short (minimum is 3 characters)"], t.errors[:title]
    assert_equal ["is too long (maximum is 5 characters)"], t.errors[:content]
    t.title = "一二三"
    t.content = "12三"
    assert_predicate t, :valid?
  end

  def test_optionally_validates_length_of_using_within_utf8
    Topic.validates_length_of :title, within: 3..5, allow_nil: true

    t = Topic.new(title: "一二三四五")
    assert t.valid?, t.errors.inspect

    t = Topic.new(title: "一二三")
    assert t.valid?, t.errors.inspect

    t.title = nil
    assert t.valid?, t.errors.inspect
  end

  def test_validates_length_of_using_is_utf8
    Topic.validates_length_of :title, is: 5

    t = Topic.new("title" => "一二345", "content" => "whatever")
    assert_predicate t, :valid?

    t.title = "一二345六"
    assert_predicate t, :invalid?
    assert_predicate t.errors[:title], :any?
    assert_equal ["is the wrong length (should be 5 characters)"], t.errors["title"]
  end

  def test_validates_length_of_for_integer
    Topic.validates_length_of(:approved, is: 4)

    t = Topic.new("title" => "uhohuhoh", "content" => "whatever", approved: 1)
    assert_predicate t, :invalid?
    assert_predicate t.errors[:approved], :any?

    t = Topic.new("title" => "uhohuhoh", "content" => "whatever", approved: 1234)
    assert_predicate t, :valid?
  end

  def test_validates_length_of_for_ruby_class
    Person.validates_length_of :karma, minimum: 5

    p = Person.new
    p.karma = "Pix"
    assert_predicate p, :invalid?

    assert_equal ["is too short (minimum is 5 characters)"], p.errors[:karma]

    p.karma = "The Smiths"
    assert_predicate p, :valid?
  ensure
    Person.clear_validators!
  end

  def test_validates_length_of_for_infinite_maxima
    Topic.validates_length_of(:title, within: 5..Float::INFINITY)

    t = Topic.new("title" => "1234")
    assert_predicate t, :invalid?
    assert_predicate t.errors[:title], :any?

    t.title = "12345"
    assert_predicate t, :valid?

    Topic.validates_length_of(:author_name, maximum: Float::INFINITY)

    assert_predicate t, :valid?

    t.author_name = "A very long author name that should still be valid." * 100
    assert_predicate t, :valid?
  end

  def test_validates_length_of_using_maximum_should_not_allow_nil_when_nil_not_allowed
    Topic.validates_length_of :title, maximum: 10, allow_nil: false
    t = Topic.new
    assert_predicate t, :invalid?
  end

  def test_validates_length_of_using_maximum_should_not_allow_nil_and_empty_string_when_blank_not_allowed
    Topic.validates_length_of :title, maximum: 10, allow_blank: false
    t = Topic.new
    assert_predicate t, :invalid?

    t.title = ""
    assert_predicate t, :invalid?
  end

  def test_validates_length_of_using_both_minimum_and_maximum_should_not_allow_nil
    Topic.validates_length_of :title, minimum: 5, maximum: 10
    t = Topic.new
    assert_predicate t, :invalid?
  end

  def test_validates_length_of_using_minimum_0_should_not_allow_nil
    Topic.validates_length_of :title, minimum: 0
    t = Topic.new
    assert_predicate t, :invalid?

    t.title = ""
    assert_predicate t, :valid?
  end

  def test_validates_length_of_using_is_0_should_not_allow_nil
    Topic.validates_length_of :title, is: 0
    t = Topic.new
    assert_predicate t, :invalid?

    t.title = ""
    assert_predicate t, :valid?
  end

  def test_validates_with_diff_in_option
    Topic.validates_length_of(:title, is: 5)
    Topic.validates_length_of(:title, is: 5, if: Proc.new { false })

    assert_predicate Topic.new("title" => "david"), :valid?
    assert_predicate Topic.new("title" => "david2"), :invalid?
  end

  def test_validates_length_of_using_symbol_as_maximum
    Topic.validates_length_of :title, maximum: :five

    t = Topic.new("title" => "valid", "content" => "whatever")
    assert_predicate t, :valid?

    t.title = "notvalid"
    assert_predicate t, :invalid?
    assert_predicate t.errors[:title], :any?
    assert_equal ["is too long (maximum is 5 characters)"], t.errors[:title]

    t.title = ""
    assert_predicate t, :valid?
  end

  def test_validates_length_of_using_proc_as_maximum
    Topic.validates_length_of :title, maximum: ->(model) { 5 }

    t = Topic.new("title" => "valid", "content" => "whatever")
    assert_predicate t, :valid?

    t.title = "notvalid"
    assert_predicate t, :invalid?
    assert_predicate t.errors[:title], :any?
    assert_equal ["is too long (maximum is 5 characters)"], t.errors[:title]

    t.title = ""
    assert_predicate t, :valid?
  end

  def test_validates_length_of_using_proc_as_maximum_with_model_method
    Topic.define_method(:max_title_length) { 5 }
    Topic.validates_length_of :title, maximum: Proc.new(&:max_title_length)

    t = Topic.new("title" => "valid", "content" => "whatever")
    assert_predicate t, :valid?

    t.title = "notvalid"
    assert_predicate t, :invalid?
    assert_predicate t.errors[:title], :any?
    assert_equal ["is too long (maximum is 5 characters)"], t.errors[:title]

    t.title = ""
    assert_predicate t, :valid?
  end
end

lint.rb

# frozen_string_literal: true

module ActiveModel
  module Lint
    # == Active \Model \Lint \Tests
    #
    # You can test whether an object is compliant with the Active \Model API by
    # including <tt>ActiveModel::Lint::Tests</tt> in your TestCase. It will
    # include tests that tell you whether your object is fully compliant,
    # or if not, which aspects of the API are not implemented.
    #
    # Note an object is not required to implement all APIs in order to work
    # with Action Pack. This module only intends to provide guidance in case
    # you want all features out of the box.
    #
    # These tests do not attempt to determine the semantic correctness of the
    # returned values. For instance, you could implement <tt>valid?</tt> to
    # always return +true+, and the tests would pass. It is up to you to ensure
    # that the values are semantically meaningful.
    #
    # Objects you pass in are expected to return a compliant object from a call
    # to <tt>to_model</tt>. It is perfectly fine for <tt>to_model</tt> to return
    # +self+.
    module Tests
      # Passes if the object's model responds to <tt>to_key</tt> and if calling
      # this method returns +nil+ when the object is not persisted.
      # Fails otherwise.
      #
      # <tt>to_key</tt> returns an Enumerable of all (primary) key attributes
      # of the model, and is used to a generate unique DOM id for the object.
      def test_to_key
        assert_respond_to model, :to_key
        def model.persisted?() false end
        assert model.to_key.nil?, "to_key should return nil when `persisted?` returns false"
      end

      # Passes if the object's model responds to <tt>to_param</tt> and if
      # calling this method returns +nil+ when the object is not persisted.
      # Fails otherwise.
      #
      # <tt>to_param</tt> is used to represent the object's key in URLs.
      # Implementers can decide to either raise an exception or provide a
      # default in case the record uses a composite primary key. There are no
      # tests for this behavior in lint because it doesn't make sense to force
      # any of the possible implementation strategies on the implementer.
      def test_to_param
        assert_respond_to model, :to_param
        def model.to_key() [1] end
        def model.persisted?() false end
        assert model.to_param.nil?, "to_param should return nil when `persisted?` returns false"
      end

      # Passes if the object's model responds to <tt>to_partial_path</tt> and if
      # calling this method returns a string. Fails otherwise.
      #
      # <tt>to_partial_path</tt> is used for looking up partials. For example,
      # a BlogPost model might return "blog_posts/blog_post".
      def test_to_partial_path
        assert_respond_to model, :to_partial_path
        assert_kind_of String, model.to_partial_path
      end

      # Passes if the object's model responds to <tt>persisted?</tt> and if
      # calling this method returns either +true+ or +false+. Fails otherwise.
      #
      # <tt>persisted?</tt> is used when calculating the URL for an object.
      # If the object is not persisted, a form for that object, for instance,
      # will route to the create action. If it is persisted, a form for the
      # object will route to the update action.
      def test_persisted?
        assert_respond_to model, :persisted?
        assert_boolean model.persisted?, "persisted?"
      end

      # Passes if the object's model responds to <tt>model_name</tt> both as
      # an instance method and as a class method, and if calling this method
      # returns a string with some convenience methods: <tt>:human</tt>,
      # <tt>:singular</tt> and <tt>:plural</tt>.
      #
      # Check ActiveModel::Naming for more information.
      def test_model_naming
        assert_respond_to model.class, :model_name
        model_name = model.class.model_name
        assert_respond_to model_name, :to_str
        assert_respond_to model_name.human, :to_str
        assert_respond_to model_name.singular, :to_str
        assert_respond_to model_name.plural, :to_str

        assert_respond_to model, :model_name
        assert_equal model.model_name, model.class.model_name
      end

      # Passes if the object's model responds to <tt>errors</tt> and if calling
      # <tt>[](attribute)</tt> on the result of this method returns an array.
      # Fails otherwise.
      #
      # <tt>errors[attribute]</tt> is used to retrieve the errors of a model
      # for a given attribute. If errors are present, the method should return
      # an array of strings that are the errors for the attribute in question.
      # If localization is used, the strings should be localized for the current
      # locale. If no error is present, the method should return an empty array.
      def test_errors_aref
        assert_respond_to model, :errors
        assert_equal [], model.errors[:hello], "errors#[] should return an empty Array"
      end

      private
        def model
          assert_respond_to @model, :to_model
          @model.to_model
        end

        def assert_boolean(result, name)
          assert result == true || result == false, "#{name} should be a boolean"
        end
    end
  end
end

lint_test.rb

# frozen_string_literal: true

require "cases/helper"

class LintTest < ActiveModel::TestCase
  include ActiveModel::Lint::Tests

  class CompliantModel
    extend ActiveModel::Naming
    include ActiveModel::Conversion

    def persisted?() false end

    def errors
      Hash.new([])
    end
  end

  def setup
    @model = CompliantModel.new
  end
end

model.rb

# frozen_string_literal: true

module ActiveModel
  # == Active \Model \Basic \Model
  #
  # Allows implementing models similar to ActiveRecord::Base.
  # Includes ActiveModel::API for the required interface for an
  # object to interact with Action Pack and Action View, but can be
  # extended with other functionalities.
  #
  # A minimal implementation could be:
  #
  #   class Person
  #     include ActiveModel::Model
  #     attr_accessor :name, :age
  #   end
  #
  #   person = Person.new(name: 'bob', age: '18')
  #   person.name # => "bob"
  #   person.age  # => "18"
  #
  # If for some reason you need to run code on <tt>initialize</tt>, make
  # sure you call +super+ if you want the attributes hash initialization to
  # happen.
  #
  #   class Person
  #     include ActiveModel::Model
  #     attr_accessor :id, :name, :omg
  #
  #     def initialize(attributes={})
  #       super
  #       @omg ||= true
  #     end
  #   end
  #
  #   person = Person.new(id: 1, name: 'bob')
  #   person.omg # => true
  #
  # For more detailed information on other functionalities available, please
  # refer to the specific modules included in <tt>ActiveModel::Model</tt>
  # (see below).
  module Model
    extend ActiveSupport::Concern
    include ActiveModel::API
    include ActiveModel::Access

    ##
    # :method: slice
    #
    # :call-seq: slice(*methods)
    #
    # Returns a hash of the given methods with their names as keys and returned
    # values as values.
    #
    #--
    # Implemented by ActiveModel::Access#slice.

    ##
    # :method: values_at
    #
    # :call-seq: values_at(*methods)
    #
    # Returns an array of the values returned by the given methods.
    #
    #--
    # Implemented by ActiveModel::Access#values_at.
  end
end

model_test.rb

# frozen_string_literal: true

require "cases/helper"

class ModelTest < ActiveModel::TestCase
  include ActiveModel::Lint::Tests

  module DefaultValue
    def self.included(klass)
      klass.class_eval { attr_accessor :hello }
    end

    def initialize(*args)
      @attr ||= "default value"
      super
    end
  end

  class BasicModel
    include DefaultValue
    include ActiveModel::Model
    attr_accessor :attr
  end

  class BasicModelWithReversedMixins
    include ActiveModel::Model
    include DefaultValue
    attr_accessor :attr
  end

  class SimpleModel
    include ActiveModel::Model
    attr_accessor :attr
  end

  def setup
    @model = BasicModel.new
  end

  def test_initialize_with_params
    object = BasicModel.new(attr: "value")
    assert_equal "value", object.attr
  end

  def test_initialize_with_params_and_mixins_reversed
    object = BasicModelWithReversedMixins.new(attr: "value")
    assert_equal "value", object.attr
  end

  def test_initialize_with_nil_or_empty_hash_params_does_not_explode
    assert_nothing_raised do
      BasicModel.new()
      BasicModel.new(nil)
      BasicModel.new({})
      SimpleModel.new(attr: "value")
    end
  end

  def test_persisted_is_always_false
    object = BasicModel.new(attr: "value")
    assert_not object.persisted?
  end

  def test_mixin_inclusion_chain
    object = BasicModel.new
    assert_equal "default value", object.attr
  end

  def test_mixin_initializer_when_args_exist
    object = BasicModel.new(hello: "world")
    assert_equal "world", object.hello
  end

  def test_mixin_initializer_when_args_dont_exist
    assert_raises(ActiveModel::UnknownAttributeError) do
      SimpleModel.new(hello: "world")
    end
  end
end

mutable.rb

# frozen_string_literal: true

module ActiveModel
  module Type
    module Helpers # :nodoc: all
      module Mutable
        def cast(value)
          deserialize(serialize(value))
        end

        # +raw_old_value+ will be the `_before_type_cast` version of the
        # value (likely a string). +new_value+ will be the current, type
        # cast value.
        def changed_in_place?(raw_old_value, new_value)
          raw_old_value != serialize(new_value)
        end
      end
    end
  end
end

naming.rb

# frozen_string_literal: true

require "active_support/core_ext/hash/except"
require "active_support/core_ext/module/introspection"
require "active_support/core_ext/module/redefine_method"
require "active_support/core_ext/module/delegation"

module ActiveModel
  class Name
    include Comparable

    attr_accessor :singular, :plural, :element, :collection,
      :singular_route_key, :route_key, :param_key, :i18n_key,
      :name

    alias_method :cache_key, :collection

    ##
    # :method: ==
    #
    # :call-seq:
    #   ==(other)
    #
    # Equivalent to <tt>String#==</tt>. Returns +true+ if the class name and
    # +other+ are equal, otherwise +false+.
    #
    #   class BlogPost
    #     extend ActiveModel::Naming
    #   end
    #
    #   BlogPost.model_name == 'BlogPost'  # => true
    #   BlogPost.model_name == 'Blog Post' # => false

    ##
    # :method: ===
    #
    # :call-seq:
    #   ===(other)
    #
    # Equivalent to <tt>#==</tt>.
    #
    #   class BlogPost
    #     extend ActiveModel::Naming
    #   end
    #
    #   BlogPost.model_name === 'BlogPost'  # => true
    #   BlogPost.model_name === 'Blog Post' # => false

    ##
    # :method: <=>
    #
    # :call-seq:
    #   <=>(other)
    #
    # Equivalent to <tt>String#<=></tt>.
    #
    #   class BlogPost
    #     extend ActiveModel::Naming
    #   end
    #
    #   BlogPost.model_name <=> 'BlogPost'  # => 0
    #   BlogPost.model_name <=> 'Blog'      # => 1
    #   BlogPost.model_name <=> 'BlogPosts' # => -1

    ##
    # :method: =~
    #
    # :call-seq:
    #   =~(regexp)
    #
    # Equivalent to <tt>String#=~</tt>. Match the class name against the given
    # regexp. Returns the position where the match starts or +nil+ if there is
    # no match.
    #
    #   class BlogPost
    #     extend ActiveModel::Naming
    #   end
    #
    #   BlogPost.model_name =~ /Post/ # => 4
    #   BlogPost.model_name =~ /\d/   # => nil

    ##
    # :method: !~
    #
    # :call-seq:
    #   !~(regexp)
    #
    # Equivalent to <tt>String#!~</tt>. Match the class name against the given
    # regexp. Returns +true+ if there is no match, otherwise +false+.
    #
    #   class BlogPost
    #     extend ActiveModel::Naming
    #   end
    #
    #   BlogPost.model_name !~ /Post/ # => false
    #   BlogPost.model_name !~ /\d/   # => true

    ##
    # :method: eql?
    #
    # :call-seq:
    #   eql?(other)
    #
    # Equivalent to <tt>String#eql?</tt>. Returns +true+ if the class name and
    # +other+ have the same length and content, otherwise +false+.
    #
    #   class BlogPost
    #     extend ActiveModel::Naming
    #   end
    #
    #   BlogPost.model_name.eql?('BlogPost')  # => true
    #   BlogPost.model_name.eql?('Blog Post') # => false

    ##
    # :method: match?
    #
    # :call-seq:
    #   match?(regexp)
    #
    # Equivalent to <tt>String#match?</tt>. Match the class name against the
    # given regexp. Returns +true+ if there is a match, otherwise +false+.
    #
    #   class BlogPost
    #     extend ActiveModel::Naming
    #   end
    #
    #   BlogPost.model_name.match?(/Post/) # => true
    #   BlogPost.model_name.match?(/\d/) # => false

    ##
    # :method: to_s
    #
    # :call-seq:
    #   to_s()
    #
    # Returns the class name.
    #
    #   class BlogPost
    #     extend ActiveModel::Naming
    #   end
    #
    #   BlogPost.model_name.to_s # => "BlogPost"

    ##
    # :method: to_str
    #
    # :call-seq:
    #   to_str()
    #
    # Equivalent to +to_s+.
    delegate :==, :===, :<=>, :=~, :"!~", :eql?, :match?, :to_s,
             :to_str, :as_json, to: :name

    # Returns a new ActiveModel::Name instance. By default, the +namespace+
    # and +name+ option will take the namespace and name of the given class
    # respectively.
    # Use +locale+ argument for singularize and pluralize model name.
    #
    #   module Foo
    #     class Bar
    #     end
    #   end
    #
    #   ActiveModel::Name.new(Foo::Bar).to_s
    #   # => "Foo::Bar"
    def initialize(klass, namespace = nil, name = nil, locale = :en)
      @name = name || klass.name

      raise ArgumentError, "Class name cannot be blank. You need to supply a name argument when anonymous class given" if @name.blank?

      @unnamespaced = @name.delete_prefix("#{namespace.name}::") if namespace
      @klass        = klass
      @singular     = _singularize(@name)
      @plural       = ActiveSupport::Inflector.pluralize(@singular, locale)
      @uncountable  = @plural == @singular
      @element      = ActiveSupport::Inflector.underscore(ActiveSupport::Inflector.demodulize(@name))
      @human        = ActiveSupport::Inflector.humanize(@element)
      @collection   = ActiveSupport::Inflector.tableize(@name)
      @param_key    = (namespace ? _singularize(@unnamespaced) : @singular)
      @i18n_key     = @name.underscore.to_sym

      @route_key          = (namespace ? ActiveSupport::Inflector.pluralize(@param_key, locale) : @plural.dup)
      @singular_route_key = ActiveSupport::Inflector.singularize(@route_key, locale)
      @route_key << "_index" if @uncountable
    end

    # Transform the model name into a more human format, using I18n. By default,
    # it will underscore then humanize the class name.
    #
    #   class BlogPost
    #     extend ActiveModel::Naming
    #   end
    #
    #   BlogPost.model_name.human # => "Blog post"
    #
    # Specify +options+ with additional translating options.
    def human(options = {})
      return @human if i18n_keys.empty? || i18n_scope.empty?

      key, *defaults = i18n_keys
      defaults << options[:default] if options[:default]
      defaults << MISSING_TRANSLATION

      translation = I18n.translate(key, scope: i18n_scope, count: 1, **options, default: defaults)
      translation = @human if translation == MISSING_TRANSLATION
      translation
    end

    def uncountable?
      @uncountable
    end

    private
      MISSING_TRANSLATION = Object.new # :nodoc:

      def _singularize(string)
        ActiveSupport::Inflector.underscore(string).tr("/", "_")
      end

      def i18n_keys
        @i18n_keys ||= if @klass.respond_to?(:lookup_ancestors)
          @klass.lookup_ancestors.map { |klass| klass.model_name.i18n_key }
        else
          []
        end
      end

      def i18n_scope
        @i18n_scope ||= @klass.respond_to?(:i18n_scope) ? [@klass.i18n_scope, :models] : []
      end
  end

  # == Active \Model \Naming
  #
  # Creates a +model_name+ method on your object.
  #
  # To implement, just extend ActiveModel::Naming in your object:
  #
  #   class BookCover
  #     extend ActiveModel::Naming
  #   end
  #
  #   BookCover.model_name.name   # => "BookCover"
  #   BookCover.model_name.human  # => "Book cover"
  #
  #   BookCover.model_name.i18n_key              # => :book_cover
  #   BookModule::BookCover.model_name.i18n_key  # => :"book_module/book_cover"
  #
  # Providing the functionality that ActiveModel::Naming provides in your object
  # is required to pass the \Active \Model Lint test. So either extending the
  # provided method below, or rolling your own is required.
  module Naming
    def self.extended(base) # :nodoc:
      base.silence_redefinition_of_method :model_name
      base.delegate :model_name, to: :class
    end

    # Returns an ActiveModel::Name object for module. It can be
    # used to retrieve all kinds of naming-related information
    # (See ActiveModel::Name for more information).
    #
    #   class Person
    #     extend ActiveModel::Naming
    #   end
    #
    #   Person.model_name.name     # => "Person"
    #   Person.model_name.class    # => ActiveModel::Name
    #   Person.model_name.singular # => "person"
    #   Person.model_name.plural   # => "people"
    def model_name
      @_model_name ||= begin
        namespace = module_parents.detect do |n|
          n.respond_to?(:use_relative_model_naming?) && n.use_relative_model_naming?
        end
        ActiveModel::Name.new(self, namespace)
      end
    end

    # Returns the plural class name of a record or class.
    #
    #   ActiveModel::Naming.plural(post)             # => "posts"
    #   ActiveModel::Naming.plural(Highrise::Person) # => "highrise_people"
    def self.plural(record_or_class)
      model_name_from_record_or_class(record_or_class).plural
    end

    # Returns the singular class name of a record or class.
    #
    #   ActiveModel::Naming.singular(post)             # => "post"
    #   ActiveModel::Naming.singular(Highrise::Person) # => "highrise_person"
    def self.singular(record_or_class)
      model_name_from_record_or_class(record_or_class).singular
    end

    # Identifies whether the class name of a record or class is uncountable.
    #
    #   ActiveModel::Naming.uncountable?(Sheep) # => true
    #   ActiveModel::Naming.uncountable?(Post)  # => false
    def self.uncountable?(record_or_class)
      model_name_from_record_or_class(record_or_class).uncountable?
    end

    # Returns string to use while generating route names. It differs for
    # namespaced models regarding whether it's inside isolated engine.
    #
    #   # For isolated engine:
    #   ActiveModel::Naming.singular_route_key(Blog::Post) # => "post"
    #
    #   # For shared engine:
    #   ActiveModel::Naming.singular_route_key(Blog::Post) # => "blog_post"
    def self.singular_route_key(record_or_class)
      model_name_from_record_or_class(record_or_class).singular_route_key
    end

    # Returns string to use while generating route names. It differs for
    # namespaced models regarding whether it's inside isolated engine.
    #
    #   # For isolated engine:
    #   ActiveModel::Naming.route_key(Blog::Post) # => "posts"
    #
    #   # For shared engine:
    #   ActiveModel::Naming.route_key(Blog::Post) # => "blog_posts"
    #
    # The route key also considers if the noun is uncountable and, in
    # such cases, automatically appends _index.
    def self.route_key(record_or_class)
      model_name_from_record_or_class(record_or_class).route_key
    end

    # Returns string to use for params names. It differs for
    # namespaced models regarding whether it's inside isolated engine.
    #
    #   # For isolated engine:
    #   ActiveModel::Naming.param_key(Blog::Post) # => "post"
    #
    #   # For shared engine:
    #   ActiveModel::Naming.param_key(Blog::Post) # => "blog_post"
    def self.param_key(record_or_class)
      model_name_from_record_or_class(record_or_class).param_key
    end

    def self.model_name_from_record_or_class(record_or_class) # :nodoc:
      if record_or_class.respond_to?(:to_model)
        record_or_class.to_model.model_name
      else
        record_or_class.model_name
      end
    end
    private_class_method :model_name_from_record_or_class
  end
end

naming_test.rb

# frozen_string_literal: true

require "cases/helper"
require "models/contact"
require "models/sheep"
require "models/track_back"
require "models/blog_post"

class NamingTest < ActiveModel::TestCase
  def setup
    @model_name = ActiveModel::Name.new(Post::TrackBack)
  end

  def test_singular
    assert_equal "post_track_back", @model_name.singular
  end

  def test_plural
    assert_equal "post_track_backs", @model_name.plural
  end

  def test_element
    assert_equal "track_back", @model_name.element
  end

  def test_collection
    assert_equal "post/track_backs", @model_name.collection
  end

  def test_human
    assert_equal "Track back", @model_name.human
  end

  def test_route_key
    assert_equal "post_track_backs", @model_name.route_key
  end

  def test_param_key
    assert_equal "post_track_back", @model_name.param_key
  end

  def test_i18n_key
    assert_equal :"post/track_back", @model_name.i18n_key
  end

  def test_uncountable
    assert_equal false, @model_name.uncountable?
  end
end

class NamingWithNamespacedModelInIsolatedNamespaceTest < ActiveModel::TestCase
  def setup
    @model_name = ActiveModel::Name.new(Blog::Post, Blog)
  end

  def test_singular
    assert_equal "blog_post", @model_name.singular
  end

  def test_plural
    assert_equal "blog_posts", @model_name.plural
  end

  def test_element
    assert_equal "post", @model_name.element
  end

  def test_collection
    assert_equal "blog/posts", @model_name.collection
  end

  def test_human
    assert_equal "Post", @model_name.human
  end

  def test_route_key
    assert_equal "posts", @model_name.route_key
  end

  def test_param_key
    assert_equal "post", @model_name.param_key
  end

  def test_i18n_key
    assert_equal :"blog/post", @model_name.i18n_key
  end
end

class NamingWithNamespacedModelInSharedNamespaceTest < ActiveModel::TestCase
  def setup
    @model_name = ActiveModel::Name.new(Blog::Post)
  end

  def test_singular
    assert_equal "blog_post", @model_name.singular
  end

  def test_plural
    assert_equal "blog_posts", @model_name.plural
  end

  def test_element
    assert_equal "post", @model_name.element
  end

  def test_collection
    assert_equal "blog/posts", @model_name.collection
  end

  def test_human
    assert_equal "Post", @model_name.human
  end

  def test_route_key
    assert_equal "blog_posts", @model_name.route_key
  end

  def test_param_key
    assert_equal "blog_post", @model_name.param_key
  end

  def test_i18n_key
    assert_equal :"blog/post", @model_name.i18n_key
  end
end

class NamingWithSuppliedModelNameTest < ActiveModel::TestCase
  def setup
    @model_name = ActiveModel::Name.new(Blog::Post, nil, "Article")
  end

  def test_singular
    assert_equal "article", @model_name.singular
  end

  def test_plural
    assert_equal "articles", @model_name.plural
  end

  def test_element
    assert_equal "article", @model_name.element
  end

  def test_collection
    assert_equal "articles", @model_name.collection
  end

  def test_human
    assert_equal "Article", @model_name.human
  end

  def test_route_key
    assert_equal "articles", @model_name.route_key
  end

  def test_param_key
    assert_equal "article", @model_name.param_key
  end

  def test_i18n_key
    assert_equal :"article", @model_name.i18n_key
  end
end

class NamingWithSuppliedLocaleTest < ActiveModel::TestCase
  def setup
    ActiveSupport::Inflector.inflections(:cs) do |inflect|
      inflect.plural(/(e)l$/i, '\1lé')
    end

    @model_name = ActiveModel::Name.new(Blog::Post, nil, "Uzivatel", :cs)
  end

  def test_singular
    assert_equal "uzivatel", @model_name.singular
  end

  def test_plural
    assert_equal "uzivatelé", @model_name.plural
  end
end

class NamingUsingRelativeModelNameTest < ActiveModel::TestCase
  def setup
    @model_name = Blog::Post.model_name
  end

  def test_singular
    assert_equal "blog_post", @model_name.singular
  end

  def test_plural
    assert_equal "blog_posts", @model_name.plural
  end

  def test_element
    assert_equal "post", @model_name.element
  end

  def test_collection
    assert_equal "blog/posts", @model_name.collection
  end

  def test_human
    assert_equal "Post", @model_name.human
  end

  def test_route_key
    assert_equal "posts", @model_name.route_key
  end

  def test_param_key
    assert_equal "post", @model_name.param_key
  end

  def test_i18n_key
    assert_equal :"blog/post", @model_name.i18n_key
  end
end

class NamingHelpersTest < ActiveModel::TestCase
  def setup
    @klass  = Contact
    @record = @klass.new
    @singular = "contact"
    @plural = "contacts"
    @uncountable = Sheep
    @singular_route_key = "contact"
    @route_key = "contacts"
    @param_key = "contact"
  end

  def test_to_model_called_on_record
    assert_equal "post_named_track_backs", plural(Post::TrackBack.new)
  end

  def test_singular
    assert_equal @singular, singular(@record)
  end

  def test_singular_for_class
    assert_equal @singular, singular(@klass)
  end

  def test_plural
    assert_equal @plural, plural(@record)
  end

  def test_plural_for_class
    assert_equal @plural, plural(@klass)
  end

  def test_route_key
    assert_equal @route_key, route_key(@record)
    assert_equal @singular_route_key, singular_route_key(@record)
  end

  def test_route_key_for_class
    assert_equal @route_key, route_key(@klass)
    assert_equal @singular_route_key, singular_route_key(@klass)
  end

  def test_param_key
    assert_equal @param_key, param_key(@record)
  end

  def test_param_key_for_class
    assert_equal @param_key, param_key(@klass)
  end

  def test_uncountable
    assert uncountable?(@uncountable), "Expected 'sheep' to be uncountable"
    assert_not uncountable?(@klass), "Expected 'contact' to be countable"
  end

  def test_uncountable_route_key
    assert_equal "sheep", singular_route_key(@uncountable)
    assert_equal "sheep_index", route_key(@uncountable)
  end

  private
    def method_missing(method, *args)
      ActiveModel::Naming.public_send(method, *args)
    end
end

class NameWithAnonymousClassTest < ActiveModel::TestCase
  def test_anonymous_class_without_name_argument
    assert_raises(ArgumentError) do
      ActiveModel::Name.new(Class.new)
    end
  end

  def test_anonymous_class_with_name_argument
    model_name = ActiveModel::Name.new(Class.new, nil, "Anonymous")
    assert_equal "Anonymous", model_name
  end
end

class NamingMethodDelegationTest < ActiveModel::TestCase
  def test_model_name
    assert_equal Blog::Post.model_name, Blog::Post.new.model_name
  end
end

class OverridingAccessorsTest < ActiveModel::TestCase
  def test_overriding_accessors_keys
    model_name = ActiveModel::Name.new(Post::TrackBack).tap do |name|
      name.singular = :singular
      name.plural = :plural
      name.element = :element
      name.collection = :collection
      name.singular_route_key = :singular_route_key
      name.route_key = :route_key
      name.param_key = :param_key
      name.i18n_key = :i18n_key
      name.name = :name
    end

    assert_equal :singular, model_name.singular
    assert_equal :plural, model_name.plural
    assert_equal :element, model_name.element
    assert_equal :collection, model_name.collection
    assert_equal :singular_route_key, model_name.singular_route_key
    assert_equal :route_key, model_name.route_key
    assert_equal :param_key, model_name.param_key
    assert_equal :i18n_key, model_name.i18n_key
    assert_equal :name, model_name.name
  end
end

nested_error.rb

# frozen_string_literal: true

require "active_model/error"
require "forwardable"

module ActiveModel
  class NestedError < Error
    def initialize(base, inner_error, override_options = {})
      @base = base
      @inner_error = inner_error
      @attribute = override_options.fetch(:attribute) { inner_error.attribute }
      @type = override_options.fetch(:type) { inner_error.type }
      @raw_type = inner_error.raw_type
      @options = inner_error.options
    end

    attr_reader :inner_error

    extend Forwardable
    def_delegators :@inner_error, :message
  end
end

nested_error_test.rb

# frozen_string_literal: true

require "cases/helper"
require "active_model/nested_error"
require "models/topic"
require "models/reply"

class NestedErrorTest < ActiveModel::TestCase
  def test_initialize
    topic = Topic.new
    inner_error = ActiveModel::Error.new(topic, :title, :not_enough, count: 2)
    reply = Reply.new
    error = ActiveModel::NestedError.new(reply, inner_error)

    assert_equal reply, error.base
    assert_equal inner_error.attribute, error.attribute
    assert_equal inner_error.type, error.type
    assert_equal(inner_error.options, error.options)
  end

  test "initialize with overriding attribute and type" do
    topic = Topic.new
    inner_error = ActiveModel::Error.new(topic, :title, :not_enough, count: 2)
    reply = Reply.new
    error = ActiveModel::NestedError.new(reply, inner_error, attribute: :parent, type: :foo)

    assert_equal reply, error.base
    assert_equal :parent, error.attribute
    assert_equal :foo, error.type
    assert_equal(inner_error.options, error.options)
  end

  def test_message
    topic = Topic.new(author_name: "Bruce")
    inner_error = ActiveModel::Error.new(topic, :title, :not_enough, message: Proc.new { |model, options|
      "not good enough for #{model.author_name}"
    })
    reply = Reply.new(author_name: "Mark")
    error = ActiveModel::NestedError.new(reply, inner_error)

    assert_equal "not good enough for Bruce", error.message
  end

  def test_full_message
    topic = Topic.new(author_name: "Bruce")
    inner_error = ActiveModel::Error.new(topic, :title, :not_enough, message: Proc.new { |model, options|
      "not good enough for #{model.author_name}"
    })
    reply = Reply.new(author_name: "Mark")
    error = ActiveModel::NestedError.new(reply, inner_error)

    assert_equal "Title not good enough for Bruce", error.full_message
  end
end

numeric.rb

# frozen_string_literal: true

module ActiveModel
  module Type
    module Helpers # :nodoc: all
      module Numeric
        def serialize(value)
          cast(value)
        end

        def cast(value)
          # Checks whether the value is numeric. Spaceship operator
          # will return nil if value is not numeric.
          value = if value <=> 0
            value
          else
            case value
            when true then 1
            when false then 0
            else value.presence
            end
          end

          super(value)
        end

        def changed?(old_value, _new_value, new_value_before_type_cast) # :nodoc:
          (super || number_to_non_number?(old_value, new_value_before_type_cast)) &&
            !equal_nan?(old_value, new_value_before_type_cast)
        end

        private
          def equal_nan?(old_value, new_value)
            (old_value.is_a?(::Float) || old_value.is_a?(BigDecimal)) &&
              old_value.nan? &&
              old_value.instance_of?(new_value.class) &&
              new_value.nan?
          end

          def number_to_non_number?(old_value, new_value_before_type_cast)
            old_value != nil && non_numeric_string?(new_value_before_type_cast.to_s)
          end

          def non_numeric_string?(value)
            # 'wibble'.to_i will give zero, we want to make sure
            # that we aren't marking int zero to string zero as
            # changed.
            !NUMERIC_REGEX.match?(value)
          end

          NUMERIC_REGEX = /\A\s*[+-]?\d/
          private_constant :NUMERIC_REGEX
      end
    end
  end
end

numericality.rb

# frozen_string_literal: true

require "active_model/validations/comparability"
require "bigdecimal/util"

module ActiveModel
  module Validations
    class NumericalityValidator < EachValidator # :nodoc:
      include Comparability

      RANGE_CHECKS = { in: :in? }
      NUMBER_CHECKS = { odd: :odd?, even: :even? }

      RESERVED_OPTIONS = COMPARE_CHECKS.keys + NUMBER_CHECKS.keys + RANGE_CHECKS.keys + [:only_integer, :only_numeric]

      INTEGER_REGEX = /\A[+-]?\d+\z/

      HEXADECIMAL_REGEX = /\A[+-]?0[xX]/

      def check_validity!
        options.slice(*COMPARE_CHECKS.keys).each do |option, value|
          unless value.is_a?(Numeric) || value.is_a?(Proc) || value.is_a?(Symbol)
            raise ArgumentError, ":#{option} must be a number, a symbol or a proc"
          end
        end

        options.slice(*RANGE_CHECKS.keys).each do |option, value|
          unless value.is_a?(Range)
            raise ArgumentError, ":#{option} must be a range"
          end
        end
      end

      def validate_each(record, attr_name, value, precision: Float::DIG, scale: nil)
        unless is_number?(value, precision, scale)
          record.errors.add(attr_name, :not_a_number, **filtered_options(value))
          return
        end

        if allow_only_integer?(record) && !is_integer?(value)
          record.errors.add(attr_name, :not_an_integer, **filtered_options(value))
          return
        end

        value = parse_as_number(value, precision, scale)

        options.slice(*RESERVED_OPTIONS).each do |option, option_value|
          if NUMBER_CHECKS.include?(option)
            unless value.to_i.public_send(NUMBER_CHECKS[option])
              record.errors.add(attr_name, option, **filtered_options(value))
            end
          elsif RANGE_CHECKS.include?(option)
            unless value.public_send(RANGE_CHECKS[option], option_value)
              record.errors.add(attr_name, option, **filtered_options(value).merge!(count: option_value))
            end
          elsif COMPARE_CHECKS.include?(option)
            option_value = option_as_number(record, option_value, precision, scale)
            unless value.public_send(COMPARE_CHECKS[option], option_value)
              record.errors.add(attr_name, option, **filtered_options(value).merge!(count: option_value))
            end
          end
        end
      end

    private
      def option_as_number(record, option_value, precision, scale)
        parse_as_number(option_value(record, option_value), precision, scale)
      end

      def parse_as_number(raw_value, precision, scale)
        if raw_value.is_a?(Float)
          parse_float(raw_value, precision, scale)
        elsif raw_value.is_a?(BigDecimal)
          round(raw_value, scale)
        elsif raw_value.is_a?(Numeric)
          raw_value
        elsif is_integer?(raw_value)
          raw_value.to_i
        elsif !is_hexadecimal_literal?(raw_value)
          parse_float(Kernel.Float(raw_value), precision, scale)
        end
      end

      def parse_float(raw_value, precision, scale)
        round(raw_value, scale).to_d(precision)
      end

      def round(raw_value, scale)
        scale ? raw_value.round(scale) : raw_value
      end

      def is_number?(raw_value, precision, scale)
        if options[:only_numeric] && !raw_value.is_a?(Numeric)
          return false
        end

        !parse_as_number(raw_value, precision, scale).nil?
      rescue ArgumentError, TypeError
        false
      end

      def is_integer?(raw_value)
        INTEGER_REGEX.match?(raw_value.to_s)
      end

      def is_hexadecimal_literal?(raw_value)
        HEXADECIMAL_REGEX.match?(raw_value.to_s)
      end

      def filtered_options(value)
        filtered = options.except(*RESERVED_OPTIONS)
        filtered[:value] = value
        filtered
      end

      def allow_only_integer?(record)
        case options[:only_integer]
        when Symbol
          record.send(options[:only_integer])
        when Proc
          options[:only_integer].call(record)
        else
          options[:only_integer]
        end
      end

      def prepare_value_for_validation(value, record, attr_name)
        return value if record_attribute_changed_in_place?(record, attr_name)

        came_from_user = :"#{attr_name}_came_from_user?"

        if record.respond_to?(came_from_user)
          if record.public_send(came_from_user)
            raw_value = record.public_send(:"#{attr_name}_before_type_cast")
          elsif record.respond_to?(:read_attribute)
            raw_value = record.read_attribute(attr_name)
          end
        else
          before_type_cast = :"#{attr_name}_before_type_cast"
          if record.respond_to?(before_type_cast)
            raw_value = record.public_send(before_type_cast)
          end
        end

        raw_value || value
      end

      def record_attribute_changed_in_place?(record, attr_name)
        record.respond_to?(:attribute_changed_in_place?) &&
          record.attribute_changed_in_place?(attr_name.to_s)
      end
    end

    module HelperMethods
      # Validates whether the value of the specified attribute is numeric by
      # trying to convert it to a float with Kernel.Float (if <tt>only_integer</tt>
      # is +false+) or applying it to the regular expression <tt>/\A[\+\-]?\d+\z/</tt>
      # (if <tt>only_integer</tt> is set to +true+). Precision of Kernel.Float values
      # are guaranteed up to 15 digits.
      #
      #   class Person < ActiveRecord::Base
      #     validates_numericality_of :value, on: :create
      #   end
      #
      # Configuration options:
      # * <tt>:message</tt> - A custom error message (default is: "is not a number").
      # * <tt>:only_integer</tt> - Specifies whether the value has to be an
      #   integer (default is +false+).
      # * <tt>:only_numeric</tt> - Specifies whether the value has to be an
      #   instance of Numeric (default is +false+). The default behavior is to
      #   attempt parsing the value if it is a String.
      # * <tt>:allow_nil</tt> - Skip validation if attribute is +nil+ (default is
      #   +false+). Notice that for Integer and Float columns empty strings are
      #   converted to +nil+.
      # * <tt>:greater_than</tt> - Specifies the value must be greater than the
      #   supplied value.
      # * <tt>:greater_than_or_equal_to</tt> - Specifies the value must be
      #   greater than or equal the supplied value.
      # * <tt>:equal_to</tt> - Specifies the value must be equal to the supplied
      #   value.
      # * <tt>:less_than</tt> - Specifies the value must be less than the
      #   supplied value.
      # * <tt>:less_than_or_equal_to</tt> - Specifies the value must be less
      #   than or equal the supplied value.
      # * <tt>:other_than</tt> - Specifies the value must be other than the
      #   supplied value.
      # * <tt>:odd</tt> - Specifies the value must be an odd number.
      # * <tt>:even</tt> - Specifies the value must be an even number.
      # * <tt>:in</tt> - Check that the value is within a range.
      #
      # There is also a list of default options supported by every validator:
      # +:if+, +:unless+, +:on+, +:allow_nil+, +:allow_blank+, and +:strict+ .
      # See ActiveModel::Validations::ClassMethods#validates for more information.
      #
      # The following checks can also be supplied with a proc or a symbol which
      # corresponds to a method:
      #
      # * <tt>:greater_than</tt>
      # * <tt>:greater_than_or_equal_to</tt>
      # * <tt>:equal_to</tt>
      # * <tt>:less_than</tt>
      # * <tt>:less_than_or_equal_to</tt>
      # * <tt>:only_integer</tt>
      # * <tt>:other_than</tt>
      #
      # For example:
      #
      #   class Person < ActiveRecord::Base
      #     validates_numericality_of :width, less_than: ->(person) { person.height }
      #     validates_numericality_of :width, greater_than: :minimum_weight
      #   end
      def validates_numericality_of(*attr_names)
        validates_with NumericalityValidator, _merge_attributes(attr_names)
      end
    end
  end
end

numericality_validation_test.rb

# frozen_string_literal: true

require "cases/helper"

require "models/topic"
require "models/person"

require "bigdecimal"
require "active_support/core_ext/big_decimal"
require "active_support/core_ext/object/inclusion"

class NumericalityValidationTest < ActiveModel::TestCase
  def teardown
    Topic.clear_validators!
  end

  NIL = [nil]
  BLANK = ["", " ", " \t \r \n"]
  BIGDECIMAL_STRINGS = %w(12345678901234567890.1234567890) # 30 significant digits
  FLOAT_STRINGS = %w(0.0 +0.0 -0.0 10.0 10.5 -10.5 -0.0001 -090.1 90.1e1 -90.1e5 -90.1e-5 90e-5)
  INTEGER_STRINGS = %w(0 +0 -0 10 +10 -10 0090 -090)
  NUMERIC_FLOATS = [0.0, 10.0, 10.5, -10.5, -0.0001]
  NUMERIC_INTEGERS = [0, 10, -10]
  FLOATS = NUMERIC_FLOATS + FLOAT_STRINGS
  INTEGERS = NUMERIC_INTEGERS + INTEGER_STRINGS
  BIGDECIMAL = BIGDECIMAL_STRINGS.collect! { |bd| BigDecimal(bd) }
  JUNK = ["not a number", "42 not a number", "0xdeadbeef", "-0xdeadbeef", "+0xdeadbeef", "0xinvalidhex", "0Xdeadbeef", "00-1", "--3", "+-3", "+3-1", "-+019.0", "12.12.13.12", "123\nnot a number"]
  INFINITY = [1.0 / 0.0]

  def test_default_validates_numericality_of
    Topic.validates_numericality_of :approved
    assert_invalid_values(NIL + BLANK + JUNK)
    assert_valid_values(FLOATS + INTEGERS + BIGDECIMAL + INFINITY)
  end

  def test_validates_numericality_of_with_nil_allowed
    Topic.validates_numericality_of :approved, allow_nil: true

    assert_invalid_values(JUNK + BLANK)
    assert_valid_values(NIL + FLOATS + INTEGERS + BIGDECIMAL + INFINITY)
  end

  def test_validates_numericality_of_with_blank_allowed
    Topic.validates_numericality_of :approved, allow_blank: true

    assert_invalid_values(JUNK)
    assert_valid_values(NIL + BLANK + FLOATS + INTEGERS + BIGDECIMAL + INFINITY)
  end

  def test_validates_numericality_of_with_integer_only
    Topic.validates_numericality_of :approved, only_integer: true

    assert_invalid_values(NIL + BLANK + JUNK + FLOATS + BIGDECIMAL + INFINITY)
    assert_valid_values(INTEGERS)
  end

  def test_validates_numericality_of_with_integer_only_and_nil_allowed
    Topic.validates_numericality_of :approved, only_integer: true, allow_nil: true

    assert_invalid_values(JUNK + BLANK + FLOATS + BIGDECIMAL + INFINITY)
    assert_valid_values(NIL + INTEGERS)
  end

  def test_validates_numericality_of_with_integer_only_and_symbol_as_value
    Topic.validates_numericality_of :approved, only_integer: :condition_is_false

    assert_invalid_values(NIL + BLANK + JUNK)
    assert_valid_values(FLOATS + INTEGERS + BIGDECIMAL + INFINITY)
  end

  def test_validates_numericality_of_with_integer_only_and_proc_as_value
    Topic.define_method(:allow_only_integers?) { false }
    Topic.validates_numericality_of :approved, only_integer: Proc.new(&:allow_only_integers?)

    assert_invalid_values(NIL + BLANK + JUNK)
    assert_valid_values(FLOATS + INTEGERS + BIGDECIMAL + INFINITY)
  end

  def test_validates_numericality_of_with_numeric_only
    Topic.validates_numericality_of :approved, only_numeric: true

    assert_invalid_values(NIL + BLANK + JUNK + FLOAT_STRINGS + INTEGER_STRINGS)
    assert_valid_values(NUMERIC_FLOATS + NUMERIC_INTEGERS + BIGDECIMAL + INFINITY)
  end

  def test_validates_numericality_of_with_numeric_only_and_nil_allowed
    Topic.validates_numericality_of :approved, only_numeric: true, allow_nil: true

    assert_invalid_values(JUNK + BLANK + FLOAT_STRINGS + INTEGER_STRINGS)
    assert_valid_values(NIL + NUMERIC_FLOATS + NUMERIC_INTEGERS + BIGDECIMAL + INFINITY)
  end

  def test_validates_numericality_with_greater_than
    Topic.validates_numericality_of :approved, greater_than: 10

    assert_invalid_values([-10, 10], "must be greater than 10")
    assert_valid_values([11])
  end

  def test_validates_numericality_with_greater_than_using_differing_numeric_types
    Topic.validates_numericality_of :approved, greater_than: BigDecimal("97.18")

    assert_invalid_values([-97.18, BigDecimal("97.18"), BigDecimal("-97.18")], "must be greater than 97.18")
    assert_valid_values([97.19, 98, BigDecimal("98"), BigDecimal("97.19")])
  end

  def test_validates_numericality_with_greater_than_using_string_value
    Topic.validates_numericality_of :approved, greater_than: 10

    assert_invalid_values(["-10", "9", "9.9", "10"], "must be greater than 10")
    assert_valid_values(["10.1", "11"])
  end

  def test_validates_numericality_with_greater_than_or_equal
    Topic.validates_numericality_of :approved, greater_than_or_equal_to: 10

    assert_invalid_values([-9, 9], "must be greater than or equal to 10")
    assert_valid_values([10])
  end

  def test_validates_numericality_with_greater_than_or_equal_using_differing_numeric_types
    Topic.validates_numericality_of :approved, greater_than_or_equal_to: BigDecimal("97.18")

    assert_invalid_values([-97.18, 97.17, 97, BigDecimal("97.17"), BigDecimal("-97.18")], "must be greater than or equal to 97.18")
    assert_valid_values([97.18, 98, BigDecimal("97.19")])
  end

  def test_validates_numericality_with_greater_than_or_equal_using_string_value
    Topic.validates_numericality_of :approved, greater_than_or_equal_to: 10

    assert_invalid_values(["-10", "9", "9.9"], "must be greater than or equal to 10")
    assert_valid_values(["10", "10.1", "11"])
  end

  def test_validates_numericality_with_equal_to
    Topic.validates_numericality_of :approved, equal_to: 10

    assert_invalid_values([-10, 11] + INFINITY, "must be equal to 10")
    assert_valid_values([10])
  end

  def test_validates_numericality_with_equal_to_using_differing_numeric_types
    Topic.validates_numericality_of :approved, equal_to: BigDecimal("97.18")

    assert_invalid_values([-97.18], "must be equal to 97.18")
    assert_valid_values([BigDecimal("97.18")])
  end

  def test_validates_numericality_with_equal_to_using_string_value
    Topic.validates_numericality_of :approved, equal_to: 10

    assert_invalid_values(["-10", "9", "9.9", "10.1", "11"], "must be equal to 10")
    assert_valid_values(["10"])
  end

  def test_validates_numericality_with_less_than
    Topic.validates_numericality_of :approved, less_than: 10

    assert_invalid_values([10], "must be less than 10")
    assert_valid_values([-9, 9])
  end

  def test_validates_numericality_with_less_than_using_differing_numeric_types
    Topic.validates_numericality_of :approved, less_than: BigDecimal("97.18")

    assert_invalid_values([97.18, BigDecimal("97.18")], "must be less than 97.18")
    assert_valid_values([-97.0, 97.0, -97, 97, BigDecimal("-97"), BigDecimal("97")])
  end

  def test_validates_numericality_with_less_than_using_string_value
    Topic.validates_numericality_of :approved, less_than: 10

    assert_invalid_values(["10", "10.1", "11"], "must be less than 10")
    assert_valid_values(["-10", "9", "9.9"])
  end

  def test_validates_numericality_with_less_than_or_equal_to
    Topic.validates_numericality_of :approved, less_than_or_equal_to: 10

    assert_invalid_values([11], "must be less than or equal to 10")
    assert_valid_values([-10, 10])
  end

  def test_validates_numericality_with_less_than_or_equal_to_using_differing_numeric_types
    Topic.validates_numericality_of :approved, less_than_or_equal_to: BigDecimal("97.18")

    assert_invalid_values([97.19, 98], "must be less than or equal to 97.18")
    assert_valid_values([-97.18, BigDecimal("-97.18"), BigDecimal("97.18")])
  end

  def test_validates_numericality_with_less_than_or_equal_using_string_value
    Topic.validates_numericality_of :approved, less_than_or_equal_to: 10

    assert_invalid_values(["10.1", "11"], "must be less than or equal to 10")
    assert_valid_values(["-10", "9", "9.9", "10"])
  end

  def test_validates_numericality_with_odd
    Topic.validates_numericality_of :approved, odd: true

    assert_invalid_values([-2, 2], "must be odd")
    assert_valid_values([-1, 1])
  end

  def test_validates_numericality_with_even
    Topic.validates_numericality_of :approved, even: true

    assert_invalid_values([-1, 1], "must be even")
    assert_valid_values([-2, 2])
  end

  def test_validates_numericality_with_greater_than_less_than_and_even
    Topic.validates_numericality_of :approved, greater_than: 1, less_than: 4, even: true

    assert_invalid_values([1, 3, 4])
    assert_valid_values([2])
  end

  def test_validates_numericality_with_other_than
    Topic.validates_numericality_of :approved, other_than: 0

    assert_invalid_values([0, 0.0])
    assert_valid_values([-1, 42])
  end

  def test_validates_numericality_with_in
    Topic.validates_numericality_of :approved, in: 1..3

    assert_invalid_values([0, 4])
    assert_valid_values([1, 2, 3])
  end

  def test_validates_numericality_with_other_than_using_string_value
    Topic.validates_numericality_of :approved, other_than: 0

    assert_invalid_values(["0", "0.0"])
    assert_valid_values(["-1", "1.1", "42"])
  end

  def test_validates_numericality_with_proc
    Topic.define_method(:min_approved) { 5 }
    Topic.validates_numericality_of :approved, greater_than_or_equal_to: Proc.new(&:min_approved)

    assert_invalid_values([3, 4], "must be greater than or equal to 5")
    assert_valid_values([5, 6])
  ensure
    Topic.remove_method :min_approved
  end

  def test_validates_numericality_with_symbol
    Topic.define_method(:max_approved) { 5 }
    Topic.validates_numericality_of :approved, less_than_or_equal_to: :max_approved

    assert_invalid_values([6], "must be less than or equal to 5")
    assert_valid_values([4, 5])
  ensure
    Topic.remove_method :max_approved
  end

  def test_validates_numericality_with_numeric_message
    Topic.validates_numericality_of :approved, less_than: 4, message: "smaller than %{count}"
    topic = Topic.new("title" => "numeric test", "approved" => 10)

    assert_not_predicate topic, :valid?
    assert_equal ["smaller than 4"], topic.errors[:approved]

    Topic.validates_numericality_of :approved, greater_than: 4, message: "greater than %{count}"
    topic = Topic.new("title" => "numeric test", "approved" => 1)

    assert_not_predicate topic, :valid?
    assert_equal ["greater than 4"], topic.errors[:approved]
  end

  def test_validates_numericality_of_for_ruby_class
    Person.validates_numericality_of :karma, allow_nil: false

    p = Person.new
    p.karma = "Pix"
    assert_predicate p, :invalid?

    assert_equal ["is not a number"], p.errors[:karma]

    p.karma = "1234"
    assert_predicate p, :valid?
  ensure
    Person.clear_validators!
  end

  def test_validates_numericality_using_value_before_type_cast_if_possible
    Topic.validates_numericality_of :price

    topic = Topic.new(price: 50)

    assert_equal "$50.00", topic.price
    assert_equal 50, topic.price_before_type_cast
    assert_predicate topic, :valid?
  end

  def test_validates_numericality_with_exponent_number
    base = 10_000_000_000_000_000
    Topic.validates_numericality_of :approved, less_than_or_equal_to: base
    topic = Topic.new
    topic.approved = (base + 1).to_s

    assert_predicate topic, :invalid?
  end

  def test_validates_numericality_with_object_acting_as_numeric
    klass = Class.new do
      def to_f
        123.54
      end
    end

    Topic.validates_numericality_of :price
    topic = Topic.new(price: klass.new)

    assert_predicate topic, :valid?
  end

  def test_validates_numericality_with_invalid_args
    assert_raise(ArgumentError) { Topic.validates_numericality_of :approved, greater_than_or_equal_to: "foo" }
    assert_raise(ArgumentError) { Topic.validates_numericality_of :approved, less_than_or_equal_to: "foo" }
    assert_raise(ArgumentError) { Topic.validates_numericality_of :approved, greater_than: "foo" }
    assert_raise(ArgumentError) { Topic.validates_numericality_of :approved, less_than: "foo" }
    assert_raise(ArgumentError) { Topic.validates_numericality_of :approved, equal_to: "foo" }
    assert_raise(ArgumentError) { Topic.validates_numericality_of :approved, in: "foo" }
  end

  def test_validates_numericality_equality_for_float_and_big_decimal
    Topic.validates_numericality_of :approved, equal_to: BigDecimal("65.6")

    assert_invalid_values([Float("65.5"), BigDecimal("65.7")], "must be equal to 65.6")
    assert_valid_values([Float("65.6"), BigDecimal("65.6")])
  end

  private
    def assert_invalid_values(values, error = nil)
      with_each_topic_approved_value(values) do |topic, value|
        assert topic.invalid?, "#{value.inspect} not rejected as a number"
        assert topic.errors[:approved].any?, "FAILED for #{value.inspect}"
        assert_equal error, topic.errors[:approved].first if error
      end
    end

    def assert_valid_values(values)
      with_each_topic_approved_value(values) do |topic, value|
        assert topic.valid?, "#{value.inspect} not accepted as a number with validation error: #{topic.errors[:approved].first}"
      end
    end

    def with_each_topic_approved_value(values)
      topic = Topic.new(title: "numeric test", content: "whatever")
      values.each do |value|
        topic.approved = value
        yield topic, value
      end
    end
end

person.rb

# frozen_string_literal: true

class Person
  include ActiveModel::Validations
  extend  ActiveModel::Translation

  attr_accessor :title, :karma, :salary, :gender

  def condition_is_true
    true
  end

  def condition_is_false
    false
  end
end

class Person::Gender
  extend ActiveModel::Translation
end

class Child < Person
end

person_with_validator.rb

# frozen_string_literal: true

class PersonWithValidator
  include ActiveModel::Validations

  class PresenceValidator < ActiveModel::EachValidator
    def validate_each(record, attribute, value)
      record.errors.add(attribute, message: "Local validator#{options[:custom]}") if value.blank?
    end
  end

  class LikeValidator < ActiveModel::EachValidator
    def initialize(options)
      @with = options[:with]
      super
    end

    def validate_each(record, attribute, value)
      unless value[@with]
        record.errors.add attribute, "does not appear to be like #{@with}"
      end
    end
  end

  attr_accessor :title, :karma
end

presence.rb

# frozen_string_literal: true

module ActiveModel
  module Validations
    class PresenceValidator < EachValidator # :nodoc:
      def validate_each(record, attr_name, value)
        record.errors.add(attr_name, :blank, **options) if value.blank?
      end
    end

    module HelperMethods
      # Validates that the specified attributes are not blank (as defined by
      # Object#blank?). Happens by default on save.
      #
      #   class Person < ActiveRecord::Base
      #     validates_presence_of :first_name
      #   end
      #
      # The first_name attribute must be in the object and it cannot be blank.
      #
      # If you want to validate the presence of a boolean field (where the real
      # values are +true+ and +false+), you will want to use
      # <tt>validates_inclusion_of :field_name, in: [true, false]</tt>.
      #
      # This is due to the way Object#blank? handles boolean values:
      # <tt>false.blank? # => true</tt>.
      #
      # Configuration options:
      # * <tt>:message</tt> - A custom error message (default is: "can't be blank").
      #
      # There is also a list of default options supported by every validator:
      # +:if+, +:unless+, +:on+, +:allow_nil+, +:allow_blank+, and +:strict+.
      # See ActiveModel::Validations::ClassMethods#validates for more information.
      def validates_presence_of(*attr_names)
        validates_with PresenceValidator, _merge_attributes(attr_names)
      end
    end
  end
end

presence_validation_test.rb

# frozen_string_literal: true

require "cases/helper"

require "models/topic"
require "models/person"
require "models/custom_reader"

class PresenceValidationTest < ActiveModel::TestCase
  teardown do
    Topic.clear_validators!
    Person.clear_validators!
    CustomReader.clear_validators!
  end

  def test_validate_presences
    Topic.validates_presence_of(:title, :content)

    t = Topic.new
    assert_predicate t, :invalid?
    assert_equal ["can't be blank"], t.errors[:title]
    assert_equal ["can't be blank"], t.errors[:content]

    t.title = "something"
    t.content = "   "

    assert_predicate t, :invalid?
    assert_equal ["can't be blank"], t.errors[:content]

    t.content = "like stuff"

    assert_predicate t, :valid?
  end

  def test_accepts_array_arguments
    Topic.validates_presence_of %w(title content)
    t = Topic.new
    assert_predicate t, :invalid?
    assert_equal ["can't be blank"], t.errors[:title]
    assert_equal ["can't be blank"], t.errors[:content]
  end

  def test_validates_acceptance_of_with_custom_error_using_quotes
    Person.validates_presence_of :karma, message: "This string contains 'single' and \"double\" quotes"
    p = Person.new
    assert_predicate p, :invalid?
    assert_equal "This string contains 'single' and \"double\" quotes", p.errors[:karma].last
  end

  def test_validates_presence_of_for_ruby_class
    Person.validates_presence_of :karma

    p = Person.new
    assert_predicate p, :invalid?

    assert_equal ["can't be blank"], p.errors[:karma]

    p.karma = "Cold"
    assert_predicate p, :valid?
  end

  def test_validates_presence_of_for_ruby_class_with_custom_reader
    CustomReader.validates_presence_of :karma

    p = CustomReader.new
    assert_predicate p, :invalid?

    assert_equal ["can't be blank"], p.errors[:karma]

    p[:karma] = "Cold"
    assert_predicate p, :valid?
  end

  def test_validates_presence_of_with_allow_nil_option
    Topic.validates_presence_of(:title, allow_nil: true)

    t = Topic.new(title: "something")
    assert t.valid?, t.errors.full_messages

    t.title = ""
    assert_predicate t, :invalid?
    assert_equal ["can't be blank"], t.errors[:title]

    t.title = "  "
    assert t.invalid?, t.errors.full_messages
    assert_equal ["can't be blank"], t.errors[:title]

    t.title = nil
    assert t.valid?, t.errors.full_messages
  end

  def test_validates_presence_of_with_allow_blank_option
    Topic.validates_presence_of(:title, allow_blank: true)

    t = Topic.new(title: "something")
    assert t.valid?, t.errors.full_messages

    t.title = ""
    assert t.valid?, t.errors.full_messages

    t.title = "  "
    assert t.valid?, t.errors.full_messages

    t.title = nil
    assert t.valid?, t.errors.full_messages
  end
end

railtie.rb

# frozen_string_literal: true

require "active_model"
require "rails"

module ActiveModel
  class Railtie < Rails::Railtie # :nodoc:
    config.eager_load_namespaces << ActiveModel

    config.active_model = ActiveSupport::OrderedOptions.new

    initializer "active_model.secure_password" do
      ActiveModel::SecurePassword.min_cost = Rails.env.test?
    end

    initializer "active_model.i18n_customize_full_message" do
      ActiveModel::Error.i18n_customize_full_message = config.active_model.delete(:i18n_customize_full_message) || false
    end
  end
end

railtie_test.rb

# frozen_string_literal: true

require "cases/helper"
require "active_support/testing/isolation"

class RailtieTest < ActiveModel::TestCase
  include ActiveSupport::Testing::Isolation

  def setup
    require "active_model/railtie"

    # Set a fake logger to avoid creating the log directory automatically
    fake_logger = Logger.new(nil)

    @app ||= Class.new(::Rails::Application) do
      config.eager_load = false
      config.logger = fake_logger
    end
  end

  test "secure password min_cost is false in the development environment" do
    Rails.env = "development"
    @app.initialize!

    assert_equal false, ActiveModel::SecurePassword.min_cost
  end

  test "secure password min_cost is true in the test environment" do
    Rails.env = "test"
    @app.initialize!

    assert_equal true, ActiveModel::SecurePassword.min_cost
  end

  test "i18n customize full message defaults to false" do
    @app.initialize!

    assert_equal false, ActiveModel::Error.i18n_customize_full_message
  end

  test "i18n customize full message can be disabled" do
    @app.config.active_model.i18n_customize_full_message = false
    @app.initialize!

    assert_equal false, ActiveModel::Error.i18n_customize_full_message
  end

  test "i18n customize full message can be enabled" do
    @app.config.active_model.i18n_customize_full_message = true
    @app.initialize!

    assert_equal true, ActiveModel::Error.i18n_customize_full_message
  end
end

registry.rb

# frozen_string_literal: true

module ActiveModel
  module Type
    class Registry # :nodoc:
      def initialize
        @registrations = {}
      end

      def initialize_copy(other)
        @registrations = @registrations.dup
        super
      end

      def register(type_name, klass = nil, &block)
        unless block_given?
          block = proc { |_, *args| klass.new(*args) }
          block.ruby2_keywords if block.respond_to?(:ruby2_keywords)
        end
        registrations[type_name] = block
      end

      def lookup(symbol, *args)
        registration = registrations[symbol]

        if registration
          registration.call(symbol, *args)
        else
          raise ArgumentError, "Unknown type #{symbol.inspect}"
        end
      end
      ruby2_keywords(:lookup)

      private
        attr_reader :registrations
    end
  end
end

registry_test.rb

# frozen_string_literal: true

require "cases/helper"

module ActiveModel
  module Type
    class RegistryTest < ActiveModel::TestCase
      test "a class can be registered for a symbol" do
        registry = Type::Registry.new
        registry.register(:foo, ::String)
        registry.register(:bar, ::Array)

        assert_equal "", registry.lookup(:foo)
        assert_equal [], registry.lookup(:bar)
        assert_equal [:a, :a], registry.lookup(:bar, 2, :a) # Array.new(2, :a)
        assert_equal [{}, {}], registry.lookup(:bar, 2, {}) # Array.new(2, {})
      end

      test "a block can be registered" do
        registry = Type::Registry.new
        registry.register(:foo) do |type, *args|
          [type, args, "block for foo"]
        end
        registry.register(:bar) do |type, *args|
          [type, args, "block for bar"]
        end
        registry.register(:baz) do |type, **kwargs|
          [type, kwargs, "block for baz"]
        end

        assert_equal [:foo, [1], "block for foo"], registry.lookup(:foo, 1)
        assert_equal [:foo, [2], "block for foo"], registry.lookup(:foo, 2)
        assert_equal [:bar, [1, 2, 3], "block for bar"], registry.lookup(:bar, 1, 2, 3)
        assert_equal [:baz, { kw: 1 }, "block for baz"], registry.lookup(:baz, kw: 1)
      end

      test "a reasonable error is given when no type is found" do
        registry = Type::Registry.new

        e = assert_raises(ArgumentError) do
          registry.lookup(:foo)
        end

        assert_equal "Unknown type :foo", e.message
      end
    end
  end
end

reply.rb

# frozen_string_literal: true

require "models/topic"

class Reply < Topic
  validate :errors_on_empty_content
  validate :title_is_wrong_create,  on: :create

  validate :check_empty_title
  validate :check_content_mismatch, on: :create
  validate :check_wrong_update,     on: :update

  def check_empty_title
    errors.add(:title, "is Empty") unless title && title.size > 0
  end

  def errors_on_empty_content
    errors.add(:content, "is Empty") unless content && content.size > 0
  end

  def check_content_mismatch
    if title && content && content == "Mismatch"
      errors.add(:title, "is Content Mismatch")
    end
  end

  def title_is_wrong_create
    errors.add(:title, "is Wrong Create") if title && title == "Wrong Create"
  end

  def check_wrong_update
    errors.add(:title, "is Wrong Update") if title && title == "Wrong Update"
  end
end

secure_password.rb

# frozen_string_literal: true

module ActiveModel
  module SecurePassword
    extend ActiveSupport::Concern

    # BCrypt hash function can handle maximum 72 bytes, and if we pass
    # password of length more than 72 bytes it ignores extra characters.
    # Hence need to put a restriction on password length.
    MAX_PASSWORD_LENGTH_ALLOWED = 72

    class << self
      attr_accessor :min_cost # :nodoc:
    end
    self.min_cost = false

    module ClassMethods
      # Adds methods to set and authenticate against a BCrypt password.
      # This mechanism requires you to have a +XXX_digest+ attribute.
      # Where +XXX+ is the attribute name of your desired password.
      #
      # The following validations are added automatically:
      # * Password must be present on creation
      # * Password length should be less than or equal to 72 bytes
      # * Confirmation of password (using a +XXX_confirmation+ attribute)
      #
      # If confirmation validation is not needed, simply leave out the
      # value for +XXX_confirmation+ (i.e. don't provide a form field for
      # it). When this attribute has a +nil+ value, the validation will not be
      # triggered.
      #
      # For further customizability, it is possible to suppress the default
      # validations by passing <tt>validations: false</tt> as an argument.
      #
      # Add bcrypt (~> 3.1.7) to Gemfile to use #has_secure_password:
      #
      #   gem 'bcrypt', '~> 3.1.7'
      #
      # Example using Active Record (which automatically includes ActiveModel::SecurePassword):
      #
      #   # Schema: User(name:string, password_digest:string, recovery_password_digest:string)
      #   class User < ActiveRecord::Base
      #     has_secure_password
      #     has_secure_password :recovery_password, validations: false
      #   end
      #
      #   user = User.new(name: 'david', password: '', password_confirmation: 'nomatch')
      #   user.save                                                  # => false, password required
      #   user.password = 'mUc3m00RsqyRe'
      #   user.save                                                  # => false, confirmation doesn't match
      #   user.password_confirmation = 'mUc3m00RsqyRe'
      #   user.save                                                  # => true
      #   user.recovery_password = "42password"
      #   user.recovery_password_digest                              # => "$2a$04$iOfhwahFymCs5weB3BNH/uXkTG65HR.qpW.bNhEjFP3ftli3o5DQC"
      #   user.save                                                  # => true
      #   user.authenticate('notright')                              # => false
      #   user.authenticate('mUc3m00RsqyRe')                         # => user
      #   user.authenticate_recovery_password('42password')          # => user
      #   User.find_by(name: 'david')&.authenticate('notright')      # => false
      #   User.find_by(name: 'david')&.authenticate('mUc3m00RsqyRe') # => user
      def has_secure_password(attribute = :password, validations: true)
        # Load bcrypt gem only when has_secure_password is used.
        # This is to avoid ActiveModel (and by extension the entire framework)
        # being dependent on a binary library.
        begin
          require "bcrypt"
        rescue LoadError
          $stderr.puts "You don't have bcrypt installed in your application. Please add it to your Gemfile and run bundle install"
          raise
        end

        include InstanceMethodsOnActivation.new(attribute)

        if validations
          include ActiveModel::Validations

          # This ensures the model has a password by checking whether the password_digest
          # is present, so that this works with both new and existing records. However,
          # when there is an error, the message is added to the password attribute instead
          # so that the error message will make sense to the end-user.
          validate do |record|
            record.errors.add(attribute, :blank) unless record.public_send("#{attribute}_digest").present?
          end

          validates_length_of attribute, maximum: ActiveModel::SecurePassword::MAX_PASSWORD_LENGTH_ALLOWED
          validates_confirmation_of attribute, allow_blank: true
        end
      end
    end

    class InstanceMethodsOnActivation < Module
      def initialize(attribute)
        attr_reader attribute

        define_method("#{attribute}=") do |unencrypted_password|
          if unencrypted_password.nil?
            instance_variable_set("@#{attribute}", nil)
            self.public_send("#{attribute}_digest=", nil)
          elsif !unencrypted_password.empty?
            instance_variable_set("@#{attribute}", unencrypted_password)
            cost = ActiveModel::SecurePassword.min_cost ? BCrypt::Engine::MIN_COST : BCrypt::Engine.cost
            self.public_send("#{attribute}_digest=", BCrypt::Password.create(unencrypted_password, cost: cost))
          end
        end

        define_method("#{attribute}_confirmation=") do |unencrypted_password|
          instance_variable_set("@#{attribute}_confirmation", unencrypted_password)
        end

        # Returns +self+ if the password is correct, otherwise +false+.
        #
        #   class User < ActiveRecord::Base
        #     has_secure_password validations: false
        #   end
        #
        #   user = User.new(name: 'david', password: 'mUc3m00RsqyRe')
        #   user.save
        #   user.authenticate_password('notright')      # => false
        #   user.authenticate_password('mUc3m00RsqyRe') # => user
        define_method("authenticate_#{attribute}") do |unencrypted_password|
          attribute_digest = public_send("#{attribute}_digest")
          attribute_digest.present? && BCrypt::Password.new(attribute_digest).is_password?(unencrypted_password) && self
        end

        alias_method :authenticate, :authenticate_password if attribute == :password
      end
    end
  end
end

secure_password_test.rb

# frozen_string_literal: true

require "cases/helper"
require "models/user"
require "models/visitor"

class SecurePasswordTest < ActiveModel::TestCase
  setup do
    # Used only to speed up tests
    @original_min_cost = ActiveModel::SecurePassword.min_cost
    ActiveModel::SecurePassword.min_cost = true

    @user = User.new
    @visitor = Visitor.new

    # Simulate loading an existing user from the DB
    @existing_user = User.new
    @existing_user.password_digest = BCrypt::Password.create("password", cost: BCrypt::Engine::MIN_COST)
  end

  teardown do
    ActiveModel::SecurePassword.min_cost = @original_min_cost
  end

  test "automatically include ActiveModel::Validations when validations are enabled" do
    assert_respond_to @user, :valid?
  end

  test "don't include ActiveModel::Validations when validations are disabled" do
    assert_not_respond_to @visitor, :valid?
  end

  test "create a new user with validations and valid password/confirmation" do
    @user.password = "password"
    @user.password_confirmation = "password"

    assert @user.valid?(:create), "user should be valid"

    @user.password = "a" * 72
    @user.password_confirmation = "a" * 72

    assert @user.valid?(:create), "user should be valid"
  end

  test "create a new user with validation and a spaces only password" do
    @user.password = " " * 72
    assert @user.valid?(:create), "user should be valid"
  end

  test "create a new user with validation and a blank password" do
    @user.password = ""
    assert_not @user.valid?(:create), "user should be invalid"
    assert_equal 1, @user.errors.count
    assert_equal ["can't be blank"], @user.errors[:password]
  end

  test "create a new user with validation and a nil password" do
    @user.password = nil
    assert_not @user.valid?(:create), "user should be invalid"
    assert_equal 1, @user.errors.count
    assert_equal ["can't be blank"], @user.errors[:password]
  end

  test "create a new user with validation and password length greater than 72" do
    @user.password = "a" * 73
    @user.password_confirmation = "a" * 73
    assert_not @user.valid?(:create), "user should be invalid"
    assert_equal 1, @user.errors.count
    assert_equal ["is too long (maximum is 72 characters)"], @user.errors[:password]
  end

  test "create a new user with validation and a blank password confirmation" do
    @user.password = "password"
    @user.password_confirmation = ""
    assert_not @user.valid?(:create), "user should be invalid"
    assert_equal 1, @user.errors.count
    assert_equal ["doesn't match Password"], @user.errors[:password_confirmation]
  end

  test "create a new user with validation and a nil password confirmation" do
    @user.password = "password"
    @user.password_confirmation = nil
    assert @user.valid?(:create), "user should be valid"
  end

  test "create a new user with validation and an incorrect password confirmation" do
    @user.password = "password"
    @user.password_confirmation = "something else"
    assert_not @user.valid?(:create), "user should be invalid"
    assert_equal 1, @user.errors.count
    assert_equal ["doesn't match Password"], @user.errors[:password_confirmation]
  end

  test "resetting password to nil clears the password cache" do
    @user.password = "password"
    @user.password = nil
    assert_nil @user.password
  end

  test "update an existing user with validation and no change in password" do
    assert @existing_user.valid?(:update), "user should be valid"
  end

  test "update an existing user with validations and valid password/confirmation" do
    @existing_user.password = "password"
    @existing_user.password_confirmation = "password"

    assert @existing_user.valid?(:update), "user should be valid"

    @existing_user.password = "a" * 72
    @existing_user.password_confirmation = "a" * 72

    assert @existing_user.valid?(:update), "user should be valid"
  end

  test "updating an existing user with validation and a blank password" do
    @existing_user.password = ""
    assert @existing_user.valid?(:update), "user should be valid"
  end

  test "updating an existing user with validation and a spaces only password" do
    @user.password = " " * 72
    assert @user.valid?(:update), "user should be valid"
  end

  test "updating an existing user with validation and a blank password and password_confirmation" do
    @existing_user.password = ""
    @existing_user.password_confirmation = ""
    assert @existing_user.valid?(:update), "user should be valid"
  end

  test "updating an existing user with validation and a nil password" do
    @existing_user.password = nil
    assert_not @existing_user.valid?(:update), "user should be invalid"
    assert_equal 1, @existing_user.errors.count
    assert_equal ["can't be blank"], @existing_user.errors[:password]
  end

  test "updating an existing user with validation and password length greater than 72" do
    @existing_user.password = "a" * 73
    @existing_user.password_confirmation = "a" * 73
    assert_not @existing_user.valid?(:update), "user should be invalid"
    assert_equal 1, @existing_user.errors.count
    assert_equal ["is too long (maximum is 72 characters)"], @existing_user.errors[:password]
  end

  test "updating an existing user with validation and a blank password confirmation" do
    @existing_user.password = "password"
    @existing_user.password_confirmation = ""
    assert_not @existing_user.valid?(:update), "user should be invalid"
    assert_equal 1, @existing_user.errors.count
    assert_equal ["doesn't match Password"], @existing_user.errors[:password_confirmation]
  end

  test "updating an existing user with validation and a nil password confirmation" do
    @existing_user.password = "password"
    @existing_user.password_confirmation = nil
    assert @existing_user.valid?(:update), "user should be valid"
  end

  test "updating an existing user with validation and an incorrect password confirmation" do
    @existing_user.password = "password"
    @existing_user.password_confirmation = "something else"
    assert_not @existing_user.valid?(:update), "user should be invalid"
    assert_equal 1, @existing_user.errors.count
    assert_equal ["doesn't match Password"], @existing_user.errors[:password_confirmation]
  end

  test "updating an existing user with validation and a blank password digest" do
    @existing_user.password_digest = ""
    assert_not @existing_user.valid?(:update), "user should be invalid"
    assert_equal 1, @existing_user.errors.count
    assert_equal ["can't be blank"], @existing_user.errors[:password]
  end

  test "updating an existing user with validation and a nil password digest" do
    @existing_user.password_digest = nil
    assert_not @existing_user.valid?(:update), "user should be invalid"
    assert_equal 1, @existing_user.errors.count
    assert_equal ["can't be blank"], @existing_user.errors[:password]
  end

  test "setting a blank password should not change an existing password" do
    @existing_user.password = ""
    assert @existing_user.password_digest == "password"
  end

  test "setting a nil password should clear an existing password" do
    @existing_user.password = nil
    assert_nil @existing_user.password_digest
  end

  test "override secure password attribute" do
    assert_nil @user.password_called

    @user.password = "secret"

    assert_equal "secret", @user.password
    assert_equal 1, @user.password_called

    @user.password = "terces"

    assert_equal "terces", @user.password
    assert_equal 2, @user.password_called
  end

  test "authenticate" do
    @user.password = "secret"
    @user.recovery_password = "42password"

    assert_equal false, @user.authenticate("wrong")
    assert_equal @user, @user.authenticate("secret")

    assert_equal false, @user.authenticate_password("wrong")
    assert_equal @user, @user.authenticate_password("secret")

    assert_equal false, @user.authenticate_recovery_password("wrong")
    assert_equal @user, @user.authenticate_recovery_password("42password")
  end

  test "authenticate should return false and not raise when password digest is blank" do
    @user.password_digest = " "
    assert_equal false, @user.authenticate(" ")
  end

  test "Password digest cost defaults to bcrypt default cost when min_cost is false" do
    ActiveModel::SecurePassword.min_cost = false

    @user.password = "secret"
    assert_equal BCrypt::Engine::DEFAULT_COST, @user.password_digest.cost
  end

  test "Password digest cost honors bcrypt cost attribute when min_cost is false" do
    original_bcrypt_cost = BCrypt::Engine.cost
    ActiveModel::SecurePassword.min_cost = false
    BCrypt::Engine.cost = 5

    @user.password = "secret"
    assert_equal BCrypt::Engine.cost, @user.password_digest.cost
  ensure
    BCrypt::Engine.cost = original_bcrypt_cost
  end

  test "Password digest cost can be set to bcrypt min cost to speed up tests" do
    ActiveModel::SecurePassword.min_cost = true

    @user.password = "secret"
    assert_equal BCrypt::Engine::MIN_COST, @user.password_digest.cost
  end
end

serialization.rb

# frozen_string_literal: true

require "active_support/core_ext/enumerable"

module ActiveModel
  # == Active \Model \Serialization
  #
  # Provides a basic serialization to a serializable_hash for your objects.
  #
  # A minimal implementation could be:
  #
  #   class Person
  #     include ActiveModel::Serialization
  #
  #     attr_accessor :name
  #
  #     def attributes
  #       {'name' => nil}
  #     end
  #   end
  #
  # Which would provide you with:
  #
  #   person = Person.new
  #   person.serializable_hash   # => {"name"=>nil}
  #   person.name = "Bob"
  #   person.serializable_hash   # => {"name"=>"Bob"}
  #
  # An +attributes+ hash must be defined and should contain any attributes you
  # need to be serialized. Attributes must be strings, not symbols.
  # When called, serializable hash will use instance methods that match the name
  # of the attributes hash's keys. In order to override this behavior, take a look
  # at the private method +read_attribute_for_serialization+.
  #
  # ActiveModel::Serializers::JSON module automatically includes
  # the <tt>ActiveModel::Serialization</tt> module, so there is no need to
  # explicitly include <tt>ActiveModel::Serialization</tt>.
  #
  # A minimal implementation including JSON would be:
  #
  #   class Person
  #     include ActiveModel::Serializers::JSON
  #
  #     attr_accessor :name
  #
  #     def attributes
  #       {'name' => nil}
  #     end
  #   end
  #
  # Which would provide you with:
  #
  #   person = Person.new
  #   person.serializable_hash   # => {"name"=>nil}
  #   person.as_json             # => {"name"=>nil}
  #   person.to_json             # => "{\"name\":null}"
  #
  #   person.name = "Bob"
  #   person.serializable_hash   # => {"name"=>"Bob"}
  #   person.as_json             # => {"name"=>"Bob"}
  #   person.to_json             # => "{\"name\":\"Bob\"}"
  #
  # Valid options are <tt>:only</tt>, <tt>:except</tt>, <tt>:methods</tt> and
  # <tt>:include</tt>. The following are all valid examples:
  #
  #   person.serializable_hash(only: 'name')
  #   person.serializable_hash(include: :address)
  #   person.serializable_hash(include: { address: { only: 'city' }})
  module Serialization
    # Returns a serialized hash of your object.
    #
    #   class Person
    #     include ActiveModel::Serialization
    #
    #     attr_accessor :name, :age
    #
    #     def attributes
    #       {'name' => nil, 'age' => nil}
    #     end
    #
    #     def capitalized_name
    #       name.capitalize
    #     end
    #   end
    #
    #   person = Person.new
    #   person.name = 'bob'
    #   person.age  = 22
    #   person.serializable_hash                # => {"name"=>"bob", "age"=>22}
    #   person.serializable_hash(only: :name)   # => {"name"=>"bob"}
    #   person.serializable_hash(except: :name) # => {"age"=>22}
    #   person.serializable_hash(methods: :capitalized_name)
    #   # => {"name"=>"bob", "age"=>22, "capitalized_name"=>"Bob"}
    #
    # Example with <tt>:include</tt> option
    #
    #   class User
    #     include ActiveModel::Serializers::JSON
    #     attr_accessor :name, :notes # Emulate has_many :notes
    #     def attributes
    #       {'name' => nil}
    #     end
    #   end
    #
    #   class Note
    #     include ActiveModel::Serializers::JSON
    #     attr_accessor :title, :text
    #     def attributes
    #       {'title' => nil, 'text' => nil}
    #     end
    #   end
    #
    #   note = Note.new
    #   note.title = 'Battle of Austerlitz'
    #   note.text = 'Some text here'
    #
    #   user = User.new
    #   user.name = 'Napoleon'
    #   user.notes = [note]
    #
    #   user.serializable_hash
    #   # => {"name" => "Napoleon"}
    #   user.serializable_hash(include: { notes: { only: 'title' }})
    #   # => {"name" => "Napoleon", "notes" => [{"title"=>"Battle of Austerlitz"}]}
    def serializable_hash(options = nil)
      attribute_names = self.attribute_names

      return serializable_attributes(attribute_names) if options.blank?

      if only = options[:only]
        attribute_names &= Array(only).map(&:to_s)
      elsif except = options[:except]
        attribute_names -= Array(except).map(&:to_s)
      end

      hash = serializable_attributes(attribute_names)

      Array(options[:methods]).each { |m| hash[m.to_s] = send(m) }

      serializable_add_includes(options) do |association, records, opts|
        hash[association.to_s] = if records.respond_to?(:to_ary)
          records.to_ary.map { |a| a.serializable_hash(opts) }
        else
          records.serializable_hash(opts)
        end
      end

      hash
    end

    # Returns an array of attribute names as strings
    def attribute_names # :nodoc:
      attributes.keys
    end

    private
      # Hook method defining how an attribute value should be retrieved for
      # serialization. By default this is assumed to be an instance named after
      # the attribute. Override this method in subclasses should you need to
      # retrieve the value for a given attribute differently:
      #
      #   class MyClass
      #     include ActiveModel::Serialization
      #
      #     def initialize(data = {})
      #       @data = data
      #     end
      #
      #     def read_attribute_for_serialization(key)
      #       @data[key]
      #     end
      #   end
      alias :read_attribute_for_serialization :send

      def serializable_attributes(attribute_names)
        attribute_names.index_with { |n| read_attribute_for_serialization(n) }
      end

      # Add associations specified via the <tt>:include</tt> option.
      #
      # Expects a block that takes as arguments:
      #   +association+ - name of the association
      #   +records+     - the association record(s) to be serialized
      #   +opts+        - options for the association records
      def serializable_add_includes(options = {}) # :nodoc:
        return unless includes = options[:include]

        unless includes.is_a?(Hash)
          includes = Hash[Array(includes).flat_map { |n| n.is_a?(Hash) ? n.to_a : [[n, {}]] }]
        end

        includes.each do |association, opts|
          if records = send(association)
            yield association, records, opts
          end
        end
      end
  end
end

serialization_test.rb

# frozen_string_literal: true

require "cases/helper"
require "active_support/core_ext/object/instance_variables"

class SerializationTest < ActiveModel::TestCase
  class User
    include ActiveModel::Serialization

    attr_accessor :name, :email, :gender, :address, :friends

    def initialize(name, email, gender)
      @name, @email, @gender = name, email, gender
      @friends = []
    end

    def attributes
      instance_values.except("address", "friends")
    end

    def method_missing(method_name, *args)
      if method_name == :bar
        "i_am_bar"
      else
        super
      end
    end

    def foo
      "i_am_foo"
    end
  end

  class Address
    include ActiveModel::Serialization

    attr_accessor :street, :city, :state, :zip

    def attributes
      instance_values
    end
  end

  setup do
    @user = User.new("David", "david@example.com", "male")
    @user.address = Address.new
    @user.address.street = "123 Lane"
    @user.address.city = "Springfield"
    @user.address.state = "CA"
    @user.address.zip = 11111
    @user.friends = [User.new("Joe", "joe@example.com", "male"),
                     User.new("Sue", "sue@example.com", "female")]
  end

  def test_method_serializable_hash_should_work
    expected = { "name" => "David", "gender" => "male", "email" => "david@example.com" }
    assert_equal expected, @user.serializable_hash
  end

  def test_method_serializable_hash_should_work_with_only_option
    expected = { "name" => "David" }
    assert_equal expected, @user.serializable_hash(only: [:name])
  end

  def test_method_serializable_hash_should_work_with_except_option
    expected = { "gender" => "male", "email" => "david@example.com" }
    assert_equal expected, @user.serializable_hash(except: [:name])
  end

  def test_method_serializable_hash_should_work_with_methods_option
    expected = { "name" => "David", "gender" => "male", "foo" => "i_am_foo", "bar" => "i_am_bar", "email" => "david@example.com" }
    assert_equal expected, @user.serializable_hash(methods: [:foo, :bar])
  end

  def test_method_serializable_hash_should_work_with_only_and_methods
    expected = { "foo" => "i_am_foo", "bar" => "i_am_bar" }
    assert_equal expected, @user.serializable_hash(only: [], methods: [:foo, :bar])
  end

  def test_method_serializable_hash_should_work_with_except_and_methods
    expected = { "gender" => "male", "foo" => "i_am_foo", "bar" => "i_am_bar" }
    assert_equal expected, @user.serializable_hash(except: [:name, :email], methods: [:foo, :bar])
  end

  def test_should_raise_NoMethodError_for_non_existing_method
    assert_raise(NoMethodError) { @user.serializable_hash(methods: [:nada]) }
  end

  def test_should_use_read_attribute_for_serialization
    def @user.read_attribute_for_serialization(n)
      "Jon"
    end

    expected = { "name" => "Jon" }
    assert_equal expected, @user.serializable_hash(only: :name)
  end

  def test_include_option_with_singular_association
    expected = { "name" => "David", "gender" => "male", "email" => "david@example.com",
                "address" => { "street" => "123 Lane", "city" => "Springfield", "state" => "CA", "zip" => 11111 } }
    assert_equal expected, @user.serializable_hash(include: :address)
  end

  def test_include_option_with_plural_association
    expected = { "email" => "david@example.com", "gender" => "male", "name" => "David",
                "friends" => [{ "name" => "Joe", "email" => "joe@example.com", "gender" => "male" },
                           { "name" => "Sue", "email" => "sue@example.com", "gender" => "female" }] }
    assert_equal expected, @user.serializable_hash(include: :friends)
  end

  def test_include_option_with_empty_association
    @user.friends = []
    expected = { "email" => "david@example.com", "gender" => "male", "name" => "David", "friends" => [] }
    assert_equal expected, @user.serializable_hash(include: :friends)
  end

  class FriendList
    def initialize(friends)
      @friends = friends
    end

    def to_ary
      @friends
    end
  end

  def test_include_option_with_ary
    @user.friends = FriendList.new(@user.friends)
    expected = { "email" => "david@example.com", "gender" => "male", "name" => "David",
                "friends" => [{ "name" => "Joe", "email" => "joe@example.com", "gender" => "male" },
                           { "name" => "Sue", "email" => "sue@example.com", "gender" => "female" }] }
    assert_equal expected, @user.serializable_hash(include: :friends)
  end

  def test_multiple_includes
    expected = { "email" => "david@example.com", "gender" => "male", "name" => "David",
                "address" => { "street" => "123 Lane", "city" => "Springfield", "state" => "CA", "zip" => 11111 },
                "friends" => [{ "name" => "Joe", "email" => "joe@example.com", "gender" => "male" },
                           { "name" => "Sue", "email" => "sue@example.com", "gender" => "female" }] }
    assert_equal expected, @user.serializable_hash(include: [:address, :friends])
  end

  def test_include_with_options
    expected = { "email" => "david@example.com", "gender" => "male", "name" => "David",
                "address" => { "street" => "123 Lane" } }
    assert_equal expected, @user.serializable_hash(include: { address: { only: "street" } })
  end

  def test_nested_include
    @user.friends.first.friends = [@user]
    expected = { "email" => "david@example.com", "gender" => "male", "name" => "David",
                "friends" => [{ "name" => "Joe", "email" => "joe@example.com", "gender" => "male",
                            "friends" => [{ "email" => "david@example.com", "gender" => "male", "name" => "David" }] },
                            { "name" => "Sue", "email" => "sue@example.com", "gender" => "female", "friends" => [] }] }
    assert_equal expected, @user.serializable_hash(include: { friends: { include: :friends } })
  end

  def test_only_include
    expected = { "name" => "David", "friends" => [{ "name" => "Joe" }, { "name" => "Sue" }] }
    assert_equal expected, @user.serializable_hash(only: :name, include: { friends: { only: :name } })
  end

  def test_except_include
    expected = { "name" => "David", "email" => "david@example.com",
                "friends" => [{ "name" => "Joe", "email" => "joe@example.com" },
                             { "name" => "Sue", "email" => "sue@example.com" }] }
    assert_equal expected, @user.serializable_hash(except: :gender, include: { friends: { except: :gender } })
  end

  def test_multiple_includes_with_options
    expected = { "email" => "david@example.com", "gender" => "male", "name" => "David",
                "address" => { "street" => "123 Lane" },
                "friends" => [{ "name" => "Joe", "email" => "joe@example.com", "gender" => "male" },
                           { "name" => "Sue", "email" => "sue@example.com", "gender" => "female" }] }
    assert_equal expected, @user.serializable_hash(include: [{ address: { only: "street" } }, :friends])
  end

  def test_all_includes_with_options
    expected = { "email" => "david@example.com", "gender" => "male", "name" => "David",
                "address" => { "street" => "123 Lane" },
                "friends" => [{ "name" => "Joe" }, { "name" => "Sue" }] }
    assert_equal expected, @user.serializable_hash(include: [address: { only: "street" }, friends: { only: "name" }])
  end
end

sheep.rb

# frozen_string_literal: true

class Sheep
  extend ActiveModel::Naming
end

string.rb

# frozen_string_literal: true

require "active_model/type/immutable_string"

module ActiveModel
  module Type
    # Attribute type for strings. It is registered under the +:string+ key.
    #
    # This class is a specialization of ActiveModel::Type::ImmutableString. It
    # performs coercion in the same way, and can be configured in the same way.
    # However, it accounts for mutable strings, so dirty tracking can properly
    # check if a string has changed.
    class String < ImmutableString
      def changed_in_place?(raw_old_value, new_value)
        if new_value.is_a?(::String)
          raw_old_value != new_value
        end
      end

      def to_immutable_string
        ImmutableString.new(
          true: @true,
          false: @false,
          limit: limit,
          precision: precision,
          scale: scale,
        )
      end

      private
        def cast_value(value)
          case value
          when ::String then ::String.new(value)
          when true then @true
          when false then @false
          else value.to_s
          end
        end
    end
  end
end

string_test.rb

# frozen_string_literal: true

require "cases/helper"

module ActiveModel
  module Type
    class StringTest < ActiveModel::TestCase
      test "type casting" do
        type = Type::String.new
        assert_equal "t", type.cast(true)
        assert_equal "f", type.cast(false)
        assert_equal "123", type.cast(123)
      end

      test "type casting for database" do
        type = Type::String.new
        object, array, hash = Object.new, [true], { a: :b }
        assert_equal object, type.serialize(object)
        assert_equal array, type.serialize(array)
        assert_equal hash, type.serialize(hash)
      end

      test "cast strings are mutable" do
        type = Type::String.new

        s = +"foo"
        assert_equal false, type.cast(s).frozen?
        assert_equal false, s.frozen?

        f = -"foo"
        assert_equal false, type.cast(f).frozen?
        assert_equal true, f.frozen?
      end

      test "values are duped coming out" do
        type = Type::String.new

        s = "foo"
        assert_not_same s, type.cast(s)
        assert_equal s, type.cast(s)
        assert_not_same s, type.deserialize(s)
        assert_equal s, type.deserialize(s)
      end
    end
  end
end

time.rb

# frozen_string_literal: true

module ActiveModel
  module Type
    # Attribute type for time representation. It is registered under the
    # +:time+ key.
    #
    #   class Event
    #     include ActiveModel::Attributes
    #
    #     attribute :start, :time
    #   end
    #
    #   event = Event.new
    #   event.start = "2022-02-18T13:15:00-05:00"
    #
    #   event.start.class # => Time
    #   event.start.year  # => 2022
    #   event.start.month # => 2
    #   event.start.day   # => 18
    #   event.start.hour  # => 13
    #   event.start.min   # => 15
    #   event.start.sec   # => 0
    #   event.start.zone  # => "EST"
    #
    # String values are parsed using the ISO 8601 datetime format. Partial
    # time-only formats are also accepted.
    #
    #   event.start = "06:07:08+09:00"
    #   event.start.utc # => 1999-12-31 21:07:08 UTC
    #
    # The degree of sub-second precision can be customized when declaring an
    # attribute:
    #
    #   class Event
    #     include ActiveModel::Attributes
    #
    #     attribute :start, :time, precision: 4
    #   end
    class Time < Value
      include Helpers::Timezone
      include Helpers::TimeValue
      include Helpers::AcceptsMultiparameterTime.new(
        defaults: { 1 => 2000, 2 => 1, 3 => 1, 4 => 0, 5 => 0 }
      )

      def type
        :time
      end

      def user_input_in_time_zone(value)
        return unless value.present?

        case value
        when ::String
          value = "2000-01-01 #{value}"
          time_hash = ::Date._parse(value)
          return if time_hash[:hour].nil?
        when ::Time
          value = value.change(year: 2000, day: 1, month: 1)
        end

        super(value)
      end

      private
        def cast_value(value)
          return apply_seconds_precision(value) unless value.is_a?(::String)
          return if value.empty?

          dummy_time_value = value.sub(/\A\d{4}-\d\d-\d\d(?:T|\s)|/, "2000-01-01 ")

          fast_string_to_time(dummy_time_value) || begin
            time_hash = ::Date._parse(dummy_time_value)
            return if time_hash[:hour].nil?
            new_time(*time_hash.values_at(:year, :mon, :mday, :hour, :min, :sec, :sec_fraction, :offset))
          end
        end
    end
  end
end

time_test.rb

# frozen_string_literal: true

require "cases/helper"

module ActiveModel
  module Type
    class TimeTest < ActiveModel::TestCase
      def test_type_cast_time
        type = Type::Time.new
        assert_nil type.cast(nil)
        assert_nil type.cast("")
        assert_nil type.cast("ABC")

        time_string = ::Time.now.utc.strftime("%T")
        assert_equal time_string, type.cast(time_string).strftime("%T")

        assert_equal ::Time.utc(2000,  1,  1, 16, 45, 54), type.cast("2015-06-13T19:45:54+03:00")
        assert_equal ::Time.utc(1999, 12, 31, 21,  7,  8), type.cast("06:07:08+09:00")
        assert_equal ::Time.utc(2000,  1,  1, 16, 45, 54), type.cast(4 => 16, 5 => 45, 6 => 54)
      end

      def test_user_input_in_time_zone
        ::Time.use_zone("Pacific Time (US & Canada)") do
          type = Type::Time.new
          assert_nil type.user_input_in_time_zone(nil)
          assert_nil type.user_input_in_time_zone("")
          assert_nil type.user_input_in_time_zone("ABC")

          offset = ::Time.zone.formatted_offset
          time_string = "2015-02-09T19:45:54#{offset}"

          assert_equal 19, type.user_input_in_time_zone(time_string).hour
          assert_equal offset, type.user_input_in_time_zone(time_string).formatted_offset
        end
      end
    end
  end
end

time_value.rb

# frozen_string_literal: true

require "active_support/core_ext/string/zones"
require "active_support/core_ext/time/zones"

module ActiveModel
  module Type
    module Helpers # :nodoc: all
      module TimeValue
        def serialize(value)
          value = apply_seconds_precision(value)

          if value.acts_like?(:time)
            if is_utc?
              value = value.getutc if !value.utc?
            else
              value = value.getlocal
            end
          end

          value
        end

        def apply_seconds_precision(value)
          return value unless precision && value.respond_to?(:nsec)

          number_of_insignificant_digits = 9 - precision
          round_power = 10**number_of_insignificant_digits
          rounded_off_nsec = value.nsec % round_power

          if rounded_off_nsec > 0
            value.change(nsec: value.nsec - rounded_off_nsec)
          else
            value
          end
        end

        def type_cast_for_schema(value)
          value.to_fs(:db).inspect
        end

        def user_input_in_time_zone(value)
          value.in_time_zone
        end

        private
          def new_time(year, mon, mday, hour, min, sec, microsec, offset = nil)
            # Treat 0000-00-00 00:00:00 as nil.
            return if year.nil? || (year == 0 && mon == 0 && mday == 0)

            if offset
              time = ::Time.utc(year, mon, mday, hour, min, sec, microsec) rescue nil
              return unless time

              time -= offset unless offset == 0
              is_utc? ? time : time.getlocal
            elsif is_utc?
              ::Time.utc(year, mon, mday, hour, min, sec, microsec) rescue nil
            else
              ::Time.local(year, mon, mday, hour, min, sec, microsec) rescue nil
            end
          end

          ISO_DATETIME = /
            \A
            (\d{4})-(\d\d)-(\d\d)(?:T|\s)            # 2020-06-20T
            (\d\d):(\d\d):(\d\d)(?:\.(\d{1,6})\d*)?  # 10:20:30.123456
            (?:(Z(?=\z)|[+-]\d\d)(?::?(\d\d))?)?     # +09:00
            \z
          /x

          def fast_string_to_time(string)
            return unless ISO_DATETIME =~ string

            usec = $7.to_i
            usec_len = $7&.length
            if usec_len&.< 6
              usec *= 10**(6 - usec_len)
            end

            if $8
              offset = $8 == "Z" ? 0 : $8.to_i * 3600 + $9.to_i * 60
            end

            new_time($1.to_i, $2.to_i, $3.to_i, $4.to_i, $5.to_i, $6.to_i, usec, offset)
          end
      end
    end
  end
end

timezone.rb

# frozen_string_literal: true

require "active_support/core_ext/time/zones"

module ActiveModel
  module Type
    module Helpers # :nodoc: all
      module Timezone
        def is_utc?
          ::Time.zone_default.nil? || ::Time.zone_default.match?("UTC")
        end

        def default_timezone
          is_utc? ? :utc : :local
        end
      end
    end
  end
end

topic.rb

# frozen_string_literal: true

class Topic
  include ActiveModel::Validations
  include ActiveModel::Validations::Callbacks
  include ActiveModel::AttributeMethods
  include ActiveSupport::NumberHelper

  attribute_method_suffix "_before_type_cast", parameters: false
  define_attribute_method :price

  def self._validates_default_keys
    super | [ :message ]
  end

  attr_accessor :title, :author_name, :content, :approved, :created_at
  attr_accessor :after_validation_performed
  attr_writer :price

  after_validation :perform_after_validation

  def initialize(attributes = {})
    attributes.each do |key, value|
      public_send "#{key}=", value
    end
  end

  def condition_is_true
    true
  end

  def condition_is_false
    false
  end

  def perform_after_validation
    self.after_validation_performed = true
  end

  def my_validation
    errors.add :title, "is missing" unless title
  end

  def my_validation_with_arg(attr)
    errors.add attr, "is missing" unless public_send(attr)
  end

  def price
    number_to_currency @price
  end

  def attribute_before_type_cast(attr)
    instance_variable_get(:"@#{attr}")
  end

  private
    def five
      5
    end
end

track_back.rb

# frozen_string_literal: true

class Post
  class TrackBack
    def to_model
      NamedTrackBack.new
    end
  end

  class NamedTrackBack
    extend ActiveModel::Naming
  end
end

translation.rb

# frozen_string_literal: true

module ActiveModel
  # == Active \Model \Translation
  #
  # Provides integration between your object and the Rails internationalization
  # (i18n) framework.
  #
  # A minimal implementation could be:
  #
  #   class TranslatedPerson
  #     extend ActiveModel::Translation
  #   end
  #
  #   TranslatedPerson.human_attribute_name('my_attribute')
  #   # => "My attribute"
  #
  # This also provides the required class methods for hooking into the
  # Rails internationalization API, including being able to define a
  # class-based +i18n_scope+ and +lookup_ancestors+ to find translations in
  # parent classes.
  module Translation
    include ActiveModel::Naming

    # Returns the +i18n_scope+ for the class. Override if you want custom lookup.
    def i18n_scope
      :activemodel
    end

    # When localizing a string, it goes through the lookup returned by this
    # method, which is used in ActiveModel::Name#human,
    # ActiveModel::Errors#full_messages and
    # ActiveModel::Translation#human_attribute_name.
    def lookup_ancestors
      ancestors.select { |x| x.respond_to?(:model_name) }
    end

    MISSING_TRANSLATION = Object.new # :nodoc:

    # Transforms attribute names into a more human format, such as "First name"
    # instead of "first_name".
    #
    #   Person.human_attribute_name("first_name") # => "First name"
    #
    # Specify +options+ with additional translating options.
    def human_attribute_name(attribute, options = {})
      attribute = attribute.to_s

      if attribute.include?(".")
        namespace, _, attribute = attribute.rpartition(".")
        namespace.tr!(".", "/")

        defaults = lookup_ancestors.map do |klass|
          :"#{i18n_scope}.attributes.#{klass.model_name.i18n_key}/#{namespace}.#{attribute}"
        end
        defaults << :"#{i18n_scope}.attributes.#{namespace}.#{attribute}"
      else
        defaults = lookup_ancestors.map do |klass|
          :"#{i18n_scope}.attributes.#{klass.model_name.i18n_key}.#{attribute}"
        end
      end

      defaults << :"attributes.#{attribute}"
      defaults << options[:default] if options[:default]
      defaults << MISSING_TRANSLATION

      translation = I18n.translate(defaults.shift, count: 1, **options, default: defaults)
      translation = attribute.humanize if translation == MISSING_TRANSLATION
      translation
    end
  end
end

translation_test.rb

# frozen_string_literal: true

require "cases/helper"
require "models/person"

class ActiveModelI18nTests < ActiveModel::TestCase
  def setup
    I18n.backend = I18n::Backend::Simple.new
  end

  def teardown
    I18n.backend.reload!
  end

  def test_translated_model_attributes
    I18n.backend.store_translations "en", activemodel: { attributes: { person: { name: "person name attribute" } } }
    assert_equal "person name attribute", Person.human_attribute_name("name")
  end

  def test_translated_model_attributes_with_default
    I18n.backend.store_translations "en", attributes: { name: "name default attribute" }
    assert_equal "name default attribute", Person.human_attribute_name("name")
  end

  def test_translated_model_attributes_using_default_option
    assert_equal "name default attribute", Person.human_attribute_name("name", default: "name default attribute")
  end

  def test_translated_model_attributes_using_default_option_as_symbol
    I18n.backend.store_translations "en", default_name: "name default attribute"
    assert_equal "name default attribute", Person.human_attribute_name("name", default: :default_name)
  end

  def test_translated_model_attributes_falling_back_to_default
    assert_equal "Name", Person.human_attribute_name("name")
  end

  def test_translated_model_attributes_using_default_option_as_symbol_and_falling_back_to_default
    assert_equal "Name", Person.human_attribute_name("name", default: :default_name)
  end

  def test_translated_model_attributes_with_symbols
    I18n.backend.store_translations "en", activemodel: { attributes: { person: { name: "person name attribute" } } }
    assert_equal "person name attribute", Person.human_attribute_name(:name)
  end

  def test_translated_model_attributes_with_ancestor
    I18n.backend.store_translations "en", activemodel: { attributes: { child: { name: "child name attribute" } } }
    assert_equal "child name attribute", Child.human_attribute_name("name")
  end

  def test_translated_model_attributes_with_ancestors_fallback
    I18n.backend.store_translations "en", activemodel: { attributes: { person: { name: "person name attribute" } } }
    assert_equal "person name attribute", Child.human_attribute_name("name")
  end

  def test_translated_model_attributes_with_attribute_matching_namespaced_model_name
    I18n.backend.store_translations "en", activemodel: { attributes: {
      person: { gender: "person gender" },
      "person/gender": { attribute: "person gender attribute" }
    } }

    assert_equal "person gender", Person.human_attribute_name("gender")
    assert_equal "person gender attribute", Person::Gender.human_attribute_name("attribute")
  end

  def test_translated_deeply_nested_model_attributes
    I18n.backend.store_translations "en", activemodel: { attributes: { "person/contacts/addresses": { street: "Deeply Nested Address Street" } } }
    assert_equal "Deeply Nested Address Street", Person.human_attribute_name("contacts.addresses.street")
  end

  def test_translated_nested_model_attributes
    I18n.backend.store_translations "en", activemodel: { attributes: { "person/addresses": { street: "Person Address Street" } } }
    assert_equal "Person Address Street", Person.human_attribute_name("addresses.street")
  end

  def test_translated_nested_model_attributes_with_namespace_fallback
    I18n.backend.store_translations "en", activemodel: { attributes: { addresses: { street: "Cool Address Street" } } }
    assert_equal "Cool Address Street", Person.human_attribute_name("addresses.street")
  end

  def test_translated_model_names
    I18n.backend.store_translations "en", activemodel: { models: { person: "person model" } }
    assert_equal "person model", Person.model_name.human
  end

  def test_translated_model_when_missing_translation
    assert_equal "Person", Person.model_name.human
  end

  def test_translated_model_with_namespace
    I18n.backend.store_translations "en", activemodel: { models: { 'person/gender': "gender model" } }
    assert_equal "gender model", Person::Gender.model_name.human
  end

  def test_translated_subclass_model
    I18n.backend.store_translations "en", activemodel: { models: { child: "child model" } }
    assert_equal "child model", Child.model_name.human
  end

  def test_translated_subclass_model_when_ancestor_translation
    I18n.backend.store_translations "en", activemodel: { models: { person: "person model" } }
    assert_equal "person model", Child.model_name.human
  end

  def test_translated_subclass_model_when_missing_translation
    assert_equal "Child", Child.model_name.human
  end

  def test_translated_model_with_default_value_when_missing_translation
    assert_equal "dude", Person.model_name.human(default: "dude")
  end

  def test_translated_model_with_default_key_when_missing_both_translations
    assert_equal "Person", Person.model_name.human(default: :this_key_does_not_exist)
  end

  def test_human_does_not_modify_options
    options = { default: "person model" }
    Person.model_name.human(options)
    assert_equal({ default: "person model" }, options)
  end

  def test_human_attribute_name_does_not_modify_options
    options = { default: "Cool gender" }
    Person.human_attribute_name("gender", options)
    assert_equal({ default: "Cool gender" }, options)
  end
end

type.rb

# frozen_string_literal: true

require "active_model/type/helpers"
require "active_model/type/value"

require "active_model/type/big_integer"
require "active_model/type/binary"
require "active_model/type/boolean"
require "active_model/type/date"
require "active_model/type/date_time"
require "active_model/type/decimal"
require "active_model/type/float"
require "active_model/type/immutable_string"
require "active_model/type/integer"
require "active_model/type/string"
require "active_model/type/time"

require "active_model/type/registry"

module ActiveModel
  module Type
    @registry = Registry.new

    class << self
      attr_accessor :registry # :nodoc:

      # Add a new type to the registry, allowing it to be referenced as a
      # symbol by {attribute}[rdoc-ref:Attributes::ClassMethods#attribute].
      def register(type_name, klass = nil, &block)
        registry.register(type_name, klass, &block)
      end

      def lookup(...) # :nodoc:
        registry.lookup(...)
      end

      def default_value # :nodoc:
        @default_value ||= Value.new
      end
    end

    register(:big_integer, Type::BigInteger)
    register(:binary, Type::Binary)
    register(:boolean, Type::Boolean)
    register(:date, Type::Date)
    register(:datetime, Type::DateTime)
    register(:decimal, Type::Decimal)
    register(:float, Type::Float)
    register(:immutable_string, Type::ImmutableString)
    register(:integer, Type::Integer)
    register(:string, Type::String)
    register(:time, Type::Time)
  end
end

type_test.rb

# frozen_string_literal: true

require "cases/helper"

module ActiveModel
  class TypeTest < ActiveModel::TestCase
    setup do
      @old_registry = ActiveModel::Type.registry
      ActiveModel::Type.registry = @old_registry.dup
    end

    teardown do
      ActiveModel::Type.registry = @old_registry
    end

    test "registering a new type" do
      type = Struct.new(:args)
      ActiveModel::Type.register(:foo, type)

      assert_equal type.new(:arg), ActiveModel::Type.lookup(:foo, :arg)
      assert_equal type.new({}), ActiveModel::Type.lookup(:foo, {})
    end
  end
end

user.rb

# frozen_string_literal: true

class User
  extend ActiveModel::Callbacks
  include ActiveModel::SecurePassword

  define_model_callbacks :create

  has_secure_password
  has_secure_password :recovery_password, validations: false

  attr_accessor :password_digest, :recovery_password_digest
  attr_accessor :password_called

  def password=(unencrypted_password)
    self.password_called ||= 0
    self.password_called += 1
    super
  end
end

user_provided_default.rb

# frozen_string_literal: true

require "active_model/attribute"

module ActiveModel
  class Attribute # :nodoc:
    class UserProvidedDefault < FromUser # :nodoc:
      def initialize(name, value, type, database_default)
        @user_provided_value = value
        super(name, value, type, database_default)
      end

      def value_before_type_cast
        if user_provided_value.is_a?(Proc)
          @memoized_value_before_type_cast ||= user_provided_value.call
        else
          @user_provided_value
        end
      end

      def with_type(type)
        self.class.new(name, user_provided_value, type, original_attribute)
      end

      def marshal_dump
        result = [
          name,
          value_before_type_cast,
          type,
          original_attribute,
        ]
        result << value if defined?(@value)
        result
      end

      def marshal_load(values)
        name, user_provided_value, type, original_attribute, value = values
        @name = name
        @user_provided_value = user_provided_value
        @type = type
        @original_attribute = original_attribute
        if values.length == 5
          @value = value
        end
      end

      private
        attr_reader :user_provided_value
    end
  end
end

validates.rb

# frozen_string_literal: true

require "active_support/core_ext/hash/slice"

module ActiveModel
  module Validations
    module ClassMethods
      # This method is a shortcut to all default validators and any custom
      # validator classes ending in 'Validator'. Note that Rails default
      # validators can be overridden inside specific classes by creating
      # custom validator classes in their place such as PresenceValidator.
      #
      # Examples of using the default rails validators:
      #
      #   validates :username, absence: true
      #   validates :terms, acceptance: true
      #   validates :password, confirmation: true
      #   validates :username, exclusion: { in: %w(admin superuser) }
      #   validates :email, format: { with: /\A([^@\s]+)@((?:[-a-z0-9]+\.)+[a-z]{2,})\z/i, on: :create }
      #   validates :age, inclusion: { in: 0..9 }
      #   validates :first_name, length: { maximum: 30 }
      #   validates :age, numericality: true
      #   validates :username, presence: true
      #
      # The power of the +validates+ method comes when using custom validators
      # and default validators in one call for a given attribute.
      #
      #   class EmailValidator < ActiveModel::EachValidator
      #     def validate_each(record, attribute, value)
      #       record.errors.add attribute, (options[:message] || "is not an email") unless
      #         /\A([^@\s]+)@((?:[-a-z0-9]+\.)+[a-z]{2,})\z/i.match?(value)
      #     end
      #   end
      #
      #   class Person
      #     include ActiveModel::Validations
      #     attr_accessor :name, :email
      #
      #     validates :name, presence: true, length: { maximum: 100 }
      #     validates :email, presence: true, email: true
      #   end
      #
      # Validator classes may also exist within the class being validated
      # allowing custom modules of validators to be included as needed.
      #
      #   class Film
      #     include ActiveModel::Validations
      #
      #     class TitleValidator < ActiveModel::EachValidator
      #       def validate_each(record, attribute, value)
      #         record.errors.add attribute, "must start with 'the'" unless /\Athe/i.match?(value)
      #       end
      #     end
      #
      #     validates :name, title: true
      #   end
      #
      # Additionally validator classes may be in another namespace and still
      # used within any class.
      #
      #   validates :name, :'film/title' => true
      #
      # The validators hash can also handle regular expressions, ranges, arrays
      # and strings in shortcut form.
      #
      #   validates :email, format: /@/
      #   validates :role, inclusion: %w(admin contributor)
      #   validates :password, length: 6..20
      #
      # When using shortcut form, ranges and arrays are passed to your
      # validator's initializer as <tt>options[:in]</tt> while other types
      # including regular expressions and strings are passed as <tt>options[:with]</tt>.
      #
      # There is also a list of options that could be used along with validators:
      #
      # * <tt>:on</tt> - Specifies the contexts where this validation is active.
      #   Runs in all validation contexts by default +nil+. You can pass a symbol
      #   or an array of symbols. (e.g. <tt>on: :create</tt> or
      #   <tt>on: :custom_validation_context</tt> or
      #   <tt>on: [:create, :custom_validation_context]</tt>)
      # * <tt>:if</tt> - Specifies a method, proc, or string to call to determine
      #   if the validation should occur (e.g. <tt>if: :allow_validation</tt>,
      #   or <tt>if: Proc.new { |user| user.signup_step > 2 }</tt>). The method,
      #   proc or string should return or evaluate to a +true+ or +false+ value.
      # * <tt>:unless</tt> - Specifies a method, proc, or string to call to determine
      #   if the validation should not occur (e.g. <tt>unless: :skip_validation</tt>,
      #   or <tt>unless: Proc.new { |user| user.signup_step <= 2 }</tt>). The
      #   method, proc, or string should return or evaluate to a +true+ or
      #   +false+ value.
      # * <tt>:allow_nil</tt> - Skip validation if the attribute is +nil+.
      # * <tt>:allow_blank</tt> - Skip validation if the attribute is blank.
      # * <tt>:strict</tt> - If the <tt>:strict</tt> option is set to true
      #   will raise ActiveModel::StrictValidationFailed instead of adding the error.
      #   <tt>:strict</tt> option can also be set to any other exception.
      #
      # Example:
      #
      #   validates :password, presence: true, confirmation: true, if: :password_required?
      #   validates :token, length: 24, strict: TokenLengthException
      #
      #
      # Finally, the options +:if+, +:unless+, +:on+, +:allow_blank+, +:allow_nil+, +:strict+
      # and +:message+ can be given to one specific validator, as a hash:
      #
      #   validates :password, presence: { if: :password_required?, message: 'is forgotten.' }, confirmation: true
      def validates(*attributes)
        defaults = attributes.extract_options!.dup
        validations = defaults.slice!(*_validates_default_keys)

        raise ArgumentError, "You need to supply at least one attribute" if attributes.empty?
        raise ArgumentError, "You need to supply at least one validation" if validations.empty?

        defaults[:attributes] = attributes

        validations.each do |key, options|
          key = "#{key.to_s.camelize}Validator"

          begin
            validator = key.include?("::") ? key.constantize : const_get(key)
          rescue NameError
            raise ArgumentError, "Unknown validator: '#{key}'"
          end

          next unless options

          validates_with(validator, defaults.merge(_parse_validates_options(options)))
        end
      end

      # This method is used to define validations that cannot be corrected by end
      # users and are considered exceptional. So each validator defined with bang
      # or <tt>:strict</tt> option set to <tt>true</tt> will always raise
      # <tt>ActiveModel::StrictValidationFailed</tt> instead of adding error
      # when validation fails. See <tt>validates</tt> for more information about
      # the validation itself.
      #
      #   class Person
      #     include ActiveModel::Validations
      #
      #     attr_accessor :name
      #     validates! :name, presence: true
      #   end
      #
      #   person = Person.new
      #   person.name = ''
      #   person.valid?
      #   # => ActiveModel::StrictValidationFailed: Name can't be blank
      def validates!(*attributes)
        options = attributes.extract_options!
        options[:strict] = true
        validates(*(attributes << options))
      end

    private
      # When creating custom validators, it might be useful to be able to specify
      # additional default keys. This can be done by overwriting this method.
      def _validates_default_keys
        [:if, :unless, :on, :allow_blank, :allow_nil, :strict]
      end

      def _parse_validates_options(options)
        case options
        when TrueClass
          {}
        when Hash
          options
        when Range, Array
          { in: options }
        else
          { with: options }
        end
      end
    end
  end
end

validates_test.rb

# frozen_string_literal: true

require "cases/helper"
require "models/person"
require "models/topic"
require "models/person_with_validator"
require "validators/namespace/email_validator"

class ValidatesTest < ActiveModel::TestCase
  setup :reset_callbacks
  teardown :reset_callbacks

  def reset_callbacks
    Person.clear_validators!
    Topic.clear_validators!
    PersonWithValidator.clear_validators!
  end

  def test_validates_with_messages_empty
    Person.validates :title, presence: { message: "" }
    person = Person.new
    assert_not person.valid?, "person should not be valid."
  end

  def test_validates_with_built_in_validation
    Person.validates :title, numericality: true
    person = Person.new
    person.valid?
    assert_equal ["is not a number"], person.errors[:title]
  end

  def test_validates_with_attribute_specified_as_string
    Person.validates "title", numericality: true
    person = Person.new
    person.valid?
    assert_equal ["is not a number"], person.errors[:title]

    person = Person.new
    person.title = 123
    assert_predicate person, :valid?
  end

  def test_validates_with_built_in_validation_and_options
    Person.validates :salary, numericality: { message: "my custom message" }
    person = Person.new
    person.valid?
    assert_equal ["my custom message"], person.errors[:salary]
  end

  def test_validates_with_validator_class
    Person.validates :karma, email: true
    person = Person.new
    person.valid?
    assert_equal ["is not an email"], person.errors[:karma]
  end

  def test_validates_with_namespaced_validator_class
    Person.validates :karma, 'namespace/email': true
    person = Person.new
    person.valid?
    assert_equal ["is not an email"], person.errors[:karma]
  end

  def test_validates_with_if_as_local_conditions
    Person.validates :karma, presence: true, email: { if: :condition_is_false }
    person = Person.new
    person.valid?
    assert_equal ["can't be blank"], person.errors[:karma]
  end

  def test_validates_with_if_as_shared_conditions
    Person.validates :karma, presence: true, email: true, if: :condition_is_false
    person = Person.new
    assert_predicate person, :valid?
  end

  def test_validates_with_unless_as_local_conditions
    Person.validates :karma, presence: true, email: { unless: :condition_is_true }
    person = Person.new
    person.valid?
    assert_equal ["can't be blank"], person.errors[:karma]
  end

  def test_validates_with_unless_shared_conditions
    Person.validates :karma, presence: true, email: true, unless: :condition_is_true
    person = Person.new
    assert_predicate person, :valid?
  end

  def test_validates_with_allow_nil_shared_conditions
    Person.validates :karma, length: { minimum: 20 }, email: true, allow_nil: true
    person = Person.new
    assert_predicate person, :valid?
  end

  def test_validates_with_regexp
    Person.validates :karma, format: /positive|negative/
    person = Person.new
    assert_predicate person, :invalid?
    assert_equal ["is invalid"], person.errors[:karma]
    person.karma = "positive"
    assert_predicate person, :valid?
  end

  def test_validates_with_array
    Person.validates :gender, inclusion: %w(m f)
    person = Person.new
    assert_predicate person, :invalid?
    assert_equal ["is not included in the list"], person.errors[:gender]
    person.gender = "m"
    assert_predicate person, :valid?
  end

  def test_validates_with_range
    Person.validates :karma, length: 6..20
    person = Person.new
    assert_predicate person, :invalid?
    assert_equal ["is too short (minimum is 6 characters)"], person.errors[:karma]
    person.karma = "something"
    assert_predicate person, :valid?
  end

  def test_validates_with_validator_class_and_options
    Person.validates :karma, email: { message: "my custom message" }
    person = Person.new
    person.valid?
    assert_equal ["my custom message"], person.errors[:karma]
  end

  def test_validates_with_unknown_validator
    assert_raise(ArgumentError) { Person.validates :karma, unknown: true }
  end

  def test_validates_with_disabled_unknown_validator
    assert_raise(ArgumentError) { Person.validates :karma, unknown: false }
  end

  def test_validates_with_included_validator
    PersonWithValidator.validates :title, presence: true
    person = PersonWithValidator.new
    person.valid?
    assert_equal ["Local validator"], person.errors[:title]
  end

  def test_validates_with_included_validator_and_options
    PersonWithValidator.validates :title, presence: { custom: " please" }
    person = PersonWithValidator.new
    person.valid?
    assert_equal ["Local validator please"], person.errors[:title]
  end

  def test_validates_with_included_validator_and_wildcard_shortcut
    # Shortcut for PersonWithValidator.validates :title, like: { with: "Mr." }
    PersonWithValidator.validates :title, like: "Mr."
    person = PersonWithValidator.new
    person.title = "Ms. Pacman"
    person.valid?
    assert_equal ["does not appear to be like Mr."], person.errors[:title]
  end

  def test_defining_extra_default_keys_for_validates
    Topic.validates :title, confirmation: true, message: "Y U NO CONFIRM"
    topic = Topic.new
    topic.title = "What's happening"
    topic.title_confirmation = "Not this"
    assert_not_predicate topic, :valid?
    assert_equal ["Y U NO CONFIRM"], topic.errors[:title_confirmation]
  end
end

validations.rb

# frozen_string_literal: true

require "active_support/core_ext/array/extract_options"

module ActiveModel
  # == Active \Model \Validations
  #
  # Provides a full validation framework to your objects.
  #
  # A minimal implementation could be:
  #
  #   class Person
  #     include ActiveModel::Validations
  #
  #     attr_accessor :first_name, :last_name
  #
  #     validates_each :first_name, :last_name do |record, attr, value|
  #       record.errors.add attr, "starts with z." if value.start_with?("z")
  #     end
  #   end
  #
  # Which provides you with the full standard validation stack that you
  # know from Active Record:
  #
  #   person = Person.new
  #   person.valid?                   # => true
  #   person.invalid?                 # => false
  #
  #   person.first_name = 'zoolander'
  #   person.valid?                   # => false
  #   person.invalid?                 # => true
  #   person.errors.messages          # => {first_name:["starts with z."]}
  #
  # Note that <tt>ActiveModel::Validations</tt> automatically adds an +errors+
  # method to your instances initialized with a new ActiveModel::Errors
  # object, so there is no need for you to do this manually.
  module Validations
    extend ActiveSupport::Concern

    included do
      extend ActiveModel::Naming
      extend ActiveModel::Callbacks
      extend ActiveModel::Translation

      extend  HelperMethods
      include HelperMethods

      attr_accessor :validation_context
      private :validation_context=
      define_callbacks :validate, scope: :name

      class_attribute :_validators, instance_writer: false, default: Hash.new { |h, k| h[k] = [] }
    end

    module ClassMethods
      # Validates each attribute against a block.
      #
      #   class Person
      #     include ActiveModel::Validations
      #
      #     attr_accessor :first_name, :last_name
      #
      #     validates_each :first_name, :last_name, allow_blank: true do |record, attr, value|
      #       record.errors.add attr, "starts with z." if value.start_with?("z")
      #     end
      #   end
      #
      # Options:
      # * <tt>:on</tt> - Specifies the contexts where this validation is active.
      #   Runs in all validation contexts by default +nil+. You can pass a symbol
      #   or an array of symbols. (e.g. <tt>on: :create</tt> or
      #   <tt>on: :custom_validation_context</tt> or
      #   <tt>on: [:create, :custom_validation_context]</tt>)
      # * <tt>:allow_nil</tt> - Skip validation if attribute is +nil+.
      # * <tt>:allow_blank</tt> - Skip validation if attribute is blank.
      # * <tt>:if</tt> - Specifies a method, proc, or string to call to determine
      #   if the validation should occur (e.g. <tt>if: :allow_validation</tt>,
      #   or <tt>if: Proc.new { |user| user.signup_step > 2 }</tt>). The method,
      #   proc or string should return or evaluate to a +true+ or +false+ value.
      # * <tt>:unless</tt> - Specifies a method, proc, or string to call to
      #   determine if the validation should not occur (e.g. <tt>unless: :skip_validation</tt>,
      #   or <tt>unless: Proc.new { |user| user.signup_step <= 2 }</tt>). The
      #   method, proc, or string should return or evaluate to a +true+ or +false+
      #   value.
      def validates_each(*attr_names, &block)
        validates_with BlockValidator, _merge_attributes(attr_names), &block
      end

      VALID_OPTIONS_FOR_VALIDATE = [:on, :if, :unless, :prepend].freeze # :nodoc:

      # Adds a validation method or block to the class. This is useful when
      # overriding the +validate+ instance method becomes too unwieldy and
      # you're looking for more descriptive declaration of your validations.
      #
      # This can be done with a symbol pointing to a method:
      #
      #   class Comment
      #     include ActiveModel::Validations
      #
      #     validate :must_be_friends
      #
      #     def must_be_friends
      #       errors.add(:base, 'Must be friends to leave a comment') unless commenter.friend_of?(commentee)
      #     end
      #   end
      #
      # With a block which is passed with the current record to be validated:
      #
      #   class Comment
      #     include ActiveModel::Validations
      #
      #     validate do |comment|
      #       comment.must_be_friends
      #     end
      #
      #     def must_be_friends
      #       errors.add(:base, 'Must be friends to leave a comment') unless commenter.friend_of?(commentee)
      #     end
      #   end
      #
      # Or with a block where +self+ points to the current record to be validated:
      #
      #   class Comment
      #     include ActiveModel::Validations
      #
      #     validate do
      #       errors.add(:base, 'Must be friends to leave a comment') unless commenter.friend_of?(commentee)
      #     end
      #   end
      #
      # Note that the return value of validation methods is not relevant.
      # It's not possible to halt the validate callback chain.
      #
      # Options:
      # * <tt>:on</tt> - Specifies the contexts where this validation is active.
      #   Runs in all validation contexts by default +nil+. You can pass a symbol
      #   or an array of symbols. (e.g. <tt>on: :create</tt> or
      #   <tt>on: :custom_validation_context</tt> or
      #   <tt>on: [:create, :custom_validation_context]</tt>)
      # * <tt>:if</tt> - Specifies a method, proc, or string to call to determine
      #   if the validation should occur (e.g. <tt>if: :allow_validation</tt>,
      #   or <tt>if: Proc.new { |user| user.signup_step > 2 }</tt>). The method,
      #   proc or string should return or evaluate to a +true+ or +false+ value.
      # * <tt>:unless</tt> - Specifies a method, proc, or string to call to
      #   determine if the validation should not occur (e.g. <tt>unless: :skip_validation</tt>,
      #   or <tt>unless: Proc.new { |user| user.signup_step <= 2 }</tt>). The
      #   method, proc, or string should return or evaluate to a +true+ or +false+
      #   value.
      #
      # NOTE: Calling +validate+ multiple times on the same method will overwrite previous definitions.
      #
      def validate(*args, &block)
        options = args.extract_options!

        if args.all?(Symbol)
          options.each_key do |k|
            unless VALID_OPTIONS_FOR_VALIDATE.include?(k)
              raise ArgumentError.new("Unknown key: #{k.inspect}. Valid keys are: #{VALID_OPTIONS_FOR_VALIDATE.map(&:inspect).join(', ')}. Perhaps you meant to call `validates` instead of `validate`?")
            end
          end
        end

        if options.key?(:on)
          options = options.dup
          options[:on] = Array(options[:on])
          options[:if] = [
            ->(o) { !(options[:on] & Array(o.validation_context)).empty? },
            *options[:if]
          ]
        end

        set_callback(:validate, *args, options, &block)
      end

      # List all validators that are being used to validate the model using
      # +validates_with+ method.
      #
      #   class Person
      #     include ActiveModel::Validations
      #
      #     validates_with MyValidator
      #     validates_with OtherValidator, on: :create
      #     validates_with StrictValidator, strict: true
      #   end
      #
      #   Person.validators
      #   # => [
      #   #      #<MyValidator:0x007fbff403e808 @options={}>,
      #   #      #<OtherValidator:0x007fbff403d930 @options={on: :create}>,
      #   #      #<StrictValidator:0x007fbff3204a30 @options={strict:true}>
      #   #    ]
      def validators
        _validators.values.flatten.uniq
      end

      # Clears all of the validators and validations.
      #
      # Note that this will clear anything that is being used to validate
      # the model for both the +validates_with+ and +validate+ methods.
      # It clears the validators that are created with an invocation of
      # +validates_with+ and the callbacks that are set by an invocation
      # of +validate+.
      #
      #   class Person
      #     include ActiveModel::Validations
      #
      #     validates_with MyValidator
      #     validates_with OtherValidator, on: :create
      #     validates_with StrictValidator, strict: true
      #     validate :cannot_be_robot
      #
      #     def cannot_be_robot
      #       errors.add(:base, 'A person cannot be a robot') if person_is_robot
      #     end
      #   end
      #
      #   Person.validators
      #   # => [
      #   #      #<MyValidator:0x007fbff403e808 @options={}>,
      #   #      #<OtherValidator:0x007fbff403d930 @options={on: :create}>,
      #   #      #<StrictValidator:0x007fbff3204a30 @options={strict:true}>
      #   #    ]
      #
      # If one runs <tt>Person.clear_validators!</tt> and then checks to see what
      # validators this class has, you would obtain:
      #
      #   Person.validators # => []
      #
      # Also, the callback set by <tt>validate :cannot_be_robot</tt> will be erased
      # so that:
      #
      #   Person._validate_callbacks.empty?  # => true
      #
      def clear_validators!
        reset_callbacks(:validate)
        _validators.clear
      end

      # List all validators that are being used to validate a specific attribute.
      #
      #   class Person
      #     include ActiveModel::Validations
      #
      #     attr_accessor :name, :age
      #
      #     validates_presence_of :name
      #     validates_inclusion_of :age, in: 0..99
      #   end
      #
      #   Person.validators_on(:name)
      #   # => [
      #   #       #<ActiveModel::Validations::PresenceValidator:0x007fe604914e60 @attributes=[:name], @options={}>,
      #   #    ]
      def validators_on(*attributes)
        attributes.flat_map do |attribute|
          _validators[attribute.to_sym]
        end
      end

      # Returns +true+ if +attribute+ is an attribute method, +false+ otherwise.
      #
      #  class Person
      #    include ActiveModel::Validations
      #
      #    attr_accessor :name
      #  end
      #
      #  User.attribute_method?(:name) # => true
      #  User.attribute_method?(:age)  # => false
      def attribute_method?(attribute)
        method_defined?(attribute)
      end

      # Copy validators on inheritance.
      def inherited(base) # :nodoc:
        dup = _validators.dup
        base._validators = dup.each { |k, v| dup[k] = v.dup }
        super
      end
    end

    # Clean the +Errors+ object if instance is duped.
    def initialize_dup(other) # :nodoc:
      @errors = nil
      super
    end

    # Returns the +Errors+ object that holds all information about attribute
    # error messages.
    #
    #   class Person
    #     include ActiveModel::Validations
    #
    #     attr_accessor :name
    #     validates_presence_of :name
    #   end
    #
    #   person = Person.new
    #   person.valid? # => false
    #   person.errors # => #<ActiveModel::Errors:0x007fe603816640 @messages={name:["can't be blank"]}>
    def errors
      @errors ||= Errors.new(self)
    end

    # Runs all the specified validations and returns +true+ if no errors were
    # added otherwise +false+.
    #
    #   class Person
    #     include ActiveModel::Validations
    #
    #     attr_accessor :name
    #     validates_presence_of :name
    #   end
    #
    #   person = Person.new
    #   person.name = ''
    #   person.valid? # => false
    #   person.name = 'david'
    #   person.valid? # => true
    #
    # Context can optionally be supplied to define which callbacks to test
    # against (the context is defined on the validations using <tt>:on</tt>).
    #
    #   class Person
    #     include ActiveModel::Validations
    #
    #     attr_accessor :name
    #     validates_presence_of :name, on: :new
    #   end
    #
    #   person = Person.new
    #   person.valid?       # => true
    #   person.valid?(:new) # => false
    def valid?(context = nil)
      current_context, self.validation_context = validation_context, context
      errors.clear
      run_validations!
    ensure
      self.validation_context = current_context
    end

    alias_method :validate, :valid?

    # Performs the opposite of <tt>valid?</tt>. Returns +true+ if errors were
    # added, +false+ otherwise.
    #
    #   class Person
    #     include ActiveModel::Validations
    #
    #     attr_accessor :name
    #     validates_presence_of :name
    #   end
    #
    #   person = Person.new
    #   person.name = ''
    #   person.invalid? # => true
    #   person.name = 'david'
    #   person.invalid? # => false
    #
    # Context can optionally be supplied to define which callbacks to test
    # against (the context is defined on the validations using <tt>:on</tt>).
    #
    #   class Person
    #     include ActiveModel::Validations
    #
    #     attr_accessor :name
    #     validates_presence_of :name, on: :new
    #   end
    #
    #   person = Person.new
    #   person.invalid?       # => false
    #   person.invalid?(:new) # => true
    def invalid?(context = nil)
      !valid?(context)
    end

    # Runs all the validations within the specified context. Returns +true+ if
    # no errors are found, raises +ValidationError+ otherwise.
    #
    # Validations with no <tt>:on</tt> option will run no matter the context. Validations with
    # some <tt>:on</tt> option will only run in the specified context.
    def validate!(context = nil)
      valid?(context) || raise_validation_error
    end

    # Hook method defining how an attribute value should be retrieved. By default
    # this is assumed to be an instance named after the attribute. Override this
    # method in subclasses should you need to retrieve the value for a given
    # attribute differently:
    #
    #   class MyClass
    #     include ActiveModel::Validations
    #
    #     def initialize(data = {})
    #       @data = data
    #     end
    #
    #     def read_attribute_for_validation(key)
    #       @data[key]
    #     end
    #   end
    alias :read_attribute_for_validation :send

  private
    def run_validations!
      _run_validate_callbacks
      errors.empty?
    end

    def raise_validation_error # :doc:
      raise(ValidationError.new(self))
    end
  end

  # = Active Model ValidationError
  #
  # Raised by <tt>validate!</tt> when the model is invalid. Use the
  # +model+ method to retrieve the record which did not validate.
  #
  #   begin
  #     complex_operation_that_internally_calls_validate!
  #   rescue ActiveModel::ValidationError => invalid
  #     puts invalid.model.errors
  #   end
  class ValidationError < StandardError
    attr_reader :model

    def initialize(model)
      @model = model
      errors = @model.errors.full_messages.join(", ")
      super(I18n.t(:"#{@model.class.i18n_scope}.errors.messages.model_invalid", errors: errors, default: :"errors.messages.model_invalid"))
    end
  end
end

Dir[File.expand_path("validations/*.rb", __dir__)].each { |file| require file }

validations_context_test.rb

# frozen_string_literal: true

require "cases/helper"

require "models/topic"

class ValidationsContextTest < ActiveModel::TestCase
  def teardown
    Topic.clear_validators!
  end

  ERROR_MESSAGE = "Validation error from validator"
  ANOTHER_ERROR_MESSAGE = "Another validation error from validator"

  class ValidatorThatAddsErrors < ActiveModel::Validator
    def validate(record)
      record.errors.add(:base, ERROR_MESSAGE)
    end
  end

  class AnotherValidatorThatAddsErrors < ActiveModel::Validator
    def validate(record)
      record.errors.add(:base, ANOTHER_ERROR_MESSAGE)
    end
  end

  test "with a class that adds errors on create and validating a new model with no arguments" do
    Topic.validates_with(ValidatorThatAddsErrors, on: :create)
    topic = Topic.new
    assert topic.valid?, "Validation doesn't run on valid? if 'on' is set to create"
  end

  test "with a class that adds errors on update and validating a new model" do
    Topic.validates_with(ValidatorThatAddsErrors, on: :update)
    topic = Topic.new
    assert topic.valid?(:create), "Validation doesn't run on create if 'on' is set to update"
  end

  test "with a class that adds errors on create and validating a new model" do
    Topic.validates_with(ValidatorThatAddsErrors, on: :create)
    topic = Topic.new
    assert topic.invalid?(:create), "Validation does run on create if 'on' is set to create"
    assert_includes topic.errors[:base], ERROR_MESSAGE
  end

  test "with a class that adds errors on multiple contexts and validating a new model" do
    Topic.validates_with(ValidatorThatAddsErrors, on: [:context1, :context2])

    topic = Topic.new
    assert topic.valid?, "Validation ran with no context given when 'on' is set to context1 and context2"

    assert topic.invalid?(:context1), "Validation did not run on context1 when 'on' is set to context1 and context2"
    assert_includes topic.errors[:base], ERROR_MESSAGE

    assert topic.invalid?(:context2), "Validation did not run on context2 when 'on' is set to context1 and context2"
    assert_includes topic.errors[:base], ERROR_MESSAGE
  end

  test "with a class that validating a model for a multiple contexts" do
    Topic.validates_with(ValidatorThatAddsErrors, on: :context1)
    Topic.validates_with(AnotherValidatorThatAddsErrors, on: :context2)

    topic = Topic.new
    assert topic.valid?, "Validation ran with no context given when 'on' is set to context1 and context2"

    assert topic.invalid?([:context1, :context2]), "Validation did not run on context1 when 'on' is set to context1 and context2"
    assert_includes topic.errors[:base], ERROR_MESSAGE
    assert_includes topic.errors[:base], ANOTHER_ERROR_MESSAGE
  end
end

validations_test.rb

# frozen_string_literal: true

require "cases/helper"

require "models/topic"
require "models/reply"
require "models/custom_reader"

require "active_support/json"
require "active_support/xml_mini"

class ValidationsTest < ActiveModel::TestCase
  class CustomStrictValidationException < StandardError; end

  def teardown
    Topic.clear_validators!
  end

  def test_single_field_validation
    r = Reply.new
    r.title = "There's no content!"
    assert r.invalid?, "A reply without content should be invalid"
    assert r.after_validation_performed, "after_validation callback should be called"

    r.content = "Messa content!"
    assert r.valid?, "A reply with content should be valid"
    assert r.after_validation_performed, "after_validation callback should be called"
  end

  def test_single_attr_validation_and_error_msg
    r = Reply.new
    r.title = "There's no content!"
    assert_predicate r, :invalid?
    assert r.errors[:content].any?, "A reply without content should mark that attribute as invalid"
    assert_equal ["is Empty"], r.errors["content"], "A reply without content should contain an error"
    assert_equal 1, r.errors.count
  end

  def test_double_attr_validation_and_error_msg
    r = Reply.new
    assert_predicate r, :invalid?

    assert r.errors[:title].any?, "A reply without title should mark that attribute as invalid"
    assert_equal ["is Empty"], r.errors["title"], "A reply without title should contain an error"

    assert r.errors[:content].any?, "A reply without content should mark that attribute as invalid"
    assert_equal ["is Empty"], r.errors["content"], "A reply without content should contain an error"

    assert_equal 2, r.errors.count
  end

  def test_multiple_errors_per_attr_iteration_with_full_error_composition
    r = Reply.new
    r.title   = ""
    r.content = ""
    r.valid?

    errors = r.errors.to_a

    assert_equal "Content is Empty", errors[0]
    assert_equal "Title is Empty", errors[1]
    assert_equal 2, r.errors.count
  end

  def test_errors_on_nested_attributes_expands_name
    t = Topic.new
    t.errors.add("replies.name", "can't be blank")
    assert_equal ["Replies name can't be blank"], t.errors.full_messages
  end

  def test_errors_on_base
    r = Reply.new
    r.content = "Mismatch"
    r.valid?
    r.errors.add(:base, "Reply is not dignifying")

    errors = r.errors.to_a.inject([]) { |result, error| result + [error] }

    assert_equal ["Reply is not dignifying"], r.errors[:base]

    assert_includes errors, "Title is Empty"
    assert_includes errors, "Reply is not dignifying"
    assert_equal 2, r.errors.count
  end

  def test_errors_on_base_with_symbol_message
    r = Reply.new
    r.content = "Mismatch"
    r.valid?
    r.errors.add(:base, :invalid)

    errors = r.errors.to_a.inject([]) { |result, error| result + [error] }

    assert_equal ["is invalid"], r.errors[:base]

    assert_includes errors, "Title is Empty"
    assert_includes errors, "is invalid"

    assert_equal 2, r.errors.count
  end

  def test_errors_empty_after_errors_on_check
    t = Topic.new
    assert_empty t.errors[:id]
    assert_empty t.errors
  end

  def test_validates_each
    hits = 0
    Topic.validates_each(:title, :content, [:title, :content]) do |record, attr|
      record.errors.add attr, "gotcha"
      hits += 1
    end
    t = Topic.new("title" => "valid", "content" => "whatever")
    assert_predicate t, :invalid?
    assert_equal 4, hits
    assert_equal %w(gotcha gotcha), t.errors[:title]
    assert_equal %w(gotcha gotcha), t.errors[:content]
  end

  def test_validates_each_custom_reader
    hits = 0
    CustomReader.validates_each(:title, :content, [:title, :content]) do |record, attr|
      record.errors.add attr, "gotcha"
      hits += 1
    end
    t = CustomReader.new("title" => "valid", "content" => "whatever")
    assert_predicate t, :invalid?
    assert_equal 4, hits
    assert_equal %w(gotcha gotcha), t.errors[:title]
    assert_equal %w(gotcha gotcha), t.errors[:content]
  ensure
    CustomReader.clear_validators!
  end

  def test_validate_block
    Topic.validate { errors.add("title", "will never be valid") }
    t = Topic.new("title" => "Title", "content" => "whatever")
    assert_predicate t, :invalid?
    assert_predicate t.errors[:title], :any?
    assert_equal ["will never be valid"], t.errors["title"]
  end

  def test_validate_block_with_params
    Topic.validate { |topic| topic.errors.add("title", "will never be valid") }
    t = Topic.new("title" => "Title", "content" => "whatever")
    assert_predicate t, :invalid?
    assert_predicate t.errors[:title], :any?
    assert_equal ["will never be valid"], t.errors["title"]
  end

  def test_validates_with_array_condition_does_not_mutate_the_array
    opts = []
    Topic.validate(if: opts, on: :create) { }
    assert_empty opts
  end

  def test_invalid_validator
    Topic.validate :i_dont_exist
    assert_raises(NoMethodError) do
      t = Topic.new
      t.valid?
    end
  end

  def test_invalid_options_to_validate
    error = assert_raises(ArgumentError) do
      # A common mistake -- we meant to call 'validates'
      Topic.validate :title, presence: true
    end
    message = "Unknown key: :presence. Valid keys are: :on, :if, :unless, :prepend. Perhaps you meant to call `validates` instead of `validate`?"
    assert_equal message, error.message
  end

  def test_callback_options_to_validate
    klass = Class.new(Topic) do
      attr_reader :call_sequence

      def initialize(*)
        super
        @call_sequence = []
      end

      private
        def validator_a
          @call_sequence << :a
        end

        def validator_b
          @call_sequence << :b
        end

        def validator_c
          @call_sequence << :c
        end
    end

    assert_nothing_raised do
      klass.validate :validator_a, if: -> { true }
      klass.validate :validator_b, prepend: true
      klass.validate :validator_c, unless: -> { true }
    end

    t = klass.new

    assert_predicate t, :valid?
    assert_equal [:b, :a], t.call_sequence
  end

  def test_errors_to_json
    Topic.validates_presence_of %w(title content)
    t = Topic.new
    assert_predicate t, :invalid?

    hash = {}
    hash[:title] = ["can't be blank"]
    hash[:content] = ["can't be blank"]
    assert_equal t.errors.to_json, hash.to_json
  end

  def test_validation_order
    Topic.validates_presence_of :title
    Topic.validates_length_of :title, minimum: 2

    t = Topic.new("title" => "")
    assert_predicate t, :invalid?
    assert_equal "can't be blank", t.errors["title"].first
    Topic.validates_presence_of :title, :author_name
    Topic.validate { errors.add("author_email_address", "will never be valid") }
    Topic.validates_length_of :title, :content, minimum: 2

    t = Topic.new title: ""
    assert_predicate t, :invalid?

    assert_equal :title, key = t.errors.attribute_names[0]
    assert_equal "can't be blank", t.errors[key][0]
    assert_equal "is too short (minimum is 2 characters)", t.errors[key][1]
    assert_equal :author_name, key = t.errors.attribute_names[1]
    assert_equal "can't be blank", t.errors[key][0]
    assert_equal :author_email_address, key = t.errors.attribute_names[2]
    assert_equal "will never be valid", t.errors[key][0]
    assert_equal :content, key = t.errors.attribute_names[3]
    assert_equal "is too short (minimum is 2 characters)", t.errors[key][0]
  end

  def test_validation_with_if_and_on
    Topic.validates_presence_of :title, if: Proc.new { |x| x.author_name = "bad"; true }, on: :update

    t = Topic.new(title: "")

    # If block should not fire
    assert_predicate t, :valid?
    assert_predicate t.author_name, :nil?

    # If block should fire
    assert t.invalid?(:update)
    assert t.author_name == "bad"
  end

  def test_invalid_should_be_the_opposite_of_valid
    Topic.validates_presence_of :title

    t = Topic.new
    assert_predicate t, :invalid?
    assert_predicate t.errors[:title], :any?

    t.title = "Things are going to change"
    assert_not_predicate t, :invalid?
  end

  def test_validation_with_message_as_proc
    Topic.validates_presence_of(:title, message: proc { "no blanks here".upcase })

    t = Topic.new
    assert_predicate t, :invalid?
    assert_equal ["NO BLANKS HERE"], t.errors[:title]
  end

  def test_list_of_validators_for_model
    Topic.validates_presence_of :title
    Topic.validates_length_of :title, minimum: 2

    assert_equal 2, Topic.validators.count
    assert_equal [:presence, :length], Topic.validators.map(&:kind)
  end

  def test_list_of_validators_on_an_attribute
    Topic.validates_presence_of :title, :content
    Topic.validates_length_of :title, minimum: 2

    assert_equal 2, Topic.validators_on(:title).count
    assert_equal [:presence, :length], Topic.validators_on(:title).map(&:kind)
    assert_equal 1, Topic.validators_on(:content).count
    assert_equal [:presence], Topic.validators_on(:content).map(&:kind)
  end

  def test_accessing_instance_of_validator_on_an_attribute
    Topic.validates_length_of :title, minimum: 10
    assert_equal 10, Topic.validators_on(:title).first.options[:minimum]
  end

  def test_list_of_validators_on_multiple_attributes
    Topic.validates :title, length: { minimum: 10 }
    Topic.validates :author_name, presence: true, format: /a/

    validators = Topic.validators_on(:title, :author_name)

    assert_equal [
      ActiveModel::Validations::FormatValidator,
      ActiveModel::Validations::LengthValidator,
      ActiveModel::Validations::PresenceValidator
    ], validators.map(&:class).sort_by(&:to_s)
  end

  def test_list_of_validators_will_be_empty_when_empty
    Topic.validates :title, length: { minimum: 10 }
    assert_equal [], Topic.validators_on(:author_name)
  end

  def test_validations_on_the_instance_level
    Topic.validates :title, :author_name, presence: true
    Topic.validates :content, length: { minimum: 10 }

    topic = Topic.new
    assert_predicate topic, :invalid?
    assert_equal 3, topic.errors.size

    topic.title = "Some Title"
    topic.author_name = "Some Author"
    topic.content = "Some Content Whose Length is more than 10."
    assert_predicate topic, :valid?
  end

  def test_validate
    Topic.validate do
      validates_presence_of :title, :author_name
      validates_length_of :content, minimum: 10
    end

    topic = Topic.new
    assert_empty topic.errors

    topic.validate
    assert_not_empty topic.errors
  end

  def test_validate_with_bang
    Topic.validates :title, presence: true

    assert_raise(ActiveModel::ValidationError) do
      Topic.new.validate!
    end
  end

  def test_validate_with_bang_and_context
    Topic.validates :title, presence: true, on: :context

    assert_raise(ActiveModel::ValidationError) do
      Topic.new.validate!(:context)
    end

    t = Topic.new(title: "Valid title")
    assert t.validate!(:context)
  end

  def test_strict_validation_in_validates
    Topic.validates :title, strict: true, presence: true
    assert_raises ActiveModel::StrictValidationFailed do
      Topic.new.valid?
    end
  end

  def test_strict_validation_not_fails
    Topic.validates :title, strict: true, presence: true
    assert_predicate Topic.new(title: "hello"), :valid?
  end

  def test_strict_validation_particular_validator
    Topic.validates :title, presence: { strict: true }
    assert_raises ActiveModel::StrictValidationFailed do
      Topic.new.valid?
    end
  end

  def test_strict_validation_in_custom_validator_helper
    Topic.validates_presence_of :title, strict: true
    assert_raises ActiveModel::StrictValidationFailed do
      Topic.new.valid?
    end
  end

  def test_strict_validation_custom_exception
    Topic.validates_presence_of :title, strict: CustomStrictValidationException
    assert_raises CustomStrictValidationException do
      Topic.new.valid?
    end
  end

  def test_validates_with_bang
    Topic.validates! :title, presence: true
    assert_raises ActiveModel::StrictValidationFailed do
      Topic.new.valid?
    end
  end

  def test_validates_with_false_hash_value
    Topic.validates :title, presence: false
    assert_predicate Topic.new, :valid?
  end

  def test_strict_validation_error_message
    Topic.validates :title, strict: true, presence: true

    exception = assert_raises(ActiveModel::StrictValidationFailed) do
      Topic.new.valid?
    end
    assert_equal "Title can't be blank", exception.message
  end

  def test_does_not_modify_options_argument
    options = { presence: true }
    Topic.validates :title, options
    assert_equal({ presence: true }, options)
  end

  def test_dup_validity_is_independent
    Topic.validates_presence_of :title
    topic = Topic.new("title" => "Literature")
    topic.valid?

    duped = topic.dup
    duped.title = nil
    assert_predicate duped, :invalid?

    topic.title = nil
    duped.title = "Mathematics"
    assert_predicate topic, :invalid?
    assert_predicate duped, :valid?
  end

  def test_validation_with_message_as_proc_that_takes_a_record_as_a_parameter
    Topic.validates_presence_of(:title, message: proc { |record| "You have failed me for the last time, #{record.author_name}." })

    t = Topic.new(author_name: "Admiral")
    assert_predicate t, :invalid?
    assert_equal ["You have failed me for the last time, Admiral."], t.errors[:title]
  end

  def test_validation_with_message_as_proc_that_takes_record_and_data_as_a_parameters
    Topic.validates_presence_of(:title, message: proc { |record, data| "#{data[:attribute]} is missing. You have failed me for the last time, #{record.author_name}." })

    t = Topic.new(author_name: "Admiral")
    assert_predicate t, :invalid?
    assert_equal ["Title is missing. You have failed me for the last time, Admiral."], t.errors[:title]
  end
end

validator.rb

# frozen_string_literal: true

require "active_support/core_ext/module/anonymous"

module ActiveModel
  # == Active \Model \Validator
  #
  # A simple base class that can be used along with
  # ActiveModel::Validations::ClassMethods.validates_with
  #
  #   class Person
  #     include ActiveModel::Validations
  #     validates_with MyValidator
  #   end
  #
  #   class MyValidator < ActiveModel::Validator
  #     def validate(record)
  #       if some_complex_logic
  #         record.errors.add(:base, "This record is invalid")
  #       end
  #     end
  #
  #     private
  #       def some_complex_logic
  #         # ...
  #       end
  #   end
  #
  # Any class that inherits from ActiveModel::Validator must implement a method
  # called +validate+ which accepts a +record+.
  #
  #   class Person
  #     include ActiveModel::Validations
  #     validates_with MyValidator
  #   end
  #
  #   class MyValidator < ActiveModel::Validator
  #     def validate(record)
  #       record # => The person instance being validated
  #       options # => Any non-standard options passed to validates_with
  #     end
  #   end
  #
  # To cause a validation error, you must add to the +record+'s errors directly
  # from within the validators message.
  #
  #   class MyValidator < ActiveModel::Validator
  #     def validate(record)
  #       record.errors.add :base, "This is some custom error message"
  #       record.errors.add :first_name, "This is some complex validation"
  #       # etc...
  #     end
  #   end
  #
  # To add behavior to the initialize method, use the following signature:
  #
  #   class MyValidator < ActiveModel::Validator
  #     def initialize(options)
  #       super
  #       @my_custom_field = options[:field_name] || :first_name
  #     end
  #   end
  #
  # Note that the validator is initialized only once for the whole application
  # life cycle, and not on each validation run.
  #
  # The easiest way to add custom validators for validating individual attributes
  # is with the convenient ActiveModel::EachValidator.
  #
  #   class TitleValidator < ActiveModel::EachValidator
  #     def validate_each(record, attribute, value)
  #       record.errors.add attribute, 'must be Mr., Mrs., or Dr.' unless %w(Mr. Mrs. Dr.).include?(value)
  #     end
  #   end
  #
  # This can now be used in combination with the +validates+ method
  # (see ActiveModel::Validations::ClassMethods#validates for more on this).
  #
  #   class Person
  #     include ActiveModel::Validations
  #     attr_accessor :title
  #
  #     validates :title, presence: true, title: true
  #   end
  #
  # It can be useful to access the class that is using that validator when there are prerequisites such
  # as an +attr_accessor+ being present. This class is accessible via <tt>options[:class]</tt> in the constructor.
  # To set up your validator override the constructor.
  #
  #   class MyValidator < ActiveModel::Validator
  #     def initialize(options={})
  #       super
  #       options[:class].attr_accessor :custom_attribute
  #     end
  #   end
  class Validator
    attr_reader :options

    # Returns the kind of the validator.
    #
    #   PresenceValidator.kind   # => :presence
    #   AcceptanceValidator.kind # => :acceptance
    def self.kind
      @kind ||= name.split("::").last.underscore.chomp("_validator").to_sym unless anonymous?
    end

    # Accepts options that will be made available through the +options+ reader.
    def initialize(options = {})
      @options = options.except(:class).freeze
    end

    # Returns the kind for this validator.
    #
    #   PresenceValidator.new(attributes: [:username]).kind # => :presence
    #   AcceptanceValidator.new(attributes: [:terms]).kind  # => :acceptance
    def kind
      self.class.kind
    end

    # Override this method in subclasses with validation logic, adding errors
    # to the records +errors+ array where necessary.
    def validate(record)
      raise NotImplementedError, "Subclasses must implement a validate(record) method."
    end
  end

  # +EachValidator+ is a validator which iterates through the attributes given
  # in the options hash invoking the <tt>validate_each</tt> method passing in the
  # record, attribute, and value.
  #
  # All \Active \Model validations are built on top of this validator.
  class EachValidator < Validator
    attr_reader :attributes

    # Returns a new validator instance. All options will be available via the
    # +options+ reader, however the <tt>:attributes</tt> option will be removed
    # and instead be made available through the +attributes+ reader.
    def initialize(options)
      @attributes = Array(options.delete(:attributes))
      raise ArgumentError, ":attributes cannot be blank" if @attributes.empty?
      super
      check_validity!
    end

    # Performs validation on the supplied record. By default this will call
    # +validate_each+ to determine validity therefore subclasses should
    # override +validate_each+ with validation logic.
    def validate(record)
      attributes.each do |attribute|
        value = record.read_attribute_for_validation(attribute)
        next if (value.nil? && options[:allow_nil]) || (value.blank? && options[:allow_blank])
        value = prepare_value_for_validation(value, record, attribute)
        validate_each(record, attribute, value)
      end
    end

    # Override this method in subclasses with the validation logic, adding
    # errors to the records +errors+ array where necessary.
    def validate_each(record, attribute, value)
      raise NotImplementedError, "Subclasses must implement a validate_each(record, attribute, value) method"
    end

    # Hook method that gets called by the initializer allowing verification
    # that the arguments supplied are valid. You could for example raise an
    # +ArgumentError+ when invalid options are supplied.
    def check_validity!
    end

    private
      def prepare_value_for_validation(value, record, attr_name)
        value
      end
  end

  # +BlockValidator+ is a special +EachValidator+ which receives a block on initialization
  # and call this block for each attribute being validated. +validates_each+ uses this validator.
  class BlockValidator < EachValidator # :nodoc:
    def initialize(options, &block)
      @block = block
      super
    end

    private
      def validate_each(record, attribute, value)
        @block.call(record, attribute, value)
      end
  end
end

value.rb

# frozen_string_literal: true

module ActiveModel
  module Type
    # The base class for all attribute types. This class also serves as the
    # default type for attributes that do not specify a type.
    class Value
      attr_reader :precision, :scale, :limit

      # Initializes a type with three basic configuration settings: precision,
      # limit, and scale. The Value base class does not define behavior for
      # these settings. It uses them for equality comparison and hash key
      # generation only.
      def initialize(precision: nil, limit: nil, scale: nil)
        @precision = precision
        @scale = scale
        @limit = limit
      end

      # Returns true if this type can convert +value+ to a type that is usable
      # by the database.  For example a boolean type can return +true+ if the
      # value parameter is a Ruby boolean, but may return +false+ if the value
      # parameter is some other object.
      def serializable?(value)
        true
      end

      # Returns the unique type name as a Symbol. Subclasses should override
      # this method.
      def type
      end

      # Converts a value from database input to the appropriate ruby type. The
      # return value of this method will be returned from
      # ActiveRecord::AttributeMethods::Read#read_attribute. The default
      # implementation just calls Value#cast.
      #
      # +value+ The raw input, as provided from the database.
      def deserialize(value)
        cast(value)
      end

      # Type casts a value from user input (e.g. from a setter). This value may
      # be a string from the form builder, or a ruby object passed to a setter.
      # There is currently no way to differentiate between which source it came
      # from.
      #
      # The return value of this method will be returned from
      # ActiveRecord::AttributeMethods::Read#read_attribute. See also:
      # Value#cast_value.
      #
      # +value+ The raw input, as provided to the attribute setter.
      def cast(value)
        cast_value(value) unless value.nil?
      end

      # Casts a value from the ruby type to a type that the database knows how
      # to understand. The returned value from this method should be a
      # +String+, +Numeric+, +Date+, +Time+, +Symbol+, +true+, +false+, or
      # +nil+.
      def serialize(value)
        value
      end

      # Type casts a value for schema dumping. This method is private, as we are
      # hoping to remove it entirely.
      def type_cast_for_schema(value) # :nodoc:
        value.inspect
      end

      # These predicates are not documented, as I need to look further into
      # their use, and see if they can be removed entirely.
      def binary? # :nodoc:
        false
      end

      # Determines whether a value has changed for dirty checking. +old_value+
      # and +new_value+ will always be type-cast. Types should not need to
      # override this method.
      def changed?(old_value, new_value, _new_value_before_type_cast)
        old_value != new_value
      end

      # Determines whether the mutable value has been modified since it was
      # read. Returns +false+ by default. If your type returns an object
      # which could be mutated, you should override this method. You will need
      # to either:
      #
      # - pass +new_value+ to Value#serialize and compare it to
      #   +raw_old_value+
      #
      # or
      #
      # - pass +raw_old_value+ to Value#deserialize and compare it to
      #   +new_value+
      #
      # +raw_old_value+ The original value, before being passed to
      # +deserialize+.
      #
      # +new_value+ The current value, after type casting.
      def changed_in_place?(raw_old_value, new_value)
        false
      end

      def value_constructed_by_mass_assignment?(_value) # :nodoc:
        false
      end

      def force_equality?(_value) # :nodoc:
        false
      end

      def map(value) # :nodoc:
        yield value
      end

      def ==(other)
        self.class == other.class &&
          precision == other.precision &&
          scale == other.scale &&
          limit == other.limit
      end
      alias eql? ==

      def hash
        [self.class, precision, scale, limit].hash
      end

      def assert_valid_value(_)
      end

      private
        # Convenience method for types which do not need separate type casting
        # behavior for user and database inputs. Called by Value#cast for
        # values except +nil+.
        def cast_value(value) # :doc:
          value
        end
    end
  end
end

value_test.rb

# frozen_string_literal: true

require "cases/helper"

module ActiveModel
  module Type
    class ValueTest < ActiveModel::TestCase
      def test_type_equality
        assert_equal Type::Value.new, Type::Value.new
        assert_not_equal Type::Value.new, Type::Integer.new
        assert_not_equal Type::Value.new(precision: 1), Type::Value.new(precision: 2)
      end
    end
  end
end

version.rb

# frozen_string_literal: true

require_relative "gem_version"

module ActiveModel
  # Returns the version of the currently loaded \Active \Model as a <tt>Gem::Version</tt>
  def self.version
    gem_version
  end
end

visitor.rb

# frozen_string_literal: true

class Visitor
  extend ActiveModel::Callbacks
  include ActiveModel::SecurePassword

  define_model_callbacks :create

  has_secure_password(validations: false)

  attr_accessor :password_digest
  attr_reader :password_confirmation
end

with.rb

# frozen_string_literal: true

require "active_support/core_ext/array/extract_options"

module ActiveModel
  module Validations
    class WithValidator < EachValidator # :nodoc:
      def validate_each(record, attr, val)
        method_name = options[:with]

        if record.method(method_name).arity == 0
          record.send method_name
        else
          record.send method_name, attr
        end
      end
    end

    module ClassMethods
      # Passes the record off to the class or classes specified and allows them
      # to add errors based on more complex conditions.
      #
      #   class Person
      #     include ActiveModel::Validations
      #     validates_with MyValidator
      #   end
      #
      #   class MyValidator < ActiveModel::Validator
      #     def validate(record)
      #       if some_complex_logic
      #         record.errors.add :base, 'This record is invalid'
      #       end
      #     end
      #
      #     private
      #       def some_complex_logic
      #         # ...
      #       end
      #   end
      #
      # You may also pass it multiple classes, like so:
      #
      #   class Person
      #     include ActiveModel::Validations
      #     validates_with MyValidator, MyOtherValidator, on: :create
      #   end
      #
      # Configuration options:
      # * <tt>:on</tt> - Specifies the contexts where this validation is active.
      #   Runs in all validation contexts by default +nil+. You can pass a symbol
      #   or an array of symbols. (e.g. <tt>on: :create</tt> or
      #   <tt>on: :custom_validation_context</tt> or
      #   <tt>on: [:create, :custom_validation_context]</tt>)
      # * <tt>:if</tt> - Specifies a method, proc, or string to call to determine
      #   if the validation should occur (e.g. <tt>if: :allow_validation</tt>,
      #   or <tt>if: Proc.new { |user| user.signup_step > 2 }</tt>).
      #   The method, proc, or string should return or evaluate to a +true+ or
      #   +false+ value.
      # * <tt>:unless</tt> - Specifies a method, proc, or string to call to
      #   determine if the validation should not occur
      #   (e.g. <tt>unless: :skip_validation</tt>, or
      #   <tt>unless: Proc.new { |user| user.signup_step <= 2 }</tt>).
      #   The method, proc, or string should return or evaluate to a +true+ or
      #   +false+ value.
      # * <tt>:strict</tt> - Specifies whether validation should be strict.
      #   See <tt>ActiveModel::Validations#validates!</tt> for more information.
      #
      # If you pass any additional configuration options, they will be passed
      # to the class and available as +options+:
      #
      #   class Person
      #     include ActiveModel::Validations
      #     validates_with MyValidator, my_custom_key: 'my custom value'
      #   end
      #
      #   class MyValidator < ActiveModel::Validator
      #     def validate(record)
      #       options[:my_custom_key] # => "my custom value"
      #     end
      #   end
      def validates_with(*args, &block)
        options = args.extract_options!
        options[:class] = self

        args.each do |klass|
          validator = klass.new(options, &block)

          if validator.respond_to?(:attributes) && !validator.attributes.empty?
            validator.attributes.each do |attribute|
              _validators[attribute.to_sym] << validator
            end
          else
            _validators[nil] << validator
          end

          validate(validator, options)
        end
      end
    end

    # Passes the record off to the class or classes specified and allows them
    # to add errors based on more complex conditions.
    #
    #   class Person
    #     include ActiveModel::Validations
    #
    #     validate :instance_validations
    #
    #     def instance_validations
    #       validates_with MyValidator
    #     end
    #   end
    #
    # Please consult the class method documentation for more information on
    # creating your own validator.
    #
    # You may also pass it multiple classes, like so:
    #
    #   class Person
    #     include ActiveModel::Validations
    #
    #     validate :instance_validations, on: :create
    #
    #     def instance_validations
    #       validates_with MyValidator, MyOtherValidator
    #     end
    #   end
    #
    # Standard configuration options (<tt>:on</tt>, <tt>:if</tt> and
    # <tt>:unless</tt>), which are available on the class version of
    # +validates_with+, should instead be placed on the +validates+ method
    # as these are applied and tested in the callback.
    #
    # If you pass any additional configuration options, they will be passed
    # to the class and available as +options+, please refer to the
    # class version of this method for more information.
    def validates_with(*args, &block)
      options = args.extract_options!
      options[:class] = self.class

      args.each do |klass|
        validator = klass.new(options, &block)
        validator.validate(self)
      end
    end
  end
end

with_validation_test.rb

# frozen_string_literal: true

require "cases/helper"

require "models/topic"

class ValidatesWithTest < ActiveModel::TestCase
  def teardown
    Topic.clear_validators!
  end

  ERROR_MESSAGE = "Validation error from validator"
  OTHER_ERROR_MESSAGE = "Validation error from other validator"

  class ValidatorThatAddsErrors < ActiveModel::Validator
    def validate(record)
      record.errors.add(:base, message: ERROR_MESSAGE)
    end
  end

  class OtherValidatorThatAddsErrors < ActiveModel::Validator
    def validate(record)
      record.errors.add(:base, message: OTHER_ERROR_MESSAGE)
    end
  end

  class ValidatorThatDoesNotAddErrors < ActiveModel::Validator
    def validate(record)
    end
  end

  class ValidatorThatValidatesOptions < ActiveModel::Validator
    def validate(record)
      if options[:field] == :first_name
        record.errors.add(:base, message: ERROR_MESSAGE)
      end
    end
  end

  class ValidatorPerEachAttribute < ActiveModel::EachValidator
    def validate_each(record, attribute, value)
      record.errors.add(attribute, message: "Value is #{value}")
    end
  end

  class ValidatorCheckValidity < ActiveModel::EachValidator
    def check_validity!
      raise "boom!"
    end
  end

  test "validation with class that adds errors" do
    Topic.validates_with(ValidatorThatAddsErrors)
    topic = Topic.new
    assert topic.invalid?, "A class that adds errors causes the record to be invalid"
    assert_includes topic.errors[:base], ERROR_MESSAGE
  end

  test "with a class that returns valid" do
    Topic.validates_with(ValidatorThatDoesNotAddErrors)
    topic = Topic.new
    assert topic.valid?, "A class that does not add errors does not cause the record to be invalid"
  end

  test "with multiple classes" do
    Topic.validates_with(ValidatorThatAddsErrors, OtherValidatorThatAddsErrors)
    topic = Topic.new
    assert_predicate topic, :invalid?
    assert_includes topic.errors[:base], ERROR_MESSAGE
    assert_includes topic.errors[:base], OTHER_ERROR_MESSAGE
  end

  test "passes all configuration options to the validator class" do
    topic = Topic.new
    validator = Minitest::Mock.new
    validator.expect(:new, validator, [{ foo: :bar, if: :condition_is_true, class: Topic }])
    validator.expect(:validate, nil, [topic])
    validator.expect(:is_a?, false, [String]) # Call run by ActiveSupport::Callbacks::Callback.build

    Topic.validates_with(validator, if: :condition_is_true, foo: :bar)
    assert_predicate topic, :valid?
    validator.verify
  end

  test "validates_with with options" do
    Topic.validates_with(ValidatorThatValidatesOptions, field: :first_name)
    topic = Topic.new
    assert_predicate topic, :invalid?
    assert_includes topic.errors[:base], ERROR_MESSAGE
  end

  test "validates_with each validator" do
    Topic.validates_with(ValidatorPerEachAttribute, attributes: [:title, :content])
    topic = Topic.new title: "Title", content: "Content"
    assert_predicate topic, :invalid?
    assert_equal ["Value is Title"], topic.errors[:title]
    assert_equal ["Value is Content"], topic.errors[:content]
  end

  test "each validator checks validity" do
    assert_raise RuntimeError do
      Topic.validates_with(ValidatorCheckValidity, attributes: [:title])
    end
  end

  test "each validator expects attributes to be given" do
    assert_raise ArgumentError do
      Topic.validates_with(ValidatorPerEachAttribute)
    end
  end

  test "each validator skip nil values if :allow_nil is set to true" do
    Topic.validates_with(ValidatorPerEachAttribute, attributes: [:title, :content], allow_nil: true)
    topic = Topic.new content: ""
    assert_predicate topic, :invalid?
    assert_empty topic.errors[:title]
    assert_equal ["Value is "], topic.errors[:content]
  end

  test "each validator skip blank values if :allow_blank is set to true" do
    Topic.validates_with(ValidatorPerEachAttribute, attributes: [:title, :content], allow_blank: true)
    topic = Topic.new content: ""
    assert_predicate topic, :valid?
    assert_empty topic.errors[:title]
    assert_empty topic.errors[:content]
  end

  test "validates_with can validate with an instance method" do
    Topic.validates :title, with: :my_validation

    topic = Topic.new title: "foo"
    assert_predicate topic, :valid?
    assert_empty topic.errors[:title]

    topic = Topic.new
    assert_not_predicate topic, :valid?
    assert_equal ["is missing"], topic.errors[:title]
  end

  test "optionally pass in the attribute being validated when validating with an instance method" do
    Topic.validates :title, :content, with: :my_validation_with_arg

    topic = Topic.new title: "foo"
    assert_not_predicate topic, :valid?
    assert_empty topic.errors[:title]
    assert_equal ["is missing"], topic.errors[:content]
  end
end

yaml_encoder.rb

# frozen_string_literal: true

module ActiveModel
  class AttributeSet
    # Attempts to do more intelligent YAML dumping of an
    # ActiveModel::AttributeSet to reduce the size of the resulting string
    class YAMLEncoder # :nodoc:
      def initialize(default_types)
        @default_types = default_types
      end

      def encode(attribute_set, coder)
        coder["concise_attributes"] = attribute_set.each_value.map do |attr|
          if attr.type.equal?(default_types[attr.name])
            attr.with_type(nil)
          else
            attr
          end
        end
      end

      def decode(coder)
        if coder["attributes"]
          coder["attributes"]
        else
          attributes_hash = Hash[coder["concise_attributes"].map do |attr|
            if attr.type.nil?
              attr = attr.with_type(default_types[attr.name])
            end
            [attr.name, attr]
          end]
          AttributeSet.new(attributes_hash)
        end
      end

      private
        attr_reader :default_types
    end
  end
end