scoped_find.rb

ActiveRecord::SpawnMethods::VALID_FIND_OPTIONS << :allow_unscoped_find

ActiveRecord::Base.class_eval do
  def self.allow_unscoped_find(&block)
    if block
      temporarily_change_ivar("@allow_unscoped_find", true) do
        yield
      end
    else
      relation.allow_unscoped_find
    end
  end

  def self.allow_unscoped_find?
    @allow_unscoped_find
  end
end

ActiveRecord::SpawnMethods.class_eval do
  def apply_finder_options_with_scoped_find_check(options)
    result = apply_finder_options_without_scoped_find_check(options)
    if options[:allow_unscoped_find]
      result.instance_variable_set("@allow_unscoped_find", true)
    end
    result
  end
  alias_method_chain :apply_finder_options, :scoped_find_check

  def except_with_scoped_find_check(*args)
    except_without_scoped_find_check(*args).tap do |result|
      _copy_allow_unscoped_ivar(self, result)
    end
  end
  alias_method_chain :except, :scoped_find_check

  def merge_with_scoped_find_check(relation)
    merge_without_scoped_find_check(relation).tap do |result|
      _copy_allow_unscoped_ivar(relation, result)
    end
  end
  alias_method_chain :merge, :scoped_find_check

  def only_with_scoped_find_check(*args)
    only_without_scoped_find_check(*args).tap do |result|
      _copy_allow_unscoped_ivar(self, result)
    end
  end
  alias_method_chain :only, :scoped_find_check

  def _copy_allow_unscoped_ivar(from, to)
    if from.instance_variable_get("@allow_unscoped_find")
      to.instance_variable_set("@allow_unscoped_find", true)
    end
  end
end

ActiveRecord::Relation.class_eval do
  attr_accessor :allow_unscoped_find

  def allow_unscoped_find
    relation = clone
    relation.allow_unscoped_find = true
    relation
  end

  def to_a_with_scoped_find_check
    sql = arel.to_sql
    unless _has_valid_conditions?(sql)
      raise RuntimeError, "#finds must be scoped on #{@klass.to_s}"
    end
    to_a_without_scoped_find_check
  end
  alias_method_chain :to_a, :scoped_find_check

  def _has_valid_conditions?(sql)
    @allow_unscoped_find || @klass.allow_unscoped_find? || _whitelisted_models.include?(@klass.to_s) || _valid_string_conditions?(sql) || false
  end

  def _valid_string_conditions?(conditions)
    conditions =~ /_id"? (=|IN|IS)/ || conditions =~ /"?\w+"?\."?id"? (=|IN)/
  end

  def _whitelisted_models
    [
      "Merchant",
    ]
  end
end