Revert "Properly interpolate i18n keys in modules [#5572 state:resolved]"

This breaks #6448, you should use :"module/class" as key for namespacing
[#6448 state:committed]

This reverts commit 8d30193b08.

activemodel/lib/active_model/errors.rb

@@ -295,8 +295,8 @@ module ActiveModel
       type = options.delete(:message) if options[:message].is_a?(Symbol)
 
       defaults = @base.class.lookup_ancestors.map do |klass|
-        [ :"#{@base.class.i18n_scope}.errors.models.#{klass.model_name.i18n_key}.attributes.#{attribute}.#{type}",
-          :"#{@base.class.i18n_scope}.errors.models.#{klass.model_name.i18n_key}.#{type}" ]
+        [ :"#{@base.class.i18n_scope}.errors.models.#{klass.model_name.underscore}.attributes.#{attribute}.#{type}",
+          :"#{@base.class.i18n_scope}.errors.models.#{klass.model_name.underscore}.#{type}" ]
       end
 
       defaults << options.delete(:message)

activemodel/lib/active_model/naming.rb

@@ -4,7 +4,7 @@ require 'active_support/core_ext/module/introspection'
 
 module ActiveModel
   class Name < String
-    attr_reader :singular, :plural, :element, :collection, :partial_path, :route_key, :param_key, :i18n_key
+    attr_reader :singular, :plural, :element, :collection, :partial_path, :route_key, :param_key
     alias_method :cache_key, :collection
 
     def initialize(klass, namespace = nil)
@@ -20,7 +20,6 @@ module ActiveModel
       @partial_path = "#{@collection}/#{@element}".freeze
       @param_key = (namespace ? _singularize(@unnamespaced) : @singular).freeze
       @route_key = (namespace ? ActiveSupport::Inflector.pluralize(@param_key) : @plural).freeze
-      @i18n_key = _singularize(self, '.').to_sym
     end
 
     # Transform the model name into a more humane format, using I18n. By default,
@@ -34,7 +33,7 @@ module ActiveModel
                            @klass.respond_to?(:i18n_scope)
 
       defaults = @klass.lookup_ancestors.map do |klass|
-        klass.model_name.i18n_key
+        klass.model_name.underscore.to_sym
       end
 
       defaults << options[:default] if options[:default]
@@ -45,10 +44,9 @@ module ActiveModel
     end
 
     private
-
-    def _singularize(string, replacement='_')
-      ActiveSupport::Inflector.underscore(string).tr('/', replacement)
-    end
+      def _singularize(str)
+        ActiveSupport::Inflector.underscore(str).tr('/', '_')
+      end
   end
 
   # == Active Model Naming
@@ -64,9 +62,6 @@ module ActiveModel
   #   BookCover.model_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.

activemodel/lib/active_model/translation.rb

@@ -44,7 +44,7 @@ module ActiveModel
     # Specify +options+ with additional translating options.
     def human_attribute_name(attribute, options = {})
       defaults = lookup_ancestors.map do |klass|
-        :"#{self.i18n_scope}.attributes.#{klass.model_name.i18n_key}.#{attribute}"
+        :"#{self.i18n_scope}.attributes.#{klass.model_name.underscore}.#{attribute}"
       end
 
       defaults << :"attributes.#{attribute}"

activemodel/test/cases/validations/i18n_validation_test.rb

@@ -55,14 +55,6 @@ class I18nValidationTest < ActiveModel::TestCase
     assert_equal ["Person's name not found"], @person.errors.full_messages
   end
 
-  def test_errors_full_messages_translates_human_attribute_name_for_model_in_module_attributes
-    I18n.backend.store_translations('en', :activemodel => {:attributes => {:person_module => {:person => {:name => "Person in Module's name"}}}})
-    person = PersonModule::Person.new
-    person.errors.add(:name, 'not found')
-    PersonModule::Person.expects(:human_attribute_name).with(:name, :default => 'Name').returns("Person in Module's name")
-    assert_equal ["Person in Module's name not found"], person.errors.full_messages
-  end
-
   def test_errors_full_messages_uses_format
     I18n.backend.store_translations('en', :errors => {:format => "Field %{attribute} %{message}"})
     @person.errors.add('name', 'empty')
@@ -371,15 +363,4 @@ class I18nValidationTest < ActiveModel::TestCase
     assert_equal ["I am a custom error"], @person.errors[:title]
   end
 
-  def test_model_with_module_i18n_scope
-      I18n.backend.store_translations 'en', :activemodel => {:errors => {:models => {:person_module => {:person => {:blank => 'generic blank'}}}}}
-      PersonModule::Person.validates_presence_of :title
-      person = PersonModule::Person.new
-      person.valid?
-      assert_equal ['generic blank'], person.errors[:title]
-
-      I18n.backend.store_translations 'en', :activemodel => {:errors => {:models => {:person_module => {:person => {:attributes => {:title => {:blank => 'title cannot be blank'}}}}}}}
-      person.valid?
-      assert_equal ['title cannot be blank'], person.errors[:title]
-  end
 end

activemodel/test/models/person.rb

@@ -15,8 +15,3 @@ end
 
 class Child < Person
 end
-
-module PersonModule
-  class Person < ::Person
-  end
-end