Add I18n translations to ActiveModel and move more AR specific parts to ActiveRecord::Validations

14 files changed, 1277 insertions, 491 deletions

diff --git a/activemodel/lib/active_model.rb b/activemodel/lib/active_model.rb
index 1a330ef4ae..7f943b60ce 100644
--- a/activemodel/lib/active_model.rb
+++ b/activemodel/lib/active_model.rb
@@ -41,3 +41,5 @@ module ActiveModel
   autoload :StateMachine, 'active_model/state_machine'
   autoload :ValidationsRepairHelper, 'active_model/validations_repair_helper'
 end
+
+I18n.load_path << File.dirname(__FILE__) + '/active_model/locale/en.yml'
diff --git a/activemodel/lib/active_model/errors.rb b/activemodel/lib/active_model/errors.rb
index b9541ca3be..c2bde29895 100644
--- a/activemodel/lib/active_model/errors.rb
+++ b/activemodel/lib/active_model/errors.rb
@@ -2,15 +2,6 @@ module ActiveModel
   class Errors < Hash
     include DeprecatedErrorMethods
 
-    class << self
-      def default_error_messages
-        message = "Errors.default_error_messages has been deprecated. Please use I18n.translate('activerecord.errors.messages')."
-        ActiveSupport::Deprecation.warn(message)
-
-        I18n.translate 'activerecord.errors.messages'
-      end
-    end
-
     def initialize(base)
       @base = base
       super()
@@ -74,7 +65,7 @@ module ActiveModel
     # Will add an error message to each of the attributes in +attributes+ that is empty.
     def add_on_empty(attributes, custom_message = nil)
       [attributes].flatten.each do |attribute|
-        value = @base.respond_to?(attribute.to_s) ? @base.send(attribute.to_s) : @base[attribute.to_s]
+        value = @base.get_attribute_value(attribute)
         is_empty = value.respond_to?(:empty?) ? value.empty? : false
         add(attribute, :empty, :default => custom_message) unless !value.nil? && !is_empty
       end
@@ -83,14 +74,14 @@ module ActiveModel
     # Will add an error message to each of the attributes in +attributes+ that is blank (using Object#blank?).
     def add_on_blank(attributes, custom_message = nil)
       [attributes].flatten.each do |attribute|
-        value = @base.respond_to?(attribute.to_sym) ? @base.send(attribute.to_sym) : @base[attribute.to_sym]
+        value = @base.get_attribute_value(attribute)
         add(attribute, :blank, :default => custom_message) if value.blank?
       end
     end
 
     # Returns all the full error messages in an array.
     #
-    #   class Company < ActiveRecord::Base
+    #   class Company
     #     validates_presence_of :name, :address, :email
     #     validates_length_of :name, :in => 5..30
     #   end
@@ -107,13 +98,8 @@ module ActiveModel
         if attribute == :base
           messages.each {|m| full_messages << m }
         else
-          if @base.class.respond_to?(:human_attribute_name)
-            attr_name = @base.class.human_attribute_name(attribute.to_s)
-          else
-            attr_name = attribute.to_s.humanize
-          end
-
-          prefix = attr_name + I18n.t('activerecord.errors.format.separator', :default => ' ')
+          attr_name = attribute.to_s.humanize
+          prefix = attr_name + I18n.t('activemodel.errors.format.separator', :default => ' ')
           messages.each do |m|
             full_messages <<  "#{prefix}#{m}"
           end
@@ -123,10 +109,10 @@ module ActiveModel
       full_messages
     end
 
-    # Translates an error message in it's default scope (<tt>activerecord.errrors.messages</tt>).
+    # Translates an error message in it's default scope (<tt>activemodel.errrors.messages</tt>).
     # Error messages are first looked up in <tt>models.MODEL.attributes.ATTRIBUTE.MESSAGE</tt>, if it's not there, 
     # it's looked up in <tt>models.MODEL.MESSAGE</tt> and if that is not there it returns the translation of the 
-    # default message (e.g. <tt>activerecord.errors.messages.MESSAGE</tt>). The translated model name, 
+    # 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 inheritence in your models, it will check all the inherited models too, but only if the model itself
@@ -134,36 +120,38 @@ module ActiveModel
     # error +message+ for the <tt>title</tt> +attribute+, it looks for these translations:
     # 
     # <ol>
-    # <li><tt>activerecord.errors.models.admin.attributes.title.blank</tt></li>
-    # <li><tt>activerecord.errors.models.admin.blank</tt></li>
-    # <li><tt>activerecord.errors.models.user.attributes.title.blank</tt></li>
-    # <li><tt>activerecord.errors.models.user.blank</tt></li>
-    # <li><tt>activerecord.errors.messages.blank</tt></li>
-    # <li>any default you provided through the +options+ hash (in the activerecord.errors scope)</li>
+    # <li><tt>activemodel.errors.models.admin.attributes.title.blank</tt></li>
+    # <li><tt>activemodel.errors.models.admin.blank</tt></li>
+    # <li><tt>activemodel.errors.models.user.attributes.title.blank</tt></li>
+    # <li><tt>activemodel.errors.models.user.blank</tt></li>
+    # <li><tt>activemodel.errors.messages.blank</tt></li>
+    # <li>any default you provided through the +options+ hash (in the activemodel.errors scope)</li>
     # </ol>
     def generate_message(attribute, message = :invalid, options = {})
       message, options[:default] = options[:default], message if options[:default].is_a?(Symbol)
 
-      defaults = @base.class.self_and_descendants_from_active_record.map do |klass|
+      klass_ancestors = [@base.class]
+      klass_ancestors += @base.class.ancestors.reject {|x| x.is_a?(Module)}
+
+      defaults = klass_ancestors.map do |klass|
         [ :"models.#{klass.name.underscore}.attributes.#{attribute}.#{message}", 
           :"models.#{klass.name.underscore}.#{message}" ]
       end
-      
+
       defaults << options.delete(:default)
       defaults = defaults.compact.flatten << :"messages.#{message}"
 
       key = defaults.shift
-      value = @base.respond_to?(attribute) ? @base.send(attribute) : nil
+      value = @base.get_attribute_value(attribute)
 
       options = { :default => defaults,
-        :model => @base.class.human_name,
-        :attribute => @base.class.human_attribute_name(attribute.to_s),
+        :model => @base.class.name.humanize,
+        :attribute => attribute.to_s.humanize,
         :value => value,
-        :scope => [:activerecord, :errors]
+        :scope => [:activemodel, :errors]
       }.merge(options)
 
       I18n.translate(key, options)
     end
-
   end
 end
\ No newline at end of file
diff --git a/activemodel/lib/active_model/locale/en.yml b/activemodel/lib/active_model/locale/en.yml
new file mode 100644
index 0000000000..0c2cf9ea33
--- /dev/null
+++ b/activemodel/lib/active_model/locale/en.yml
@@ -0,0 +1,24 @@
+en:
+  activemodel:
+    errors:
+      # The values :model, :attribute and :value are always available for interpolation
+      # The value :count is available when applicable. Can be used for pluralization.
+      messages:
+        inclusion: "is not included in the list"
+        exclusion: "is reserved"
+        invalid: "is invalid"
+        confirmation: "doesn't match confirmation"
+        accepted: "must be accepted"
+        empty: "can't be empty"
+        blank: "can't be blank"
+        too_long: "is too long (maximum is {{count}} characters)"
+        too_short: "is too short (minimum is {{count}} characters)"
+        wrong_length: "is the wrong length (should be {{count}} characters)"
+        not_a_number: "is not a number"
+        greater_than: "must be greater than {{count}}"
+        greater_than_or_equal_to: "must be greater than or equal to {{count}}"
+        equal_to: "must be equal to {{count}}"
+        less_than: "must be less than {{count}}"
+        less_than_or_equal_to: "must be less than or equal to {{count}}"
+        odd: "must be odd"
+        even: "must be even"
diff --git a/activemodel/lib/active_model/validations.rb b/activemodel/lib/active_model/validations.rb
index 3ea17381c9..c0bbad0396 100644
--- a/activemodel/lib/active_model/validations.rb
+++ b/activemodel/lib/active_model/validations.rb
@@ -5,7 +5,7 @@ module ActiveModel
     def self.included(base) # :nodoc:
       base.extend(ClassMethods)
       base.__send__(:include, ActiveSupport::Callbacks)
-      base.define_callbacks :validate, :validate_on_create, :validate_on_update
+      base.define_callbacks :validate
     end
 
     module ClassMethods
@@ -64,7 +64,7 @@ module ActiveModel
         # Declare the validation.
         send(validation_method(options[:on] || :save), options) do |record|
           attrs.each do |attr|
-            value = record.send(attr)
+            value = record.get_attribute_value(attr)
             next if (value.nil? && options[:allow_nil]) || (value.blank? && options[:allow_blank])
             yield record, attr, value
           end
@@ -72,13 +72,14 @@ module ActiveModel
       end
 
       private
-        def validation_method(on)
-          case on
-            when :save   then :validate
-            when :create then :validate_on_create
-            when :update then :validate_on_update
-          end
+
+      def validation_method(on)
+        case on
+        when :save   then :validate
+        when :create then :validate_on_create
+        when :update then :validate_on_update
         end
+      end
     end
 
     # Returns the Errors object that holds all information about attribute error messages.
@@ -91,27 +92,7 @@ module ActiveModel
       errors.clear
 
       run_callbacks(:validate)
-      
-      if respond_to?(:validate)
-        # ActiveSupport::Deprecation.warn "Base#validate has been deprecated, please use Base.validate :method instead"
-        validate
-      end
-
-      if new_record?
-        run_callbacks(:validate_on_create)
-
-        if respond_to?(:validate_on_create)
-          # ActiveSupport::Deprecation.warn "Base#validate_on_create has been deprecated, please use Base.validate_on_create :method instead"
-          validate_on_create
-        end
-      else
-        run_callbacks(:validate_on_update)
-
-        if respond_to?(:validate_on_update)
-          # ActiveSupport::Deprecation.warn "Base#validate_on_update has been deprecated, please use Base.validate_on_update :method instead"
-          validate_on_update
-        end
-      end
+      validate if respond_to?(:validate)
 
       errors.empty?
     end
@@ -121,19 +102,15 @@ module ActiveModel
       !valid?
     end
 
+    def get_attribute_value(attribute)
+      respond_to?(attribute.to_sym) ? send(attribute.to_sym) : instance_variable_get(:"@#{attribute}")
+    end
+
     protected
     
     # Overwrite this method for validation checks on all saves and use <tt>Errors.add(field, msg)</tt> for invalid attributes.
     def validate
     end
-
-    # Overwrite this method for validation checks used only on creation.
-    def validate_on_create
-    end
-
-    # Overwrite this method for validation checks used only on updates.
-    def validate_on_update
-    end
   end
 end
 
diff --git a/activemodel/lib/active_model/validations/length.rb b/activemodel/lib/active_model/validations/length.rb
index f6bb1f6d70..9736595990 100644
--- a/activemodel/lib/active_model/validations/length.rb
+++ b/activemodel/lib/active_model/validations/length.rb
@@ -48,12 +48,12 @@ module ActiveModel
         # Ensure that one and only one range option is specified.
         range_options = ALL_RANGE_OPTIONS & options.keys
         case range_options.size
-          when 0
-            raise ArgumentError, 'Range unspecified.  Specify the :within, :maximum, :minimum, or :is option.'
-          when 1
-            # Valid number of options; do nothing.
-          else
-            raise ArgumentError, 'Too many range options specified.  Choose only one.'
+        when 0
+          raise ArgumentError, 'Range unspecified.  Specify the :within, :maximum, :minimum, or :is option.'
+        when 1
+          # Valid number of options; do nothing.
+        else
+          raise ArgumentError, 'Too many range options specified.  Choose only one.'
         end
 
         # Get range option and value.
diff --git a/activemodel/lib/active_model/validations/numericality.rb b/activemodel/lib/active_model/validations/numericality.rb
index d8e3470304..99035b8af8 100644
--- a/activemodel/lib/active_model/validations/numericality.rb
+++ b/activemodel/lib/active_model/validations/numericality.rb
@@ -35,7 +35,6 @@ module ActiveModel
         configuration = { :on => :save, :only_integer => false, :allow_nil => false }
         configuration.update(attr_names.extract_options!)
 
-
         numericality_options = ALL_NUMERICALITY_CHECKS.keys & configuration.keys
 
         (numericality_options - [ :odd, :even ]).each do |option|
@@ -43,7 +42,13 @@ module ActiveModel
         end
 
         validates_each(attr_names,configuration) do |record, attr_name, value|
-          raw_value = record.send("#{attr_name}_before_type_cast") || value
+          before_type_cast = "#{attr_name}_before_type_cast"
+
+          if record.respond_to?(before_type_cast.to_sym)
+            raw_value = record.send("#{attr_name}_before_type_cast") || value
+          else
+            raw_value = value
+          end
 
           next if configuration[:allow_nil] and raw_value.nil?
 
@@ -64,14 +69,14 @@ module ActiveModel
 
           numericality_options.each do |option|
             case option
-              when :odd, :even
-                unless raw_value.to_i.method(ALL_NUMERICALITY_CHECKS[option])[]
-                  record.errors.add(attr_name, option, :value => raw_value, :default => configuration[:message]) 
-                end
-              else
-                unless raw_value.method(ALL_NUMERICALITY_CHECKS[option])[configuration[option]]
-                  record.errors.add(attr_name, option, :default => configuration[:message], :value => raw_value, :count => configuration[option])
-                end
+            when :odd, :even
+              unless raw_value.to_i.method(ALL_NUMERICALITY_CHECKS[option])[]
+                record.errors.add(attr_name, option, :value => raw_value, :default => configuration[:message]) 
+              end
+            else
+              unless raw_value.method(ALL_NUMERICALITY_CHECKS[option])[configuration[option]]
+                record.errors.add(attr_name, option, :default => configuration[:message], :value => raw_value, :count => configuration[option])
+              end
             end
           end
         end
diff --git a/activemodel/test/cases/validations/i18n_generate_message_validation_test.rb b/activemodel/test/cases/validations/i18n_generate_message_validation_test.rb
index 871c69d06d..37bba5e95e 100644
--- a/activemodel/test/cases/validations/i18n_generate_message_validation_test.rb
+++ b/activemodel/test/cases/validations/i18n_generate_message_validation_test.rb
@@ -1,13 +1,19 @@
 require "cases/helper"
-require 'models/topic'
-require 'models/reply'
+require 'cases/tests_database'
+
+require 'models/person'
 
 class I18nGenerateMessageValidationTest < Test::Unit::TestCase
   def setup
-    reset_callbacks Topic
-    @topic = Topic.new
+    reset_callbacks Person
+    @person = Person.new
+
+    @old_load_path, @old_backend = I18n.load_path, I18n.backend
+    I18n.load_path.clear
+    I18n.backend = I18n::Backend::Simple.new
+
     I18n.backend.store_translations :'en', {
-      :activerecord => {
+      :activemodel => {
         :errors => {
           :messages => {
             :inclusion => "is not included in the list",
@@ -34,141 +40,143 @@ class I18nGenerateMessageValidationTest < Test::Unit::TestCase
     }
   end
 
+  def teardown
+    I18n.load_path.replace @old_load_path
+    I18n.backend = @old_backend
+  end
+
   def reset_callbacks(*models)
     models.each do |model|
       model.instance_variable_set("@validate_callbacks", ActiveSupport::Callbacks::CallbackChain.new)
-      model.instance_variable_set("@validate_on_create_callbacks", ActiveSupport::Callbacks::CallbackChain.new)
-      model.instance_variable_set("@validate_on_update_callbacks", ActiveSupport::Callbacks::CallbackChain.new)
     end
   end
 
   # validates_inclusion_of: generate_message(attr_name, :inclusion, :default => configuration[:message], :value => value)
   def test_generate_message_inclusion_with_default_message
-    assert_equal 'is not included in the list', @topic.errors.generate_message(:title, :inclusion, :default => nil, :value => 'title')
+    assert_equal 'is not included in the list', @person.errors.generate_message(:title, :inclusion, :default => nil, :value => 'title')
   end
 
   def test_generate_message_inclusion_with_custom_message
-    assert_equal 'custom message title', @topic.errors.generate_message(:title, :inclusion, :default => 'custom message {{value}}', :value => 'title')
+    assert_equal 'custom message title', @person.errors.generate_message(:title, :inclusion, :default => 'custom message {{value}}', :value => 'title')
   end
 
   # validates_exclusion_of: generate_message(attr_name, :exclusion, :default => configuration[:message], :value => value)
   def test_generate_message_exclusion_with_default_message
-    assert_equal 'is reserved', @topic.errors.generate_message(:title, :exclusion, :default => nil, :value => 'title')
+    assert_equal 'is reserved', @person.errors.generate_message(:title, :exclusion, :default => nil, :value => 'title')
   end
 
   def test_generate_message_exclusion_with_custom_message
-    assert_equal 'custom message title', @topic.errors.generate_message(:title, :exclusion, :default => 'custom message {{value}}', :value => 'title')
+    assert_equal 'custom message title', @person.errors.generate_message(:title, :exclusion, :default => 'custom message {{value}}', :value => 'title')
   end
 
   # validates_associated: generate_message(attr_name, :invalid, :default => configuration[:message], :value => value)
   # validates_format_of:  generate_message(attr_name, :invalid, :default => configuration[:message], :value => value)
   def test_generate_message_invalid_with_default_message
-    assert_equal 'is invalid', @topic.errors.generate_message(:title, :invalid, :default => nil, :value => 'title')
+    assert_equal 'is invalid', @person.errors.generate_message(:title, :invalid, :default => nil, :value => 'title')
   end
 
   def test_generate_message_invalid_with_custom_message
-    assert_equal 'custom message title', @topic.errors.generate_message(:title, :invalid, :default => 'custom message {{value}}', :value => 'title')
+    assert_equal 'custom message title', @person.errors.generate_message(:title, :invalid, :default => 'custom message {{value}}', :value => 'title')
   end
 
   # validates_confirmation_of: generate_message(attr_name, :confirmation, :default => configuration[:message])
   def test_generate_message_confirmation_with_default_message
-    assert_equal "doesn't match confirmation", @topic.errors.generate_message(:title, :confirmation, :default => nil)
+    assert_equal "doesn't match confirmation", @person.errors.generate_message(:title, :confirmation, :default => nil)
   end
 
   def test_generate_message_confirmation_with_custom_message
-    assert_equal 'custom message', @topic.errors.generate_message(:title, :confirmation, :default => 'custom message')
+    assert_equal 'custom message', @person.errors.generate_message(:title, :confirmation, :default => 'custom message')
   end
 
   # validates_acceptance_of: generate_message(attr_name, :accepted, :default => configuration[:message])
   def test_generate_message_accepted_with_default_message
-    assert_equal "must be accepted", @topic.errors.generate_message(:title, :accepted, :default => nil)
+    assert_equal "must be accepted", @person.errors.generate_message(:title, :accepted, :default => nil)
   end
 
   def test_generate_message_accepted_with_custom_message
-    assert_equal 'custom message', @topic.errors.generate_message(:title, :accepted, :default => 'custom message')
+    assert_equal 'custom message', @person.errors.generate_message(:title, :accepted, :default => 'custom message')
   end
 
   # add_on_empty: generate_message(attr, :empty, :default => custom_message)
   def test_generate_message_empty_with_default_message
-    assert_equal "can't be empty", @topic.errors.generate_message(:title, :empty, :default => nil)
+    assert_equal "can't be empty", @person.errors.generate_message(:title, :empty, :default => nil)
   end
 
   def test_generate_message_empty_with_custom_message
-    assert_equal 'custom message', @topic.errors.generate_message(:title, :empty, :default => 'custom message')
+    assert_equal 'custom message', @person.errors.generate_message(:title, :empty, :default => 'custom message')
   end
 
   # add_on_blank: generate_message(attr, :blank, :default => custom_message)
   def test_generate_message_blank_with_default_message
-    assert_equal "can't be blank", @topic.errors.generate_message(:title, :blank, :default => nil)
+    assert_equal "can't be blank", @person.errors.generate_message(:title, :blank, :default => nil)
   end
 
   def test_generate_message_blank_with_custom_message
-    assert_equal 'custom message', @topic.errors.generate_message(:title, :blank, :default => 'custom message')
+    assert_equal 'custom message', @person.errors.generate_message(:title, :blank, :default => 'custom message')
   end
 
   # validates_length_of: generate_message(attr, :too_long, :default => options[:too_long], :count => option_value.end)
   def test_generate_message_too_long_with_default_message
-    assert_equal "is too long (maximum is 10 characters)", @topic.errors.generate_message(:title, :too_long, :default => nil, :count => 10)
+    assert_equal "is too long (maximum is 10 characters)", @person.errors.generate_message(:title, :too_long, :default => nil, :count => 10)
   end
 
   def test_generate_message_too_long_with_custom_message
-    assert_equal 'custom message 10', @topic.errors.generate_message(:title, :too_long, :default => 'custom message {{count}}', :count => 10)
+    assert_equal 'custom message 10', @person.errors.generate_message(:title, :too_long, :default => 'custom message {{count}}', :count => 10)
   end
 
   # validates_length_of: generate_message(attr, :too_short, :default => options[:too_short], :count => option_value.begin)
   def test_generate_message_too_short_with_default_message
-    assert_equal "is too short (minimum is 10 characters)", @topic.errors.generate_message(:title, :too_short, :default => nil, :count => 10)
+    assert_equal "is too short (minimum is 10 characters)", @person.errors.generate_message(:title, :too_short, :default => nil, :count => 10)
   end
 
   def test_generate_message_too_short_with_custom_message
-    assert_equal 'custom message 10', @topic.errors.generate_message(:title, :too_short, :default => 'custom message {{count}}', :count => 10)
+    assert_equal 'custom message 10', @person.errors.generate_message(:title, :too_short, :default => 'custom message {{count}}', :count => 10)
   end
 
   # validates_length_of: generate_message(attr, key, :default => custom_message, :count => option_value)
   def test_generate_message_wrong_length_with_default_message
-    assert_equal "is the wrong length (should be 10 characters)", @topic.errors.generate_message(:title, :wrong_length, :default => nil, :count => 10)
+    assert_equal "is the wrong length (should be 10 characters)", @person.errors.generate_message(:title, :wrong_length, :default => nil, :count => 10)
   end
 
   def test_generate_message_wrong_length_with_custom_message
-    assert_equal 'custom message 10', @topic.errors.generate_message(:title, :wrong_length, :default => 'custom message {{count}}', :count => 10)
+    assert_equal 'custom message 10', @person.errors.generate_message(:title, :wrong_length, :default => 'custom message {{count}}', :count => 10)
   end
 
   # validates_numericality_of: generate_message(attr_name, :not_a_number, :value => raw_value, :default => configuration[:message])
   def test_generate_message_not_a_number_with_default_message
-    assert_equal "is not a number", @topic.errors.generate_message(:title, :not_a_number, :default => nil, :value => 'title')
+    assert_equal "is not a number", @person.errors.generate_message(:title, :not_a_number, :default => nil, :value => 'title')
   end
 
   def test_generate_message_not_a_number_with_custom_message
-    assert_equal 'custom message title', @topic.errors.generate_message(:title, :not_a_number, :default => 'custom message {{value}}', :value => 'title')
+    assert_equal 'custom message title', @person.errors.generate_message(:title, :not_a_number, :default => 'custom message {{value}}', :value => 'title')
   end
 
   # validates_numericality_of: generate_message(attr_name, option, :value => raw_value, :default => configuration[:message])
   def test_generate_message_greater_than_with_default_message
-    assert_equal "must be greater than 10", @topic.errors.generate_message(:title, :greater_than, :default => nil, :value => 'title', :count => 10)
+    assert_equal "must be greater than 10", @person.errors.generate_message(:title, :greater_than, :default => nil, :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", @topic.errors.generate_message(:title, :greater_than_or_equal_to, :default => nil, :value => 'title', :count => 10)
+    assert_equal "must be greater than or equal to 10", @person.errors.generate_message(:title, :greater_than_or_equal_to, :default => nil, :value => 'title', :count => 10)
   end
 
   def test_generate_message_equal_to_with_default_message
-    assert_equal "must be equal to 10", @topic.errors.generate_message(:title, :equal_to, :default => nil, :value => 'title', :count => 10)
+    assert_equal "must be equal to 10", @person.errors.generate_message(:title, :equal_to, :default => nil, :value => 'title', :count => 10)
   end
 
   def test_generate_message_less_than_with_default_message
-    assert_equal "must be less than 10", @topic.errors.generate_message(:title, :less_than, :default => nil, :value => 'title', :count => 10)
+    assert_equal "must be less than 10", @person.errors.generate_message(:title, :less_than, :default => nil, :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", @topic.errors.generate_message(:title, :less_than_or_equal_to, :default => nil, :value => 'title', :count => 10)
+    assert_equal "must be less than or equal to 10", @person.errors.generate_message(:title, :less_than_or_equal_to, :default => nil, :value => 'title', :count => 10)
   end
 
   def test_generate_message_odd_with_default_message
-    assert_equal "must be odd", @topic.errors.generate_message(:title, :odd, :default => nil, :value => 'title', :count => 10)
+    assert_equal "must be odd", @person.errors.generate_message(:title, :odd, :default => nil, :value => 'title', :count => 10)
   end
 
   def test_generate_message_even_with_default_message
-    assert_equal "must be even", @topic.errors.generate_message(:title, :even, :default => nil, :value => 'title', :count => 10)
+    assert_equal "must be even", @person.errors.generate_message(:title, :even, :default => nil, :value => 'title', :count => 10)
   end
-
 end
diff --git a/activemodel/test/cases/validations/i18n_validation_test.rb b/activemodel/test/cases/validations/i18n_validation_test.rb
index 8eedf76d41..a1bb93b731 100644
--- a/activemodel/test/cases/validations/i18n_validation_test.rb
+++ b/activemodel/test/cases/validations/i18n_validation_test.rb
@@ -1,21 +1,24 @@
 require "cases/helper"
-require 'models/topic'
-require 'models/reply'
+require 'cases/tests_database'
+
+require 'models/person'
 
 class I18nValidationTest < ActiveModel::TestCase
   include ActiveModel::TestsDatabase
 
   def setup
-    reset_callbacks Topic
-    @topic = Topic.new
+    reset_callbacks Person
+
+    @person = Person.new
+
     @old_load_path, @old_backend = I18n.load_path, I18n.backend
     I18n.load_path.clear
     I18n.backend = I18n::Backend::Simple.new
-    I18n.backend.store_translations('en', :activerecord => {:errors => {:messages => {:custom => nil}}})
+    I18n.backend.store_translations('en', :activemodel => {:errors => {:messages => {:custom => nil}}})
   end
 
   def teardown
-    reset_callbacks Topic
+    reset_callbacks Person
     I18n.load_path.replace @old_load_path
     I18n.backend = @old_backend
   end
@@ -23,14 +26,6 @@ class I18nValidationTest < ActiveModel::TestCase
   def reset_callbacks(*models)
     models.each do |model|
       model.instance_variable_set("@validate_callbacks", ActiveSupport::Callbacks::CallbackChain.new)
-      model.instance_variable_set("@validate_on_create_callbacks", ActiveSupport::Callbacks::CallbackChain.new)
-      model.instance_variable_set("@validate_on_update_callbacks", ActiveSupport::Callbacks::CallbackChain.new)
-    end
-  end
-
-  def test_default_error_messages_is_deprecated
-    assert_deprecated('Errors.default_error_messages') do
-      ActiveModel::Errors.default_error_messages
     end
   end
 
@@ -60,613 +55,537 @@ class I18nValidationTest < ActiveModel::TestCase
     end
   end
 
-  # ActiveModel::Errors
-  def test_errors_generate_message_translates_custom_model_attribute_key
-
-    I18n.expects(:translate).with(
-      :topic,
-      { :count => 1,
-        :default => ['Topic'],
-        :scope => [:activerecord, :models]
-      }
-    ).returns('Topic')
-
-    I18n.expects(:translate).with(
-      :"topic.title",
-      { :count => 1,
-        :default => ['Title'],
-        :scope => [:activerecord, :attributes]
-      }
-    ).returns('Title')
-
-    I18n.expects(:translate).with(
-      :"models.topic.attributes.title.invalid",
-      :value => nil,
-      :scope => [:activerecord, :errors],
-      :default => [
-        :"models.topic.invalid",
-        'default from class def error 1',
-        :"messages.invalid"],
-      :attribute => "Title",
-      :model => "Topic"
-    ).returns('default from class def error 1')
-
-    @topic.errors.generate_message :title, :invalid, :default => 'default from class def error 1'
-  end
-
-  def test_errors_generate_message_translates_custom_model_attribute_keys_with_sti
-
-    I18n.expects(:translate).with(
-      :reply,
-      { :count => 1,
-        :default => [:topic, 'Reply'],
-        :scope => [:activerecord, :models]
-      }
-    ).returns('Reply')
-
-    I18n.expects(:translate).with(
-      :"reply.title",
-      { :count => 1,
-        :default => [:'topic.title', 'Title'],
-        :scope => [:activerecord, :attributes]
-      }
-    ).returns('Title')
-
-    I18n.expects(:translate).with(
-      :"models.reply.attributes.title.invalid",
-      :value => nil,
-      :scope => [:activerecord, :errors],
-      :default => [
-        :"models.reply.invalid",
-        :"models.topic.attributes.title.invalid",
-        :"models.topic.invalid",
-        'default from class def',
-        :"messages.invalid"],
-      :model => 'Reply',
-      :attribute => 'Title'
-    ).returns("default from class def")
-
-    Reply.new.errors.generate_message :title, :invalid, :default => 'default from class def'
-
-  end
-
   def test_errors_add_on_empty_generates_message
-    @topic.errors.expects(:generate_message).with(:title, :empty, {:default => nil})
-    @topic.errors.add_on_empty :title
+    @person.errors.expects(:generate_message).with(:title, :empty, {:default => nil})
+    @person.errors.add_on_empty :title
   end
 
   def test_errors_add_on_empty_generates_message_with_custom_default_message
-    @topic.errors.expects(:generate_message).with(:title, :empty, {:default => 'custom'})
-    @topic.errors.add_on_empty :title, 'custom'
+    @person.errors.expects(:generate_message).with(:title, :empty, {:default => 'custom'})
+    @person.errors.add_on_empty :title, 'custom'
   end
 
   def test_errors_add_on_blank_generates_message
-    @topic.errors.expects(:generate_message).with(:title, :blank, {:default => nil})
-    @topic.errors.add_on_blank :title
+    @person.errors.expects(:generate_message).with(:title, :blank, {:default => nil})
+    @person.errors.add_on_blank :title
   end
 
   def test_errors_add_on_blank_generates_message_with_custom_default_message
-    @topic.errors.expects(:generate_message).with(:title, :blank, {:default => 'custom'})
-    @topic.errors.add_on_blank :title, 'custom'
-  end
-
-  def test_errors_full_messages_translates_human_attribute_name_for_model_attributes
-    @topic.errors.add('title', 'empty')
-    I18n.expects(:translate).with(:"topic.title", :default => ['Title'], :scope => [:activerecord, :attributes], :count => 1).returns('Title')
-    @topic.errors.full_messages :locale => 'en'
+    @person.errors.expects(:generate_message).with(:title, :blank, {:default => 'custom'})
+    @person.errors.add_on_blank :title, 'custom'
   end
 
   # ActiveRecord::Validations
   # validates_confirmation_of w/ mocha
   def test_validates_confirmation_of_generates_message
-    Topic.validates_confirmation_of :title
-    @topic.title_confirmation = 'foo'
-    @topic.errors.expects(:generate_message).with(:title, :confirmation, {:default => nil})
-    @topic.valid?
+    Person.validates_confirmation_of :title
+    @person.title_confirmation = 'foo'
+    @person.errors.expects(:generate_message).with(:title, :confirmation, {:default => nil})
+    @person.valid?
   end
 
   def test_validates_confirmation_of_generates_message_with_custom_default_message
-    Topic.validates_confirmation_of :title, :message => 'custom'
-    @topic.title_confirmation = 'foo'
-    @topic.errors.expects(:generate_message).with(:title, :confirmation, {:default => 'custom'})
-    @topic.valid?
+    Person.validates_confirmation_of :title, :message => 'custom'
+    @person.title_confirmation = 'foo'
+    @person.errors.expects(:generate_message).with(:title, :confirmation, {:default => 'custom'})
+    @person.valid?
   end
 
   # validates_acceptance_of w/ mocha
 
   def test_validates_acceptance_of_generates_message
-    Topic.validates_acceptance_of :title, :allow_nil => false
-    @topic.errors.expects(:generate_message).with(:title, :accepted, {:default => nil})
-    @topic.valid?
+    Person.validates_acceptance_of :title, :allow_nil => false
+    @person.errors.expects(:generate_message).with(:title, :accepted, {:default => nil})
+    @person.valid?
   end
 
   def test_validates_acceptance_of_generates_message_with_custom_default_message
-    Topic.validates_acceptance_of :title, :message => 'custom', :allow_nil => false
-    @topic.errors.expects(:generate_message).with(:title, :accepted, {:default => 'custom'})
-    @topic.valid?
+    Person.validates_acceptance_of :title, :message => 'custom', :allow_nil => false
+    @person.errors.expects(:generate_message).with(:title, :accepted, {:default => 'custom'})
+    @person.valid?
   end
 
   # validates_presence_of w/ mocha
 
   def test_validates_presence_of_generates_message
-    Topic.validates_presence_of :title
-    @topic.errors.expects(:generate_message).with(:title, :blank, {:default => nil})
-    @topic.valid?
+    Person.validates_presence_of :title
+    @person.errors.expects(:generate_message).with(:title, :blank, {:default => nil})
+    @person.valid?
   end
 
   def test_validates_presence_of_generates_message_with_custom_default_message
-    Topic.validates_presence_of :title, :message => 'custom'
-    @topic.errors.expects(:generate_message).with(:title, :blank, {:default => 'custom'})
-    @topic.valid?
+    Person.validates_presence_of :title, :message => 'custom'
+    @person.errors.expects(:generate_message).with(:title, :blank, {:default => 'custom'})
+    @person.valid?
   end
 
   def test_validates_length_of_within_generates_message_with_title_too_short
-    Topic.validates_length_of :title, :within => 3..5
-    @topic.errors.expects(:generate_message).with(:title, :too_short, {:count => 3, :default => nil})
-    @topic.valid?
+    Person.validates_length_of :title, :within => 3..5
+    @person.errors.expects(:generate_message).with(:title, :too_short, {:count => 3, :default => nil})
+    @person.valid?
   end
 
   def test_validates_length_of_within_generates_message_with_title_too_short_and_custom_default_message
-    Topic.validates_length_of :title, :within => 3..5, :too_short => 'custom'
-    @topic.errors.expects(:generate_message).with(:title, :too_short, {:count => 3, :default => 'custom'})
-    @topic.valid?
+    Person.validates_length_of :title, :within => 3..5, :too_short => 'custom'
+    @person.errors.expects(:generate_message).with(:title, :too_short, {:count => 3, :default => 'custom'})
+    @person.valid?
   end
 
   def test_validates_length_of_within_generates_message_with_title_too_long
-    Topic.validates_length_of :title, :within => 3..5
-    @topic.title = 'this title is too long'
-    @topic.errors.expects(:generate_message).with(:title, :too_long, {:count => 5, :default => nil})
-    @topic.valid?
+    Person.validates_length_of :title, :within => 3..5
+    @person.title = 'this title is too long'
+    @person.errors.expects(:generate_message).with(:title, :too_long, {:count => 5, :default => nil})
+    @person.valid?
   end
 
   def test_validates_length_of_within_generates_message_with_title_too_long_and_custom_default_message
-    Topic.validates_length_of :title, :within => 3..5, :too_long => 'custom'
-    @topic.title = 'this title is too long'
-    @topic.errors.expects(:generate_message).with(:title, :too_long, {:count => 5, :default => 'custom'})
-    @topic.valid?
+    Person.validates_length_of :title, :within => 3..5, :too_long => 'custom'
+    @person.title = 'this title is too long'
+    @person.errors.expects(:generate_message).with(:title, :too_long, {:count => 5, :default => 'custom'})
+    @person.valid?
   end
 
   # validates_length_of :within w/ mocha
 
   def test_validates_length_of_within_generates_message_with_title_too_short
-    Topic.validates_length_of :title, :within => 3..5
-    @topic.errors.expects(:generate_message).with(:title, :too_short, {:count => 3, :default => nil})
-    @topic.valid?
+    Person.validates_length_of :title, :within => 3..5
+    @person.errors.expects(:generate_message).with(:title, :too_short, {:count => 3, :default => nil})
+    @person.valid?
   end
 
   def test_validates_length_of_within_generates_message_with_title_too_short_and_custom_default_message
-    Topic.validates_length_of :title, :within => 3..5, :too_short => 'custom'
-    @topic.errors.expects(:generate_message).with(:title, :too_short, {:count => 3, :default => 'custom'})
-    @topic.valid?
+    Person.validates_length_of :title, :within => 3..5, :too_short => 'custom'
+    @person.errors.expects(:generate_message).with(:title, :too_short, {:count => 3, :default => 'custom'})
+    @person.valid?
   end
 
   def test_validates_length_of_within_generates_message_with_title_too_long
-    Topic.validates_length_of :title, :within => 3..5
-    @topic.title = 'this title is too long'
-    @topic.errors.expects(:generate_message).with(:title, :too_long, {:count => 5, :default => nil})
-    @topic.valid?
+    Person.validates_length_of :title, :within => 3..5
+    @person.title = 'this title is too long'
+    @person.errors.expects(:generate_message).with(:title, :too_long, {:count => 5, :default => nil})
+    @person.valid?
   end
 
   def test_validates_length_of_within_generates_message_with_title_too_long_and_custom_default_message
-    Topic.validates_length_of :title, :within => 3..5, :too_long => 'custom'
-    @topic.title = 'this title is too long'
-    @topic.errors.expects(:generate_message).with(:title, :too_long, {:count => 5, :default => 'custom'})
-    @topic.valid?
+    Person.validates_length_of :title, :within => 3..5, :too_long => 'custom'
+    @person.title = 'this title is too long'
+    @person.errors.expects(:generate_message).with(:title, :too_long, {:count => 5, :default => 'custom'})
+    @person.valid?
   end
 
   # validates_length_of :is w/ mocha
 
   def test_validates_length_of_is_generates_message
-    Topic.validates_length_of :title, :is => 5
-    @topic.errors.expects(:generate_message).with(:title, :wrong_length, {:count => 5, :default => nil})
-    @topic.valid?
+    Person.validates_length_of :title, :is => 5
+    @person.errors.expects(:generate_message).with(:title, :wrong_length, {:count => 5, :default => nil})
+    @person.valid?
   end
 
   def test_validates_length_of_is_generates_message_with_custom_default_message
-    Topic.validates_length_of :title, :is => 5, :message => 'custom'
-    @topic.errors.expects(:generate_message).with(:title, :wrong_length, {:count => 5, :default => 'custom'})
-    @topic.valid?
+    Person.validates_length_of :title, :is => 5, :message => 'custom'
+    @person.errors.expects(:generate_message).with(:title, :wrong_length, {:count => 5, :default => 'custom'})
+    @person.valid?
   end
 
   # validates_format_of w/ mocha
 
   def test_validates_format_of_generates_message
-    Topic.validates_format_of :title, :with => /^[1-9][0-9]*$/
-    @topic.title = '72x'
-    @topic.errors.expects(:generate_message).with(:title, :invalid, {:value => '72x', :default => nil})
-    @topic.valid?
+    Person.validates_format_of :title, :with => /^[1-9][0-9]*$/
+    @person.title = '72x'
+    @person.errors.expects(:generate_message).with(:title, :invalid, {:value => '72x', :default => nil})
+    @person.valid?
   end
 
   def test_validates_format_of_generates_message_with_custom_default_message
-    Topic.validates_format_of :title, :with => /^[1-9][0-9]*$/, :message => 'custom'
-    @topic.title = '72x'
-    @topic.errors.expects(:generate_message).with(:title, :invalid, {:value => '72x', :default => 'custom'})
-    @topic.valid?
+    Person.validates_format_of :title, :with => /^[1-9][0-9]*$/, :message => 'custom'
+    @person.title = '72x'
+    @person.errors.expects(:generate_message).with(:title, :invalid, {:value => '72x', :default => 'custom'})
+    @person.valid?
   end
 
   # validates_inclusion_of w/ mocha
 
   def test_validates_inclusion_of_generates_message
-    Topic.validates_inclusion_of :title, :in => %w(a b c)
-    @topic.title = 'z'
-    @topic.errors.expects(:generate_message).with(:title, :inclusion, {:value => 'z', :default => nil})
-    @topic.valid?
+    Person.validates_inclusion_of :title, :in => %w(a b c)
+    @person.title = 'z'
+    @person.errors.expects(:generate_message).with(:title, :inclusion, {:value => 'z', :default => nil})
+    @person.valid?
   end
 
   def test_validates_inclusion_of_generates_message_with_custom_default_message
-    Topic.validates_inclusion_of :title, :in => %w(a b c), :message => 'custom'
-    @topic.title = 'z'
-    @topic.errors.expects(:generate_message).with(:title, :inclusion, {:value => 'z', :default => 'custom'})
-    @topic.valid?
+    Person.validates_inclusion_of :title, :in => %w(a b c), :message => 'custom'
+    @person.title = 'z'
+    @person.errors.expects(:generate_message).with(:title, :inclusion, {:value => 'z', :default => 'custom'})
+    @person.valid?
   end
 
   # validates_exclusion_of w/ mocha
 
   def test_validates_exclusion_of_generates_message
-    Topic.validates_exclusion_of :title, :in => %w(a b c)
-    @topic.title = 'a'
-    @topic.errors.expects(:generate_message).with(:title, :exclusion, {:value => 'a', :default => nil})
-    @topic.valid?
+    Person.validates_exclusion_of :title, :in => %w(a b c)
+    @person.title = 'a'
+    @person.errors.expects(:generate_message).with(:title, :exclusion, {:value => 'a', :default => nil})
+    @person.valid?
   end
 
   def test_validates_exclusion_of_generates_message_with_custom_default_message
-    Topic.validates_exclusion_of :title, :in => %w(a b c), :message => 'custom'
-    @topic.title = 'a'
-    @topic.errors.expects(:generate_message).with(:title, :exclusion, {:value => 'a', :default => 'custom'})
-    @topic.valid?
+    Person.validates_exclusion_of :title, :in => %w(a b c), :message => 'custom'
+    @person.title = 'a'
+    @person.errors.expects(:generate_message).with(:title, :exclusion, {:value => 'a', :default => 'custom'})
+    @person.valid?
   end
 
   # validates_numericality_of without :only_integer w/ mocha
 
   def test_validates_numericality_of_generates_message
-    Topic.validates_numericality_of :title
-    @topic.title = 'a'
-    @topic.errors.expects(:generate_message).with(:title, :not_a_number, {:value => 'a', :default => nil})
-    @topic.valid?
+    Person.validates_numericality_of :title
+    @person.title = 'a'
+    @person.errors.expects(:generate_message).with(:title, :not_a_number, {:value => 'a', :default => nil})
+    @person.valid?
   end
 
   def test_validates_numericality_of_generates_message_with_custom_default_message
-    Topic.validates_numericality_of :title, :message => 'custom'
-    @topic.title = 'a'
-    @topic.errors.expects(:generate_message).with(:title, :not_a_number, {:value => 'a', :default => 'custom'})
-    @topic.valid?
+    Person.validates_numericality_of :title, :message => 'custom'
+    @person.title = 'a'
+    @person.errors.expects(:generate_message).with(:title, :not_a_number, {:value => 'a', :default => 'custom'})
+    @person.valid?
   end
 
   # validates_numericality_of with :only_integer w/ mocha
 
   def test_validates_numericality_of_only_integer_generates_message
-    Topic.validates_numericality_of :title, :only_integer => true
-    @topic.title = 'a'
-    @topic.errors.expects(:generate_message).with(:title, :not_a_number, {:value => 'a', :default => nil})
-    @topic.valid?
+    Person.validates_numericality_of :title, :only_integer => true
+    @person.title = 'a'
+    @person.errors.expects(:generate_message).with(:title, :not_a_number, {:value => 'a', :default => nil})
+    @person.valid?
   end
 
   def test_validates_numericality_of_only_integer_generates_message_with_custom_default_message
-    Topic.validates_numericality_of :title, :only_integer => true, :message => 'custom'
-    @topic.title = 'a'
-    @topic.errors.expects(:generate_message).with(:title, :not_a_number, {:value => 'a', :default => 'custom'})
-    @topic.valid?
+    Person.validates_numericality_of :title, :only_integer => true, :message => 'custom'
+    @person.title = 'a'
+    @person.errors.expects(:generate_message).with(:title, :not_a_number, {:value => 'a', :default => 'custom'})
+    @person.valid?
   end
 
   # validates_numericality_of :odd w/ mocha
 
   def test_validates_numericality_of_odd_generates_message
-    Topic.validates_numericality_of :title, :only_integer => true, :odd => true
-    @topic.title = 0
-    @topic.errors.expects(:generate_message).with(:title, :odd, {:value => 0, :default => nil})
-    @topic.valid?
+    Person.validates_numericality_of :title, :only_integer => true, :odd => true
+    @person.title = 0
+    @person.errors.expects(:generate_message).with(:title, :odd, {:value => 0, :default => nil})
+    @person.valid?
   end
 
   def test_validates_numericality_of_odd_generates_message_with_custom_default_message
-    Topic.validates_numericality_of :title, :only_integer => true, :odd => true, :message => 'custom'
-    @topic.title = 0
-    @topic.errors.expects(:generate_message).with(:title, :odd, {:value => 0, :default => 'custom'})
-    @topic.valid?
+    Person.validates_numericality_of :title, :only_integer => true, :odd => true, :message => 'custom'
+    @person.title = 0
+    @person.errors.expects(:generate_message).with(:title, :odd, {:value => 0, :default => 'custom'})
+    @person.valid?
   end
 
   # validates_numericality_of :less_than w/ mocha
 
   def test_validates_numericality_of_less_than_generates_message
-    Topic.validates_numericality_of :title, :only_integer => true, :less_than => 0
-    @topic.title = 1
-    @topic.errors.expects(:generate_message).with(:title, :less_than, {:value => 1, :count => 0, :default => nil})
-    @topic.valid?
+    Person.validates_numericality_of :title, :only_integer => true, :less_than => 0
+    @person.title = 1
+    @person.errors.expects(:generate_message).with(:title, :less_than, {:value => 1, :count => 0, :default => nil})
+    @person.valid?
   end
 
   def test_validates_numericality_of_odd_generates_message_with_custom_default_message
-    Topic.validates_numericality_of :title, :only_integer => true, :less_than => 0, :message => 'custom'
-    @topic.title = 1
-    @topic.errors.expects(:generate_message).with(:title, :less_than, {:value => 1, :count => 0, :default => 'custom'})
-    @topic.valid?
+    Person.validates_numericality_of :title, :only_integer => true, :less_than => 0, :message => 'custom'
+    @person.title = 1
+    @person.errors.expects(:generate_message).with(:title, :less_than, {:value => 1, :count => 0, :default => 'custom'})
+    @person.valid?
   end
 
   # validates_confirmation_of w/o mocha
 
   def test_validates_confirmation_of_finds_custom_model_key_translation
-    I18n.backend.store_translations 'en', :activerecord => {:errors => {:models => {:topic => {:attributes => {:title => {:confirmation => 'custom message'}}}}}}
-    I18n.backend.store_translations 'en', :activerecord => {:errors => {:messages => {:confirmation => 'global message'}}}
+    I18n.backend.store_translations 'en', :activemodel => {:errors => {:models => {:person => {:attributes => {:title => {:confirmation => 'custom message'}}}}}}
+    I18n.backend.store_translations 'en', :activemodel => {:errors => {:messages => {:confirmation => 'global message'}}}
 
-    Topic.validates_confirmation_of :title
-    @topic.title_confirmation = 'foo'
-    @topic.valid?
-    assert_equal ['custom message'], @topic.errors[:title]
+    Person.validates_confirmation_of :title
+    @person.title_confirmation = 'foo'
+    @person.valid?
+    assert_equal ['custom message'], @person.errors[:title]
   end
 
   def test_validates_confirmation_of_finds_global_default_translation
-    I18n.backend.store_translations 'en', :activerecord => {:errors => {:messages => {:confirmation => 'global message'}}}
+    I18n.backend.store_translations 'en', :activemodel => {:errors => {:messages => {:confirmation => 'global message'}}}
 
-    Topic.validates_confirmation_of :title
-    @topic.title_confirmation = 'foo'
-    @topic.valid?
-    assert_equal ['global message'], @topic.errors[:title]
+    Person.validates_confirmation_of :title
+    @person.title_confirmation = 'foo'
+    @person.valid?
+    assert_equal ['global message'], @person.errors[:title]
   end
 
   # validates_acceptance_of w/o mocha
 
   def test_validates_acceptance_of_finds_custom_model_key_translation
-    I18n.backend.store_translations 'en', :activerecord => {:errors => {:models => {:topic => {:attributes => {:title => {:accepted => 'custom message'}}}}}}
-    I18n.backend.store_translations 'en', :activerecord => {:errors => {:messages => {:accepted => 'global message'}}}
+    I18n.backend.store_translations 'en', :activemodel => {:errors => {:models => {:person => {:attributes => {:title => {:accepted => 'custom message'}}}}}}
+    I18n.backend.store_translations 'en', :activemodel => {:errors => {:messages => {:accepted => 'global message'}}}
 
-    Topic.validates_acceptance_of :title, :allow_nil => false
-    @topic.valid?
-    assert_equal ['custom message'], @topic.errors[:title]
+    Person.validates_acceptance_of :title, :allow_nil => false
+    @person.valid?
+    assert_equal ['custom message'], @person.errors[:title]
   end
 
   def test_validates_acceptance_of_finds_global_default_translation
-    I18n.backend.store_translations 'en', :activerecord => {:errors => {:messages => {:accepted => 'global message'}}}
+    I18n.backend.store_translations 'en', :activemodel => {:errors => {:messages => {:accepted => 'global message'}}}
 
-    Topic.validates_acceptance_of :title, :allow_nil => false
-    @topic.valid?
-    assert_equal ['global message'], @topic.errors[:title]
+    Person.validates_acceptance_of :title, :allow_nil => false
+    @person.valid?
+    assert_equal ['global message'], @person.errors[:title]
   end
 
   # validates_presence_of w/o mocha
 
   def test_validates_presence_of_finds_custom_model_key_translation
-    I18n.backend.store_translations 'en', :activerecord => {:errors => {:models => {:topic => {:attributes => {:title => {:blank => 'custom message'}}}}}}
-    I18n.backend.store_translations 'en', :activerecord => {:errors => {:messages => {:blank => 'global message'}}}
+    I18n.backend.store_translations 'en', :activemodel => {:errors => {:models => {:person => {:attributes => {:title => {:blank => 'custom message'}}}}}}
+    I18n.backend.store_translations 'en', :activemodel => {:errors => {:messages => {:blank => 'global message'}}}
 
-    Topic.validates_presence_of :title
-    @topic.valid?
-    assert_equal ['custom message'], @topic.errors[:title]
+    Person.validates_presence_of :title
+    @person.valid?
+    assert_equal ['custom message'], @person.errors[:title]
   end
 
   def test_validates_presence_of_finds_global_default_translation
-    I18n.backend.store_translations 'en', :activerecord => {:errors => {:messages => {:blank => 'global message'}}}
+    I18n.backend.store_translations 'en', :activemodel => {:errors => {:messages => {:blank => 'global message'}}}
 
-    Topic.validates_presence_of :title
-    @topic.valid?
-    assert_equal ['global message'], @topic.errors[:title]
+    Person.validates_presence_of :title
+    @person.valid?
+    assert_equal ['global message'], @person.errors[:title]
   end
 
   # validates_length_of :within w/o mocha
 
   def test_validates_length_of_within_finds_custom_model_key_translation
-    I18n.backend.store_translations 'en', :activerecord => {:errors => {:models => {:topic => {:attributes => {:title => {:too_short => 'custom message'}}}}}}
-    I18n.backend.store_translations 'en', :activerecord => {:errors => {:messages => {:too_short => 'global message'}}}
+    I18n.backend.store_translations 'en', :activemodel => {:errors => {:models => {:person => {:attributes => {:title => {:too_short => 'custom message'}}}}}}
+    I18n.backend.store_translations 'en', :activemodel => {:errors => {:messages => {:too_short => 'global message'}}}
 
-    Topic.validates_length_of :title, :within => 3..5
-    @topic.valid?
-    assert_equal ['custom message'], @topic.errors[:title]
+    Person.validates_length_of :title, :within => 3..5
+    @person.valid?
+    assert_equal ['custom message'], @person.errors[:title]
   end
 
   def test_validates_length_of_within_finds_global_default_translation
-    I18n.backend.store_translations 'en', :activerecord => {:errors => {:messages => {:too_short => 'global message'}}}
+    I18n.backend.store_translations 'en', :activemodel => {:errors => {:messages => {:too_short => 'global message'}}}
 
-    Topic.validates_length_of :title, :within => 3..5
-    @topic.valid?
-    assert_equal ['global message'], @topic.errors[:title]
+    Person.validates_length_of :title, :within => 3..5
+    @person.valid?
+    assert_equal ['global message'], @person.errors[:title]
   end
 
   # validates_length_of :is w/o mocha
 
   def test_validates_length_of_is_finds_custom_model_key_translation
-    I18n.backend.store_translations 'en', :activerecord => {:errors => {:models => {:topic => {:attributes => {:title => {:wrong_length => 'custom message'}}}}}}
-    I18n.backend.store_translations 'en', :activerecord => {:errors => {:messages => {:wrong_length => 'global message'}}}
+    I18n.backend.store_translations 'en', :activemodel => {:errors => {:models => {:person => {:attributes => {:title => {:wrong_length => 'custom message'}}}}}}
+    I18n.backend.store_translations 'en', :activemodel => {:errors => {:messages => {:wrong_length => 'global message'}}}
 
-    Topic.validates_length_of :title, :is => 5
-    @topic.valid?
-    assert_equal ['custom message'], @topic.errors[:title]
+    Person.validates_length_of :title, :is => 5
+    @person.valid?
+    assert_equal ['custom message'], @person.errors[:title]
   end
 
   def test_validates_length_of_is_finds_global_default_translation
-    I18n.backend.store_translations 'en', :activerecord => {:errors => {:messages => {:wrong_length => 'global message'}}}
+    I18n.backend.store_translations 'en', :activemodel => {:errors => {:messages => {:wrong_length => 'global message'}}}
 
-    Topic.validates_length_of :title, :is => 5
-    @topic.valid?
-    assert_equal ['global message'], @topic.errors[:title]
+    Person.validates_length_of :title, :is => 5
+    @person.valid?
+    assert_equal ['global message'], @person.errors[:title]
   end
 
   def test_validates_length_of_is_finds_custom_model_key_translation
-    I18n.backend.store_translations 'en', :activerecord => {:errors => {:models => {:topic => {:attributes => {:title => {:wrong_length => 'custom message'}}}}}}
-    I18n.backend.store_translations 'en', :activerecord => {:errors => {:messages => {:wrong_length => 'global message'}}}
+    I18n.backend.store_translations 'en', :activemodel => {:errors => {:models => {:person => {:attributes => {:title => {:wrong_length => 'custom message'}}}}}}
+    I18n.backend.store_translations 'en', :activemodel => {:errors => {:messages => {:wrong_length => 'global message'}}}
 
-    Topic.validates_length_of :title, :is => 5
-    @topic.valid?
-    assert_equal ['custom message'], @topic.errors[:title]
+    Person.validates_length_of :title, :is => 5
+    @person.valid?
+    assert_equal ['custom message'], @person.errors[:title]
   end
 
   def test_validates_length_of_is_finds_global_default_translation
-    I18n.backend.store_translations 'en', :activerecord => {:errors => {:messages => {:wrong_length => 'global message'}}}
+    I18n.backend.store_translations 'en', :activemodel => {:errors => {:messages => {:wrong_length => 'global message'}}}
 
-    Topic.validates_length_of :title, :is => 5
-    @topic.valid?
-    assert_equal ['global message'], @topic.errors[:title]
+    Person.validates_length_of :title, :is => 5
+    @person.valid?
+    assert_equal ['global message'], @person.errors[:title]
   end
 
 
   # validates_format_of w/o mocha
 
   def test_validates_format_of_finds_custom_model_key_translation
-    I18n.backend.store_translations 'en', :activerecord => {:errors => {:models => {:topic => {:attributes => {:title => {:invalid => 'custom message'}}}}}}
-    I18n.backend.store_translations 'en', :activerecord => {:errors => {:messages => {:invalid => 'global message'}}}
+    I18n.backend.store_translations 'en', :activemodel => {:errors => {:models => {:person => {:attributes => {:title => {:invalid => 'custom message'}}}}}}
+    I18n.backend.store_translations 'en', :activemodel => {:errors => {:messages => {:invalid => 'global message'}}}
 
-    Topic.validates_format_of :title, :with => /^[1-9][0-9]*$/
-    @topic.valid?
-    assert_equal ['custom message'], @topic.errors[:title]
+    Person.validates_format_of :title, :with => /^[1-9][0-9]*$/
+    @person.valid?
+    assert_equal ['custom message'], @person.errors[:title]
   end
 
   def test_validates_format_of_finds_global_default_translation
-    I18n.backend.store_translations 'en', :activerecord => {:errors => {:messages => {:invalid => 'global message'}}}
+    I18n.backend.store_translations 'en', :activemodel => {:errors => {:messages => {:invalid => 'global message'}}}
 
-    Topic.validates_format_of :title, :with => /^[1-9][0-9]*$/
-    @topic.valid?
-    assert_equal ['global message'], @topic.errors[:title]
+    Person.validates_format_of :title, :with => /^[1-9][0-9]*$/
+    @person.valid?
+    assert_equal ['global message'], @person.errors[:title]
   end
 
   # validates_inclusion_of w/o mocha
 
   def test_validates_inclusion_of_finds_custom_model_key_translation
-    I18n.backend.store_translations 'en', :activerecord => {:errors => {:models => {:topic => {:attributes => {:title => {:inclusion => 'custom message'}}}}}}
-    I18n.backend.store_translations 'en', :activerecord => {:errors => {:messages => {:inclusion => 'global message'}}}
+    I18n.backend.store_translations 'en', :activemodel => {:errors => {:models => {:person => {:attributes => {:title => {:inclusion => 'custom message'}}}}}}
+    I18n.backend.store_translations 'en', :activemodel => {:errors => {:messages => {:inclusion => 'global message'}}}
 
-    Topic.validates_inclusion_of :title, :in => %w(a b c)
-    @topic.valid?
-    assert_equal ['custom message'], @topic.errors[:title]
+    Person.validates_inclusion_of :title, :in => %w(a b c)
+    @person.valid?
+    assert_equal ['custom message'], @person.errors[:title]
   end
 
   def test_validates_inclusion_of_finds_global_default_translation
-    I18n.backend.store_translations 'en', :activerecord => {:errors => {:messages => {:inclusion => 'global message'}}}
+    I18n.backend.store_translations 'en', :activemodel => {:errors => {:messages => {:inclusion => 'global message'}}}
 
-    Topic.validates_inclusion_of :title, :in => %w(a b c)
-    @topic.valid?
-    assert_equal ['global message'], @topic.errors[:title]
+    Person.validates_inclusion_of :title, :in => %w(a b c)
+    @person.valid?
+    assert_equal ['global message'], @person.errors[:title]
   end
 
   # validates_exclusion_of w/o mocha
 
   def test_validates_exclusion_of_finds_custom_model_key_translation
-    I18n.backend.store_translations 'en', :activerecord => {:errors => {:models => {:topic => {:attributes => {:title => {:exclusion => 'custom message'}}}}}}
-    I18n.backend.store_translations 'en', :activerecord => {:errors => {:messages => {:exclusion => 'global message'}}}
+    I18n.backend.store_translations 'en', :activemodel => {:errors => {:models => {:person => {:attributes => {:title => {:exclusion => 'custom message'}}}}}}
+    I18n.backend.store_translations 'en', :activemodel => {:errors => {:messages => {:exclusion => 'global message'}}}
 
-    Topic.validates_exclusion_of :title, :in => %w(a b c)
-    @topic.title = 'a'
-    @topic.valid?
-    assert_equal ['custom message'], @topic.errors[:title]
+    Person.validates_exclusion_of :title, :in => %w(a b c)
+    @person.title = 'a'
+    @person.valid?
+    assert_equal ['custom message'], @person.errors[:title]
   end
 
   def test_validates_exclusion_of_finds_global_default_translation
-    I18n.backend.store_translations 'en', :activerecord => {:errors => {:messages => {:exclusion => 'global message'}}}
+    I18n.backend.store_translations 'en', :activemodel => {:errors => {:messages => {:exclusion => 'global message'}}}
 
-    Topic.validates_exclusion_of :title, :in => %w(a b c)
-    @topic.title = 'a'
-    @topic.valid?
-    assert_equal ['global message'], @topic.errors[:title]
+    Person.validates_exclusion_of :title, :in => %w(a b c)
+    @person.title = 'a'
+    @person.valid?
+    assert_equal ['global message'], @person.errors[:title]
   end
 
   # validates_numericality_of without :only_integer w/o mocha
 
   def test_validates_numericality_of_finds_custom_model_key_translation
-    I18n.backend.store_translations 'en', :activerecord => {:errors => {:models => {:topic => {:attributes => {:title => {:not_a_number => 'custom message'}}}}}}
-    I18n.backend.store_translations 'en', :activerecord => {:errors => {:messages => {:not_a_number => 'global message'}}}
+    I18n.backend.store_translations 'en', :activemodel => {:errors => {:models => {:person => {:attributes => {:title => {:not_a_number => 'custom message'}}}}}}
+    I18n.backend.store_translations 'en', :activemodel => {:errors => {:messages => {:not_a_number => 'global message'}}}
 
-    Topic.validates_numericality_of :title
-    @topic.title = 'a'
-    @topic.valid?
-    assert_equal ['custom message'], @topic.errors[:title]
+    Person.validates_numericality_of :title
+    @person.title = 'a'
+    @person.valid?
+    assert_equal ['custom message'], @person.errors[:title]
   end
 
   def test_validates_numericality_of_finds_global_default_translation
-    I18n.backend.store_translations 'en', :activerecord => {:errors => {:messages => {:not_a_number => 'global message'}}}
+    I18n.backend.store_translations 'en', :activemodel => {:errors => {:messages => {:not_a_number => 'global message'}}}
 
-    Topic.validates_numericality_of :title, :only_integer => true
-    @topic.title = 'a'
-    @topic.valid?
-    assert_equal ['global message'], @topic.errors[:title]
+    Person.validates_numericality_of :title, :only_integer => true
+    @person.title = 'a'
+    @person.valid?
+    assert_equal ['global message'], @person.errors[:title]
   end
 
   # validates_numericality_of with :only_integer w/o mocha
 
   def test_validates_numericality_of_only_integer_finds_custom_model_key_translation
-    I18n.backend.store_translations 'en', :activerecord => {:errors => {:models => {:topic => {:attributes => {:title => {:not_a_number => 'custom message'}}}}}}
-    I18n.backend.store_translations 'en', :activerecord => {:errors => {:messages => {:not_a_number => 'global message'}}}
+    I18n.backend.store_translations 'en', :activemodel => {:errors => {:models => {:person => {:attributes => {:title => {:not_a_number => 'custom message'}}}}}}
+    I18n.backend.store_translations 'en', :activemodel => {:errors => {:messages => {:not_a_number => 'global message'}}}
 
-    Topic.validates_numericality_of :title, :only_integer => true
-    @topic.title = 'a'
-    @topic.valid?
-    assert_equal ['custom message'], @topic.errors[:title]
+    Person.validates_numericality_of :title, :only_integer => true
+    @person.title = 'a'
+    @person.valid?
+    assert_equal ['custom message'], @person.errors[:title]
   end
 
   def test_validates_numericality_of_only_integer_finds_global_default_translation
-    I18n.backend.store_translations 'en', :activerecord => {:errors => {:messages => {:not_a_number => 'global message'}}}
+    I18n.backend.store_translations 'en', :activemodel => {:errors => {:messages => {:not_a_number => 'global message'}}}
 
-    Topic.validates_numericality_of :title, :only_integer => true
-    @topic.title = 'a'
-    @topic.valid?
-    assert_equal ['global message'], @topic.errors[:title]
+    Person.validates_numericality_of :title, :only_integer => true
+    @person.title = 'a'
+    @person.valid?
+    assert_equal ['global message'], @person.errors[:title]
   end
 
   # validates_numericality_of :odd w/o mocha
 
   def test_validates_numericality_of_odd_finds_custom_model_key_translation
-    I18n.backend.store_translations 'en', :activerecord => {:errors => {:models => {:topic => {:attributes => {:title => {:odd => 'custom message'}}}}}}
-    I18n.backend.store_translations 'en', :activerecord => {:errors => {:messages => {:odd => 'global message'}}}
+    I18n.backend.store_translations 'en', :activemodel => {:errors => {:models => {:person => {:attributes => {:title => {:odd => 'custom message'}}}}}}
+    I18n.backend.store_translations 'en', :activemodel => {:errors => {:messages => {:odd => 'global message'}}}
 
-    Topic.validates_numericality_of :title, :only_integer => true, :odd => true
-    @topic.title = 0
-    @topic.valid?
-    assert_equal ['custom message'], @topic.errors[:title]
+    Person.validates_numericality_of :title, :only_integer => true, :odd => true
+    @person.title = 0
+    @person.valid?
+    assert_equal ['custom message'], @person.errors[:title]
   end
 
   def test_validates_numericality_of_odd_finds_global_default_translation
-    I18n.backend.store_translations 'en', :activerecord => {:errors => {:messages => {:odd => 'global message'}}}
+    I18n.backend.store_translations 'en', :activemodel => {:errors => {:messages => {:odd => 'global message'}}}
 
-    Topic.validates_numericality_of :title, :only_integer => true, :odd => true
-    @topic.title = 0
-    @topic.valid?
-    assert_equal ['global message'], @topic.errors[:title]
+    Person.validates_numericality_of :title, :only_integer => true, :odd => true
+    @person.title = 0
+    @person.valid?
+    assert_equal ['global message'], @person.errors[:title]
   end
 
   # validates_numericality_of :less_than w/o mocha
 
   def test_validates_numericality_of_less_than_finds_custom_model_key_translation
-    I18n.backend.store_translations 'en', :activerecord => {:errors => {:models => {:topic => {:attributes => {:title => {:less_than => 'custom message'}}}}}}
-    I18n.backend.store_translations 'en', :activerecord => {:errors => {:messages => {:less_than => 'global message'}}}
+    I18n.backend.store_translations 'en', :activemodel => {:errors => {:models => {:person => {:attributes => {:title => {:less_than => 'custom message'}}}}}}
+    I18n.backend.store_translations 'en', :activemodel => {:errors => {:messages => {:less_than => 'global message'}}}
 
-    Topic.validates_numericality_of :title, :only_integer => true, :less_than => 0
-    @topic.title = 1
-    @topic.valid?
-    assert_equal ['custom message'], @topic.errors[:title]
+    Person.validates_numericality_of :title, :only_integer => true, :less_than => 0
+    @person.title = 1
+    @person.valid?
+    assert_equal ['custom message'], @person.errors[:title]
   end
 
   def test_validates_numericality_of_less_than_finds_global_default_translation
-    I18n.backend.store_translations 'en', :activerecord => {:errors => {:messages => {:less_than => 'global message'}}}
+    I18n.backend.store_translations 'en', :activemodel => {:errors => {:messages => {:less_than => 'global message'}}}
 
-    Topic.validates_numericality_of :title, :only_integer => true, :less_than => 0
-    @topic.title = 1
-    @topic.valid?
-    assert_equal ['global message'], @topic.errors[:title]
+    Person.validates_numericality_of :title, :only_integer => true, :less_than => 0
+    @person.title = 1
+    @person.valid?
+    assert_equal ['global message'], @person.errors[:title]
   end
 
   def test_validations_with_message_symbol_must_translate
-    I18n.backend.store_translations 'en', :activerecord => {:errors => {:messages => {:custom_error => "I am a custom error"}}}
-    Topic.validates_presence_of :title, :message => :custom_error
-    @topic.title = nil
-    @topic.valid?
-    assert_equal ["I am a custom error"], @topic.errors[:title]
+    I18n.backend.store_translations 'en', :activemodel => {:errors => {:messages => {:custom_error => "I am a custom error"}}}
+    Person.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', :activerecord => {:errors => {:models => {:topic => {:attributes => {:title => {:custom_error => "I am a custom error"}}}}}}
-    Topic.validates_presence_of :title, :message => :custom_error
-    @topic.title = nil
-    @topic.valid?
-    assert_equal ["I am a custom error"], @topic.errors[:title]
+    I18n.backend.store_translations 'en', :activemodel => {:errors => {:models => {:person => {:attributes => {:title => {:custom_error => "I am a custom error"}}}}}}
+    Person.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', :activerecord => {:errors => {:models => {:topic => {:custom_error => "I am a custom error"}}}}
-    Topic.validates_presence_of :title, :message => :custom_error
-    @topic.title = nil
-    @topic.valid?
-    assert_equal ["I am a custom error"], @topic.errors[:title]
+    I18n.backend.store_translations 'en', :activemodel => {:errors => {:models => {:person => {:custom_error => "I am a custom error"}}}}
+    Person.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
-    Topic.validates_presence_of :title, :message => "I am a custom error"
-    @topic.title = nil
-    @topic.valid?
-    assert_equal ["I am a custom error"], @topic.errors[:title]
+    Person.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
 
 end
\ No newline at end of file
diff --git a/activemodel/test/cases/validations/length_validation_test.rb b/activemodel/test/cases/validations/length_validation_test.rb
index e84e2815fa..ab725d9e1f 100644
--- a/activemodel/test/cases/validations/length_validation_test.rb
+++ b/activemodel/test/cases/validations/length_validation_test.rb
@@ -200,17 +200,6 @@ class LengthValidationTest < ActiveModel::TestCase
     end
   end
 
-  def test_validates_length_with_globally_modified_error_message
-    ActiveSupport::Deprecation.silence do
-      ActiveModel::Errors.default_error_messages[:too_short] = 'tu est trops petit hombre {{count}}'
-    end
-    Topic.validates_length_of :title, :minimum => 10
-    t = Topic.create(:title => 'too short')
-    assert !t.valid?
-
-    assert_equal ['tu est trops petit hombre 10'], t.errors[:title]
-  end
-
   def test_validates_length_of_nasty_params
     assert_raise(ArgumentError) { Topic.validates_length_of(:title, :minimum=>6, :maximum=>9) }
     assert_raise(ArgumentError) { Topic.validates_length_of(:title, :within=>6, :maximum=>9) }
diff --git a/activemodel/test/models/person.rb b/activemodel/test/models/person.rb
new file mode 100644
index 0000000000..6f787d9d3d
--- /dev/null
+++ b/activemodel/test/models/person.rb
@@ -0,0 +1,5 @@
+class Person
+  include ActiveModel::Validations
+
+  attr_accessor :title
+end
diff --git a/activerecord/lib/active_record/validations.rb b/activerecord/lib/active_record/validations.rb
index c2e0c4a9ae..a9e6654aec 100644
--- a/activerecord/lib/active_record/validations.rb
+++ b/activerecord/lib/active_record/validations.rb
@@ -15,6 +15,86 @@ module ActiveRecord
   end
 
   class Errors < ActiveModel::Errors
+    class << self
+      def default_error_messages
+        message = "Errors.default_error_messages has been deprecated. Please use I18n.translate('activerecord.errors.messages')."
+        ActiveSupport::Deprecation.warn(message)
+
+        I18n.translate 'activerecord.errors.messages'
+      end
+    end
+
+    # Returns all the full error messages in an array.
+    #
+    #   class Company < ActiveRecord::Base
+    #     validates_presence_of :name, :address, :email
+    #     validates_length_of :name, :in => 5..30
+    #   end
+    #
+    #   company = Company.create(:address => '123 First St.')
+    #   company.errors.full_messages # =>
+    #     ["Name is too short (minimum is 5 characters)", "Name can't be blank", "Address can't be blank"]
+    def full_messages(options = {})
+      full_messages = []
+
+      each do |attribute, messages|
+        next if messages.empty?
+
+        if attribute == :base
+          messages.each {|m| full_messages << m }
+        else
+          attr_name = @base.class.human_attribute_name(attribute.to_s)
+          prefix = attr_name + I18n.t('activerecord.errors.format.separator', :default => ' ')
+          messages.each do |m|
+            full_messages <<  "#{prefix}#{m}"
+          end
+        end
+      end
+
+      full_messages
+    end
+
+    # Translates an error message in it's default scope (<tt>activerecord.errrors.messages</tt>).
+    # Error messages are first looked up in <tt>models.MODEL.attributes.ATTRIBUTE.MESSAGE</tt>, if it's not there, 
+    # it's looked up in <tt>models.MODEL.MESSAGE</tt> and if that is not there it returns the translation of the 
+    # default message (e.g. <tt>activerecord.errors.messages.MESSAGE</tt>). The translated model name, 
+    # translated attribute name and the value are available for interpolation.
+    #
+    # When using inheritence 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:
+    # 
+    # <ol>
+    # <li><tt>activerecord.errors.models.admin.attributes.title.blank</tt></li>
+    # <li><tt>activerecord.errors.models.admin.blank</tt></li>
+    # <li><tt>activerecord.errors.models.user.attributes.title.blank</tt></li>
+    # <li><tt>activerecord.errors.models.user.blank</tt></li>
+    # <li><tt>activerecord.errors.messages.blank</tt></li>
+    # <li>any default you provided through the +options+ hash (in the activerecord.errors scope)</li>
+    # </ol>
+    def generate_message(attribute, message = :invalid, options = {})
+      message, options[:default] = options[:default], message if options[:default].is_a?(Symbol)
+
+      defaults = @base.class.self_and_descendants_from_active_record.map do |klass|
+        [ :"models.#{klass.name.underscore}.attributes.#{attribute}.#{message}", 
+          :"models.#{klass.name.underscore}.#{message}" ]
+      end
+      
+      defaults << options.delete(:default)
+      defaults = defaults.compact.flatten << :"messages.#{message}"
+
+      key = defaults.shift
+      value = @base.respond_to?(attribute) ? @base.send(attribute) : nil
+
+      options = { :default => defaults,
+        :model => @base.class.human_name,
+        :attribute => @base.class.human_attribute_name(attribute.to_s),
+        :value => value,
+        :scope => [:activerecord, :errors]
+      }.merge(options)
+
+      I18n.translate(key, options)
+    end
   end
 
   module Validations
@@ -24,6 +104,8 @@ module ActiveRecord
       base.send :include, ActiveModel::Validations
       base.send :include, InstanceMethods
 
+      base.define_callbacks :validate_on_create, :validate_on_update
+
       base.class_eval do
         alias_method_chain :save, :validation
         alias_method_chain :save!, :validation
@@ -66,10 +148,43 @@ module ActiveRecord
         end
       end
 
+      # Runs all the specified validations and returns true if no errors were added otherwise false.
+      def valid?
+        errors.clear
+
+        run_callbacks(:validate)
+
+        validate if respond_to?(:validate)
+
+        if new_record?
+          run_callbacks(:validate_on_create)
+          validate_on_create if respond_to?(:validate_on_create)
+        else
+          run_callbacks(:validate_on_update)
+          validate_on_update if respond_to?(:validate_on_update)
+        end
+
+        errors.empty?
+      end
+
       # Returns the Errors object that holds all information about attribute error messages.
       def errors
         @errors ||= Errors.new(self)
       end
+
+      def get_attribute_value(attribute)
+        respond_to?(attribute.to_sym) ? send(attribute.to_sym) : self[attribute.to_sym]
+      end
+
+      protected
+
+      # Overwrite this method for validation checks used only on creation.
+      def validate_on_create
+      end
+
+      # Overwrite this method for validation checks used only on updates.
+      def validate_on_update
+      end
     end
 
   end
diff --git a/activerecord/test/cases/validations/i18n_generate_message_validation_test.rb b/activerecord/test/cases/validations/i18n_generate_message_validation_test.rb
index e7ba6f2155..29c10de4fe 100644
--- a/activerecord/test/cases/validations/i18n_generate_message_validation_test.rb
+++ b/activerecord/test/cases/validations/i18n_generate_message_validation_test.rb
@@ -25,6 +25,135 @@ class I18nGenerateMessageValidationTest < Test::Unit::TestCase
     end
   end
 
+  # validates_inclusion_of: generate_message(attr_name, :inclusion, :default => configuration[:message], :value => value)
+  def test_generate_message_inclusion_with_default_message
+    assert_equal 'is not included in the list', @topic.errors.generate_message(:title, :inclusion, :default => nil, :value => 'title')
+  end
+
+  def test_generate_message_inclusion_with_custom_message
+    assert_equal 'custom message title', @topic.errors.generate_message(:title, :inclusion, :default => 'custom message {{value}}', :value => 'title')
+  end
+
+  # validates_exclusion_of: generate_message(attr_name, :exclusion, :default => configuration[:message], :value => value)
+  def test_generate_message_exclusion_with_default_message
+    assert_equal 'is reserved', @topic.errors.generate_message(:title, :exclusion, :default => nil, :value => 'title')
+  end
+
+  def test_generate_message_exclusion_with_custom_message
+    assert_equal 'custom message title', @topic.errors.generate_message(:title, :exclusion, :default => 'custom message {{value}}', :value => 'title')
+  end
+
+  # validates_associated: generate_message(attr_name, :invalid, :default => configuration[:message], :value => value)
+  # validates_format_of:  generate_message(attr_name, :invalid, :default => configuration[:message], :value => value)
+  def test_generate_message_invalid_with_default_message
+    assert_equal 'is invalid', @topic.errors.generate_message(:title, :invalid, :default => nil, :value => 'title')
+  end
+
+  def test_generate_message_invalid_with_custom_message
+    assert_equal 'custom message title', @topic.errors.generate_message(:title, :invalid, :default => 'custom message {{value}}', :value => 'title')
+  end
+
+  # validates_confirmation_of: generate_message(attr_name, :confirmation, :default => configuration[:message])
+  def test_generate_message_confirmation_with_default_message
+    assert_equal "doesn't match confirmation", @topic.errors.generate_message(:title, :confirmation, :default => nil)
+  end
+
+  def test_generate_message_confirmation_with_custom_message
+    assert_equal 'custom message', @topic.errors.generate_message(:title, :confirmation, :default => 'custom message')
+  end
+
+  # validates_acceptance_of: generate_message(attr_name, :accepted, :default => configuration[:message])
+  def test_generate_message_accepted_with_default_message
+    assert_equal "must be accepted", @topic.errors.generate_message(:title, :accepted, :default => nil)
+  end
+
+  def test_generate_message_accepted_with_custom_message
+    assert_equal 'custom message', @topic.errors.generate_message(:title, :accepted, :default => 'custom message')
+  end
+
+  # add_on_empty: generate_message(attr, :empty, :default => custom_message)
+  def test_generate_message_empty_with_default_message
+    assert_equal "can't be empty", @topic.errors.generate_message(:title, :empty, :default => nil)
+  end
+
+  def test_generate_message_empty_with_custom_message
+    assert_equal 'custom message', @topic.errors.generate_message(:title, :empty, :default => 'custom message')
+  end
+
+  # add_on_blank: generate_message(attr, :blank, :default => custom_message)
+  def test_generate_message_blank_with_default_message
+    assert_equal "can't be blank", @topic.errors.generate_message(:title, :blank, :default => nil)
+  end
+
+  def test_generate_message_blank_with_custom_message
+    assert_equal 'custom message', @topic.errors.generate_message(:title, :blank, :default => 'custom message')
+  end
+
+  # validates_length_of: generate_message(attr, :too_long, :default => options[:too_long], :count => option_value.end)
+  def test_generate_message_too_long_with_default_message
+    assert_equal "is too long (maximum is 10 characters)", @topic.errors.generate_message(:title, :too_long, :default => nil, :count => 10)
+  end
+
+  def test_generate_message_too_long_with_custom_message
+    assert_equal 'custom message 10', @topic.errors.generate_message(:title, :too_long, :default => 'custom message {{count}}', :count => 10)
+  end
+
+  # validates_length_of: generate_message(attr, :too_short, :default => options[:too_short], :count => option_value.begin)
+  def test_generate_message_too_short_with_default_message
+    assert_equal "is too short (minimum is 10 characters)", @topic.errors.generate_message(:title, :too_short, :default => nil, :count => 10)
+  end
+
+  def test_generate_message_too_short_with_custom_message
+    assert_equal 'custom message 10', @topic.errors.generate_message(:title, :too_short, :default => 'custom message {{count}}', :count => 10)
+  end
+
+  # validates_length_of: generate_message(attr, key, :default => custom_message, :count => option_value)
+  def test_generate_message_wrong_length_with_default_message
+    assert_equal "is the wrong length (should be 10 characters)", @topic.errors.generate_message(:title, :wrong_length, :default => nil, :count => 10)
+  end
+
+  def test_generate_message_wrong_length_with_custom_message
+    assert_equal 'custom message 10', @topic.errors.generate_message(:title, :wrong_length, :default => 'custom message {{count}}', :count => 10)
+  end
+
+  # validates_numericality_of: generate_message(attr_name, :not_a_number, :value => raw_value, :default => configuration[:message])
+  def test_generate_message_not_a_number_with_default_message
+    assert_equal "is not a number", @topic.errors.generate_message(:title, :not_a_number, :default => nil, :value => 'title')
+  end
+
+  def test_generate_message_not_a_number_with_custom_message
+    assert_equal 'custom message title', @topic.errors.generate_message(:title, :not_a_number, :default => 'custom message {{value}}', :value => 'title')
+  end
+
+  # validates_numericality_of: generate_message(attr_name, option, :value => raw_value, :default => configuration[:message])
+  def test_generate_message_greater_than_with_default_message
+    assert_equal "must be greater than 10", @topic.errors.generate_message(:title, :greater_than, :default => nil, :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", @topic.errors.generate_message(:title, :greater_than_or_equal_to, :default => nil, :value => 'title', :count => 10)
+  end
+
+  def test_generate_message_equal_to_with_default_message
+    assert_equal "must be equal to 10", @topic.errors.generate_message(:title, :equal_to, :default => nil, :value => 'title', :count => 10)
+  end
+
+  def test_generate_message_less_than_with_default_message
+    assert_equal "must be less than 10", @topic.errors.generate_message(:title, :less_than, :default => nil, :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", @topic.errors.generate_message(:title, :less_than_or_equal_to, :default => nil, :value => 'title', :count => 10)
+  end
+
+  def test_generate_message_odd_with_default_message
+    assert_equal "must be odd", @topic.errors.generate_message(:title, :odd, :default => nil, :value => 'title', :count => 10)
+  end
+
+  def test_generate_message_even_with_default_message
+    assert_equal "must be even", @topic.errors.generate_message(:title, :even, :default => nil, :value => 'title', :count => 10)
+  end
+
   # validates_uniqueness_of: generate_message(attr_name, :taken, :default => configuration[:message])
   def test_generate_message_taken_with_default_message
     assert_equal "has already been taken", @topic.errors.generate_message(:title, :taken, :default => nil, :value => 'title')
diff --git a/activerecord/test/cases/validations/i18n_validation_test.rb b/activerecord/test/cases/validations/i18n_validation_test.rb
index c453672815..4b34a65bb7 100644
--- a/activerecord/test/cases/validations/i18n_validation_test.rb
+++ b/activerecord/test/cases/validations/i18n_validation_test.rb
@@ -38,6 +38,80 @@ class I18nValidationTest < ActiveRecord::TestCase
     end
   end
 
+  def test_default_error_messages_is_deprecated
+    assert_deprecated('Errors.default_error_messages') do
+      ActiveRecord::Errors.default_error_messages
+    end
+  end
+
+  def test_errors_generate_message_translates_custom_model_attribute_key
+    I18n.expects(:translate).with(
+      :topic,
+      { :count => 1,
+        :default => ['Topic'],
+        :scope => [:activerecord, :models]
+      }
+    ).returns('Topic')
+
+    I18n.expects(:translate).with(
+      :"topic.title",
+      { :count => 1,
+        :default => ['Title'],
+        :scope => [:activerecord, :attributes]
+      }
+    ).returns('Title')
+
+    I18n.expects(:translate).with(
+      :"models.topic.attributes.title.invalid",
+      :value => nil,
+      :scope => [:activerecord, :errors],
+      :default => [
+        :"models.topic.invalid",
+        'default from class def error 1',
+        :"messages.invalid"],
+      :attribute => "Title",
+      :model => "Topic"
+    ).returns('default from class def error 1')
+
+    @topic.errors.generate_message :title, :invalid, :default => 'default from class def error 1'
+  end
+
+  def test_errors_generate_message_translates_custom_model_attribute_keys_with_sti
+
+    I18n.expects(:translate).with(
+      :reply,
+      { :count => 1,
+        :default => [:topic, 'Reply'],
+        :scope => [:activerecord, :models]
+      }
+    ).returns('Reply')
+
+    I18n.expects(:translate).with(
+      :"reply.title",
+      { :count => 1,
+        :default => [:'topic.title', 'Title'],
+        :scope => [:activerecord, :attributes]
+      }
+    ).returns('Title')
+
+    I18n.expects(:translate).with(
+      :"models.reply.attributes.title.invalid",
+      :value => nil,
+      :scope => [:activerecord, :errors],
+      :default => [
+        :"models.reply.invalid",
+        :"models.topic.attributes.title.invalid",
+        :"models.topic.invalid",
+        'default from class def',
+        :"messages.invalid"],
+      :model => 'Reply',
+      :attribute => 'Title'
+    ).returns("default from class def")
+
+    Reply.new.errors.generate_message :title, :invalid, :default => 'default from class def'
+
+  end
+
   # validates_uniqueness_of w/ mocha
 
   def test_validates_uniqueness_of_generates_message
@@ -86,4 +160,543 @@ class I18nValidationTest < ActiveRecord::TestCase
     replied_topic.valid?
     assert_equal ['global message'], replied_topic.errors[:replies]
   end
+
+  def test_errors_add_on_empty_generates_message
+    @topic.errors.expects(:generate_message).with(:title, :empty, {:default => nil})
+    @topic.errors.add_on_empty :title
+  end
+
+  def test_errors_add_on_empty_generates_message_with_custom_default_message
+    @topic.errors.expects(:generate_message).with(:title, :empty, {:default => 'custom'})
+    @topic.errors.add_on_empty :title, 'custom'
+  end
+
+  def test_errors_add_on_blank_generates_message
+    @topic.errors.expects(:generate_message).with(:title, :blank, {:default => nil})
+    @topic.errors.add_on_blank :title
+  end
+
+  def test_errors_add_on_blank_generates_message_with_custom_default_message
+    @topic.errors.expects(:generate_message).with(:title, :blank, {:default => 'custom'})
+    @topic.errors.add_on_blank :title, 'custom'
+  end
+
+  def test_errors_full_messages_translates_human_attribute_name_for_model_attributes
+    @topic.errors.add('title', 'empty')
+    I18n.expects(:translate).with(:"topic.title", :default => ['Title'], :scope => [:activerecord, :attributes], :count => 1).returns('Title')
+    @topic.errors.full_messages :locale => 'en'
+  end
+
+  # ActiveRecord::Validations
+  # validates_confirmation_of w/ mocha
+  def test_validates_confirmation_of_generates_message
+    Topic.validates_confirmation_of :title
+    @topic.title_confirmation = 'foo'
+    @topic.errors.expects(:generate_message).with(:title, :confirmation, {:default => nil})
+    @topic.valid?
+  end
+
+  def test_validates_confirmation_of_generates_message_with_custom_default_message
+    Topic.validates_confirmation_of :title, :message => 'custom'
+    @topic.title_confirmation = 'foo'
+    @topic.errors.expects(:generate_message).with(:title, :confirmation, {:default => 'custom'})
+    @topic.valid?
+  end
+
+  # validates_acceptance_of w/ mocha
+
+  def test_validates_acceptance_of_generates_message
+    Topic.validates_acceptance_of :title, :allow_nil => false
+    @topic.errors.expects(:generate_message).with(:title, :accepted, {:default => nil})
+    @topic.valid?
+  end
+
+  def test_validates_acceptance_of_generates_message_with_custom_default_message
+    Topic.validates_acceptance_of :title, :message => 'custom', :allow_nil => false
+    @topic.errors.expects(:generate_message).with(:title, :accepted, {:default => 'custom'})
+    @topic.valid?
+  end
+
+  # validates_presence_of w/ mocha
+
+  def test_validates_presence_of_generates_message
+    Topic.validates_presence_of :title
+    @topic.errors.expects(:generate_message).with(:title, :blank, {:default => nil})
+    @topic.valid?
+  end
+
+  def test_validates_presence_of_generates_message_with_custom_default_message
+    Topic.validates_presence_of :title, :message => 'custom'
+    @topic.errors.expects(:generate_message).with(:title, :blank, {:default => 'custom'})
+    @topic.valid?
+  end
+
+  def test_validates_length_of_within_generates_message_with_title_too_short
+    Topic.validates_length_of :title, :within => 3..5
+    @topic.errors.expects(:generate_message).with(:title, :too_short, {:count => 3, :default => nil})
+    @topic.valid?
+  end
+
+  def test_validates_length_of_within_generates_message_with_title_too_short_and_custom_default_message
+    Topic.validates_length_of :title, :within => 3..5, :too_short => 'custom'
+    @topic.errors.expects(:generate_message).with(:title, :too_short, {:count => 3, :default => 'custom'})
+    @topic.valid?
+  end
+
+  def test_validates_length_of_within_generates_message_with_title_too_long
+    Topic.validates_length_of :title, :within => 3..5
+    @topic.title = 'this title is too long'
+    @topic.errors.expects(:generate_message).with(:title, :too_long, {:count => 5, :default => nil})
+    @topic.valid?
+  end
+
+  def test_validates_length_of_within_generates_message_with_title_too_long_and_custom_default_message
+    Topic.validates_length_of :title, :within => 3..5, :too_long => 'custom'
+    @topic.title = 'this title is too long'
+    @topic.errors.expects(:generate_message).with(:title, :too_long, {:count => 5, :default => 'custom'})
+    @topic.valid?
+  end
+
+  # validates_length_of :within w/ mocha
+
+  def test_validates_length_of_within_generates_message_with_title_too_short
+    Topic.validates_length_of :title, :within => 3..5
+    @topic.errors.expects(:generate_message).with(:title, :too_short, {:count => 3, :default => nil})
+    @topic.valid?
+  end
+
+  def test_validates_length_of_within_generates_message_with_title_too_short_and_custom_default_message
+    Topic.validates_length_of :title, :within => 3..5, :too_short => 'custom'
+    @topic.errors.expects(:generate_message).with(:title, :too_short, {:count => 3, :default => 'custom'})
+    @topic.valid?
+  end
+
+  def test_validates_length_of_within_generates_message_with_title_too_long
+    Topic.validates_length_of :title, :within => 3..5
+    @topic.title = 'this title is too long'
+    @topic.errors.expects(:generate_message).with(:title, :too_long, {:count => 5, :default => nil})
+    @topic.valid?
+  end
+
+  def test_validates_length_of_within_generates_message_with_title_too_long_and_custom_default_message
+    Topic.validates_length_of :title, :within => 3..5, :too_long => 'custom'
+    @topic.title = 'this title is too long'
+    @topic.errors.expects(:generate_message).with(:title, :too_long, {:count => 5, :default => 'custom'})
+    @topic.valid?
+  end
+
+  # validates_length_of :is w/ mocha
+
+  def test_validates_length_of_is_generates_message
+    Topic.validates_length_of :title, :is => 5
+    @topic.errors.expects(:generate_message).with(:title, :wrong_length, {:count => 5, :default => nil})
+    @topic.valid?
+  end
+
+  def test_validates_length_of_is_generates_message_with_custom_default_message
+    Topic.validates_length_of :title, :is => 5, :message => 'custom'
+    @topic.errors.expects(:generate_message).with(:title, :wrong_length, {:count => 5, :default => 'custom'})
+    @topic.valid?
+  end
+
+  # validates_format_of w/ mocha
+
+  def test_validates_format_of_generates_message
+    Topic.validates_format_of :title, :with => /^[1-9][0-9]*$/
+    @topic.title = '72x'
+    @topic.errors.expects(:generate_message).with(:title, :invalid, {:value => '72x', :default => nil})
+    @topic.valid?
+  end
+
+  def test_validates_format_of_generates_message_with_custom_default_message
+    Topic.validates_format_of :title, :with => /^[1-9][0-9]*$/, :message => 'custom'
+    @topic.title = '72x'
+    @topic.errors.expects(:generate_message).with(:title, :invalid, {:value => '72x', :default => 'custom'})
+    @topic.valid?
+  end
+
+  # validates_inclusion_of w/ mocha
+
+  def test_validates_inclusion_of_generates_message
+    Topic.validates_inclusion_of :title, :in => %w(a b c)
+    @topic.title = 'z'
+    @topic.errors.expects(:generate_message).with(:title, :inclusion, {:value => 'z', :default => nil})
+    @topic.valid?
+  end
+
+  def test_validates_inclusion_of_generates_message_with_custom_default_message
+    Topic.validates_inclusion_of :title, :in => %w(a b c), :message => 'custom'
+    @topic.title = 'z'
+    @topic.errors.expects(:generate_message).with(:title, :inclusion, {:value => 'z', :default => 'custom'})
+    @topic.valid?
+  end
+
+  # validates_exclusion_of w/ mocha
+
+  def test_validates_exclusion_of_generates_message
+    Topic.validates_exclusion_of :title, :in => %w(a b c)
+    @topic.title = 'a'
+    @topic.errors.expects(:generate_message).with(:title, :exclusion, {:value => 'a', :default => nil})
+    @topic.valid?
+  end
+
+  def test_validates_exclusion_of_generates_message_with_custom_default_message
+    Topic.validates_exclusion_of :title, :in => %w(a b c), :message => 'custom'
+    @topic.title = 'a'
+    @topic.errors.expects(:generate_message).with(:title, :exclusion, {:value => 'a', :default => 'custom'})
+    @topic.valid?
+  end
+
+  # validates_numericality_of without :only_integer w/ mocha
+
+  def test_validates_numericality_of_generates_message
+    Topic.validates_numericality_of :title
+    @topic.title = 'a'
+    @topic.errors.expects(:generate_message).with(:title, :not_a_number, {:value => 'a', :default => nil})
+    @topic.valid?
+  end
+
+  def test_validates_numericality_of_generates_message_with_custom_default_message
+    Topic.validates_numericality_of :title, :message => 'custom'
+    @topic.title = 'a'
+    @topic.errors.expects(:generate_message).with(:title, :not_a_number, {:value => 'a', :default => 'custom'})
+    @topic.valid?
+  end
+
+  # validates_numericality_of with :only_integer w/ mocha
+
+  def test_validates_numericality_of_only_integer_generates_message
+    Topic.validates_numericality_of :title, :only_integer => true
+    @topic.title = 'a'
+    @topic.errors.expects(:generate_message).with(:title, :not_a_number, {:value => 'a', :default => nil})
+    @topic.valid?
+  end
+
+  def test_validates_numericality_of_only_integer_generates_message_with_custom_default_message
+    Topic.validates_numericality_of :title, :only_integer => true, :message => 'custom'
+    @topic.title = 'a'
+    @topic.errors.expects(:generate_message).with(:title, :not_a_number, {:value => 'a', :default => 'custom'})
+    @topic.valid?
+  end
+
+  # validates_numericality_of :odd w/ mocha
+
+  def test_validates_numericality_of_odd_generates_message
+    Topic.validates_numericality_of :title, :only_integer => true, :odd => true
+    @topic.title = 0
+    @topic.errors.expects(:generate_message).with(:title, :odd, {:value => 0, :default => nil})
+    @topic.valid?
+  end
+
+  def test_validates_numericality_of_odd_generates_message_with_custom_default_message
+    Topic.validates_numericality_of :title, :only_integer => true, :odd => true, :message => 'custom'
+    @topic.title = 0
+    @topic.errors.expects(:generate_message).with(:title, :odd, {:value => 0, :default => 'custom'})
+    @topic.valid?
+  end
+
+  # validates_numericality_of :less_than w/ mocha
+
+  def test_validates_numericality_of_less_than_generates_message
+    Topic.validates_numericality_of :title, :only_integer => true, :less_than => 0
+    @topic.title = 1
+    @topic.errors.expects(:generate_message).with(:title, :less_than, {:value => 1, :count => 0, :default => nil})
+    @topic.valid?
+  end
+
+  def test_validates_numericality_of_odd_generates_message_with_custom_default_message
+    Topic.validates_numericality_of :title, :only_integer => true, :less_than => 0, :message => 'custom'
+    @topic.title = 1
+    @topic.errors.expects(:generate_message).with(:title, :less_than, {:value => 1, :count => 0, :default => 'custom'})
+    @topic.valid?
+  end
+
+  # validates_confirmation_of w/o mocha
+
+  def test_validates_confirmation_of_finds_custom_model_key_translation
+    I18n.backend.store_translations 'en', :activerecord => {:errors => {:models => {:topic => {:attributes => {:title => {:confirmation => 'custom message'}}}}}}
+    I18n.backend.store_translations 'en', :activerecord => {:errors => {:messages => {:confirmation => 'global message'}}}
+
+    Topic.validates_confirmation_of :title
+    @topic.title_confirmation = 'foo'
+    @topic.valid?
+    assert_equal ['custom message'], @topic.errors[:title]
+  end
+
+  def test_validates_confirmation_of_finds_global_default_translation
+    I18n.backend.store_translations 'en', :activerecord => {:errors => {:messages => {:confirmation => 'global message'}}}
+
+    Topic.validates_confirmation_of :title
+    @topic.title_confirmation = 'foo'
+    @topic.valid?
+    assert_equal ['global message'], @topic.errors[:title]
+  end
+
+  # validates_acceptance_of w/o mocha
+
+  def test_validates_acceptance_of_finds_custom_model_key_translation
+    I18n.backend.store_translations 'en', :activerecord => {:errors => {:models => {:topic => {:attributes => {:title => {:accepted => 'custom message'}}}}}}
+    I18n.backend.store_translations 'en', :activerecord => {:errors => {:messages => {:accepted => 'global message'}}}
+
+    Topic.validates_acceptance_of :title, :allow_nil => false
+    @topic.valid?
+    assert_equal ['custom message'], @topic.errors[:title]
+  end
+
+  def test_validates_acceptance_of_finds_global_default_translation
+    I18n.backend.store_translations 'en', :activerecord => {:errors => {:messages => {:accepted => 'global message'}}}
+
+    Topic.validates_acceptance_of :title, :allow_nil => false
+    @topic.valid?
+    assert_equal ['global message'], @topic.errors[:title]
+  end
+
+  # validates_presence_of w/o mocha
+
+  def test_validates_presence_of_finds_custom_model_key_translation
+    I18n.backend.store_translations 'en', :activerecord => {:errors => {:models => {:topic => {:attributes => {:title => {:blank => 'custom message'}}}}}}
+    I18n.backend.store_translations 'en', :activerecord => {:errors => {:messages => {:blank => 'global message'}}}
+
+    Topic.validates_presence_of :title
+    @topic.valid?
+    assert_equal ['custom message'], @topic.errors[:title]
+  end
+
+  def test_validates_presence_of_finds_global_default_translation
+    I18n.backend.store_translations 'en', :activerecord => {:errors => {:messages => {:blank => 'global message'}}}
+
+    Topic.validates_presence_of :title
+    @topic.valid?
+    assert_equal ['global message'], @topic.errors[:title]
+  end
+
+  # validates_length_of :within w/o mocha
+
+  def test_validates_length_of_within_finds_custom_model_key_translation
+    I18n.backend.store_translations 'en', :activerecord => {:errors => {:models => {:topic => {:attributes => {:title => {:too_short => 'custom message'}}}}}}
+    I18n.backend.store_translations 'en', :activerecord => {:errors => {:messages => {:too_short => 'global message'}}}
+
+    Topic.validates_length_of :title, :within => 3..5
+    @topic.valid?
+    assert_equal ['custom message'], @topic.errors[:title]
+  end
+
+  def test_validates_length_of_within_finds_global_default_translation
+    I18n.backend.store_translations 'en', :activerecord => {:errors => {:messages => {:too_short => 'global message'}}}
+
+    Topic.validates_length_of :title, :within => 3..5
+    @topic.valid?
+    assert_equal ['global message'], @topic.errors[:title]
+  end
+
+  # validates_length_of :is w/o mocha
+
+  def test_validates_length_of_is_finds_custom_model_key_translation
+    I18n.backend.store_translations 'en', :activerecord => {:errors => {:models => {:topic => {:attributes => {:title => {:wrong_length => 'custom message'}}}}}}
+    I18n.backend.store_translations 'en', :activerecord => {:errors => {:messages => {:wrong_length => 'global message'}}}
+
+    Topic.validates_length_of :title, :is => 5
+    @topic.valid?
+    assert_equal ['custom message'], @topic.errors[:title]
+  end
+
+  def test_validates_length_of_is_finds_global_default_translation
+    I18n.backend.store_translations 'en', :activerecord => {:errors => {:messages => {:wrong_length => 'global message'}}}
+
+    Topic.validates_length_of :title, :is => 5
+    @topic.valid?
+    assert_equal ['global message'], @topic.errors[:title]
+  end
+
+  def test_validates_length_of_is_finds_custom_model_key_translation
+    I18n.backend.store_translations 'en', :activerecord => {:errors => {:models => {:topic => {:attributes => {:title => {:wrong_length => 'custom message'}}}}}}
+    I18n.backend.store_translations 'en', :activerecord => {:errors => {:messages => {:wrong_length => 'global message'}}}
+
+    Topic.validates_length_of :title, :is => 5
+    @topic.valid?
+    assert_equal ['custom message'], @topic.errors[:title]
+  end
+
+  def test_validates_length_of_is_finds_global_default_translation
+    I18n.backend.store_translations 'en', :activerecord => {:errors => {:messages => {:wrong_length => 'global message'}}}
+
+    Topic.validates_length_of :title, :is => 5
+    @topic.valid?
+    assert_equal ['global message'], @topic.errors[:title]
+  end
+
+
+  # validates_format_of w/o mocha
+
+  def test_validates_format_of_finds_custom_model_key_translation
+    I18n.backend.store_translations 'en', :activerecord => {:errors => {:models => {:topic => {:attributes => {:title => {:invalid => 'custom message'}}}}}}
+    I18n.backend.store_translations 'en', :activerecord => {:errors => {:messages => {:invalid => 'global message'}}}
+
+    Topic.validates_format_of :title, :with => /^[1-9][0-9]*$/
+    @topic.valid?
+    assert_equal ['custom message'], @topic.errors[:title]
+  end
+
+  def test_validates_format_of_finds_global_default_translation
+    I18n.backend.store_translations 'en', :activerecord => {:errors => {:messages => {:invalid => 'global message'}}}
+
+    Topic.validates_format_of :title, :with => /^[1-9][0-9]*$/
+    @topic.valid?
+    assert_equal ['global message'], @topic.errors[:title]
+  end
+
+  # validates_inclusion_of w/o mocha
+
+  def test_validates_inclusion_of_finds_custom_model_key_translation
+    I18n.backend.store_translations 'en', :activerecord => {:errors => {:models => {:topic => {:attributes => {:title => {:inclusion => 'custom message'}}}}}}
+    I18n.backend.store_translations 'en', :activerecord => {:errors => {:messages => {:inclusion => 'global message'}}}
+
+    Topic.validates_inclusion_of :title, :in => %w(a b c)
+    @topic.valid?
+    assert_equal ['custom message'], @topic.errors[:title]
+  end
+
+  def test_validates_inclusion_of_finds_global_default_translation
+    I18n.backend.store_translations 'en', :activerecord => {:errors => {:messages => {:inclusion => 'global message'}}}
+
+    Topic.validates_inclusion_of :title, :in => %w(a b c)
+    @topic.valid?
+    assert_equal ['global message'], @topic.errors[:title]
+  end
+
+  # validates_exclusion_of w/o mocha
+
+  def test_validates_exclusion_of_finds_custom_model_key_translation
+    I18n.backend.store_translations 'en', :activerecord => {:errors => {:models => {:topic => {:attributes => {:title => {:exclusion => 'custom message'}}}}}}
+    I18n.backend.store_translations 'en', :activerecord => {:errors => {:messages => {:exclusion => 'global message'}}}
+
+    Topic.validates_exclusion_of :title, :in => %w(a b c)
+    @topic.title = 'a'
+    @topic.valid?
+    assert_equal ['custom message'], @topic.errors[:title]
+  end
+
+  def test_validates_exclusion_of_finds_global_default_translation
+    I18n.backend.store_translations 'en', :activerecord => {:errors => {:messages => {:exclusion => 'global message'}}}
+
+    Topic.validates_exclusion_of :title, :in => %w(a b c)
+    @topic.title = 'a'
+    @topic.valid?
+    assert_equal ['global message'], @topic.errors[:title]
+  end
+
+  # validates_numericality_of without :only_integer w/o mocha
+
+  def test_validates_numericality_of_finds_custom_model_key_translation
+    I18n.backend.store_translations 'en', :activerecord => {:errors => {:models => {:topic => {:attributes => {:title => {:not_a_number => 'custom message'}}}}}}
+    I18n.backend.store_translations 'en', :activerecord => {:errors => {:messages => {:not_a_number => 'global message'}}}
+
+    Topic.validates_numericality_of :title
+    @topic.title = 'a'
+    @topic.valid?
+    assert_equal ['custom message'], @topic.errors[:title]
+  end
+
+  def test_validates_numericality_of_finds_global_default_translation
+    I18n.backend.store_translations 'en', :activerecord => {:errors => {:messages => {:not_a_number => 'global message'}}}
+
+    Topic.validates_numericality_of :title, :only_integer => true
+    @topic.title = 'a'
+    @topic.valid?
+    assert_equal ['global message'], @topic.errors[:title]
+  end
+
+  # validates_numericality_of with :only_integer w/o mocha
+
+  def test_validates_numericality_of_only_integer_finds_custom_model_key_translation
+    I18n.backend.store_translations 'en', :activerecord => {:errors => {:models => {:topic => {:attributes => {:title => {:not_a_number => 'custom message'}}}}}}
+    I18n.backend.store_translations 'en', :activerecord => {:errors => {:messages => {:not_a_number => 'global message'}}}
+
+    Topic.validates_numericality_of :title, :only_integer => true
+    @topic.title = 'a'
+    @topic.valid?
+    assert_equal ['custom message'], @topic.errors[:title]
+  end
+
+  def test_validates_numericality_of_only_integer_finds_global_default_translation
+    I18n.backend.store_translations 'en', :activerecord => {:errors => {:messages => {:not_a_number => 'global message'}}}
+
+    Topic.validates_numericality_of :title, :only_integer => true
+    @topic.title = 'a'
+    @topic.valid?
+    assert_equal ['global message'], @topic.errors[:title]
+  end
+
+  # validates_numericality_of :odd w/o mocha
+
+  def test_validates_numericality_of_odd_finds_custom_model_key_translation
+    I18n.backend.store_translations 'en', :activerecord => {:errors => {:models => {:topic => {:attributes => {:title => {:odd => 'custom message'}}}}}}
+    I18n.backend.store_translations 'en', :activerecord => {:errors => {:messages => {:odd => 'global message'}}}
+
+    Topic.validates_numericality_of :title, :only_integer => true, :odd => true
+    @topic.title = 0
+    @topic.valid?
+    assert_equal ['custom message'], @topic.errors[:title]
+  end
+
+  def test_validates_numericality_of_odd_finds_global_default_translation
+    I18n.backend.store_translations 'en', :activerecord => {:errors => {:messages => {:odd => 'global message'}}}
+
+    Topic.validates_numericality_of :title, :only_integer => true, :odd => true
+    @topic.title = 0
+    @topic.valid?
+    assert_equal ['global message'], @topic.errors[:title]
+  end
+
+  # validates_numericality_of :less_than w/o mocha
+
+  def test_validates_numericality_of_less_than_finds_custom_model_key_translation
+    I18n.backend.store_translations 'en', :activerecord => {:errors => {:models => {:topic => {:attributes => {:title => {:less_than => 'custom message'}}}}}}
+    I18n.backend.store_translations 'en', :activerecord => {:errors => {:messages => {:less_than => 'global message'}}}
+
+    Topic.validates_numericality_of :title, :only_integer => true, :less_than => 0
+    @topic.title = 1
+    @topic.valid?
+    assert_equal ['custom message'], @topic.errors[:title]
+  end
+
+  def test_validates_numericality_of_less_than_finds_global_default_translation
+    I18n.backend.store_translations 'en', :activerecord => {:errors => {:messages => {:less_than => 'global message'}}}
+
+    Topic.validates_numericality_of :title, :only_integer => true, :less_than => 0
+    @topic.title = 1
+    @topic.valid?
+    assert_equal ['global message'], @topic.errors[:title]
+  end
+
+  def test_validations_with_message_symbol_must_translate
+    I18n.backend.store_translations 'en', :activerecord => {:errors => {:messages => {:custom_error => "I am a custom error"}}}
+    Topic.validates_presence_of :title, :message => :custom_error
+    @topic.title = nil
+    @topic.valid?
+    assert_equal ["I am a custom error"], @topic.errors[:title]
+  end
+
+  def test_validates_with_message_symbol_must_translate_per_attribute
+    I18n.backend.store_translations 'en', :activerecord => {:errors => {:models => {:topic => {:attributes => {:title => {:custom_error => "I am a custom error"}}}}}}
+    Topic.validates_presence_of :title, :message => :custom_error
+    @topic.title = nil
+    @topic.valid?
+    assert_equal ["I am a custom error"], @topic.errors[:title]
+  end
+
+  def test_validates_with_message_symbol_must_translate_per_model
+    I18n.backend.store_translations 'en', :activerecord => {:errors => {:models => {:topic => {:custom_error => "I am a custom error"}}}}
+    Topic.validates_presence_of :title, :message => :custom_error
+    @topic.title = nil
+    @topic.valid?
+    assert_equal ["I am a custom error"], @topic.errors[:title]
+  end
+
+  def test_validates_with_message_string
+    Topic.validates_presence_of :title, :message => "I am a custom error"
+    @topic.title = nil
+    @topic.valid?
+    assert_equal ["I am a custom error"], @topic.errors[:title]
+  end
 end
diff --git a/activerecord/test/cases/validations_test.rb b/activerecord/test/cases/validations_test.rb
index ba2fb04d2f..27a42bcd03 100644
--- a/activerecord/test/cases/validations_test.rb
+++ b/activerecord/test/cases/validations_test.rb
@@ -129,4 +129,16 @@ class ValidationsTest < ActiveRecord::TestCase
     assert_equal 100, d.salary
     assert_equal "100,000", d.salary_before_type_cast
   end
+
+  def test_validates_length_with_globally_modified_error_message
+    ActiveSupport::Deprecation.silence do
+      ActiveRecord::Errors.default_error_messages[:too_short] = 'tu est trops petit hombre {{count}}'
+    end
+
+    Topic.validates_length_of :title, :minimum => 10
+    t = Topic.create(:title => 'too short')
+    assert !t.valid?
+
+    assert_equal ['tu est trops petit hombre 10'], t.errors[:title]
+  end
 end