incoherent_validation_with_nested_attributes_for_belongs_to_association.rb

# frozen_string_literal: true

begin
  require "bundler/inline"
rescue LoadError => e
  $stderr.puts "Bundler version 1.10 or later is required. Please update your Bundler"
  raise e
end

gemfile(true) do
  source "https://rubygems.org"

  git_source(:github) { |repo| "https://github.com/#{repo}.git" }

  # Activate the gem you are reporting the issue against.
  gem "activerecord", "5.2.3"
  gem "sqlite3", "~> 1.3.6"
end

require "active_record"
require "minitest/autorun"
require "logger"

# Ensure backward compatibility with Minitest 4
Minitest::Test = MiniTest::Unit::TestCase unless defined?(Minitest::Test)

# This connection will do for database-independent bug reports.
ActiveRecord::Base.establish_connection(adapter: "sqlite3", database: ":memory:")
ActiveRecord::Base.logger = Logger.new(STDOUT)

ActiveRecord::Schema.define do
  create_table :people, force: true do |t|
    t.string :name
  end

  create_table :matriculations, force: :true do |t|
    t.bigint :person_id
  end
end

class Matriculation < ActiveRecord::Base
  belongs_to :person

  accepts_nested_attributes_for :person

  validate :fake_validation_with_return_false

  def fake_validation_with_return_false
    errors.add(:base, 'Fake error') if person.present? && false # Validation always returning false, but the detail is the use of object person.
  end
end

class Person < ActiveRecord::Base
  has_many :matriculations
  validates :name, presence: true
end

class BugTest < Minitest::Test
  def test_case
    person = Person.create!(name: 'Jhon')
    Matriculation.create!(person: person)

    person.name = nil
    person.save! validate: false # In this moment the object person is invalid. But matriculation isn't.

    matriculation = Matriculation.first

    assert_equal true, matriculation.valid? # First call
    assert_equal false, matriculation.valid? # Second call, return changed??? What?
    assert_equal [:"person.name"], matriculation.errors.keys
  end
end