11 files changed, 87 insertions, 27 deletions
diff --git a/activemodel/README.rdoc b/activemodel/README.rdoc
index 3262bf61ac..1b1fe2fa2b 100644
--- a/activemodel/README.rdoc
+++ b/activemodel/README.rdoc
@@ -1,7 +1,7 @@
 = Active Model -- model interfaces for Rails
 
 Active Model provides a known set of interfaces for usage in model classes.
-They allow for Action Pack helpers to interact with non-ActiveRecord models,
+They allow for Action Pack helpers to interact with non-Active Record models,
 for example. Active Model also helps building custom ORMs for use outside of
 the Rails framework.
 
@@ -11,7 +11,7 @@ code from Rails, or monkey patch entire helpers to make them handle objects
 that did not exactly conform to the Active Record interface. This would result
 in code duplication and fragile applications that broke on upgrades. Active
 Model solves this by defining an explicit API. You can read more about the
-API in ActiveModel::Lint::Tests.
+API in <tt>ActiveModel::Lint::Tests</tt>.
 
 Active Model provides a default module that implements the basic API required
 to integrate with Action Pack out of the box: <tt>ActiveModel::Model</tt>.
@@ -133,24 +133,6 @@ behavior out of the box:
 
   {Learn more}[link:classes/ActiveModel/Naming.html]
 
-* Observer support
-
-  ActiveModel::Observers allows your object to implement the Observer
-  pattern in a Rails App and take advantage of all the standard observer
-  functions.
-
-    class PersonObserver < ActiveModel::Observer
-      def after_create(person)
-        person.logger.info("New person added!")
-      end
-
-      def after_destroy(person)
-        person.logger.warn("Person with an id of #{person.id} was destroyed!")
-      end
-    end
-
-  {Learn more}[link:classes/ActiveModel/Observer.html]
-
 * Making objects serializable
 
   ActiveModel::Serialization provides a standard interface for your object
diff --git a/activemodel/lib/active_model/attribute_methods.rb b/activemodel/lib/active_model/attribute_methods.rb
index db5759ada9..6d11c0fbdc 100644
--- a/activemodel/lib/active_model/attribute_methods.rb
+++ b/activemodel/lib/active_model/attribute_methods.rb
@@ -436,7 +436,7 @@ module ActiveModel
     # attribute_missing is like method_missing, but for attributes. When method_missing is
     # called we check to see if there is a matching attribute method. If so, we call
     # attribute_missing to dispatch the attribute. This method can be overloaded to
-    # customise the behaviour.
+    # customize the behavior.
     def attribute_missing(match, *args, &block)
       __send__(match.target, match.attr_name, *args, &block)
     end
diff --git a/activemodel/lib/active_model/dirty.rb b/activemodel/lib/active_model/dirty.rb
index ecb7a9e9b1..6e67cd2285 100644
--- a/activemodel/lib/active_model/dirty.rb
+++ b/activemodel/lib/active_model/dirty.rb
@@ -119,7 +119,7 @@ module ActiveModel
     #   person.name = 'bob'
     #   person.changes # => { "name" => ["bill", "bob"] }
     def changes
-      HashWithIndifferentAccess[changed.map { |attr| [attr, attribute_change(attr)] }]
+      ActiveSupport::HashWithIndifferentAccess[changed.map { |attr| [attr, attribute_change(attr)] }]
     end
 
     # Returns a hash of attributes that were changed before the model was saved.
diff --git a/activemodel/lib/active_model/validations/clusivity.rb b/activemodel/lib/active_model/validations/clusivity.rb
index 3d7067fbcb..49df98d6c1 100644
--- a/activemodel/lib/active_model/validations/clusivity.rb
+++ b/activemodel/lib/active_model/validations/clusivity.rb
@@ -3,7 +3,7 @@ require 'active_support/core_ext/range'
 module ActiveModel
   module Validations
     module Clusivity #:nodoc:
-      ERROR_MESSAGE = "An object with the method #include? or a proc, lambda or symbol is required, " <<
+      ERROR_MESSAGE = "An object with the method #include? or a proc, lambda or symbol is required, " \
                       "and must be supplied as the :in (or :within) option of the configuration hash"
 
       def check_validity!
diff --git a/activemodel/lib/active_model/validations/numericality.rb b/activemodel/lib/active_model/validations/numericality.rb
index 744c196d30..085532c35b 100644
--- a/activemodel/lib/active_model/validations/numericality.rb
+++ b/activemodel/lib/active_model/validations/numericality.rb
@@ -17,9 +17,9 @@ module ActiveModel
       end
 
       def validate_each(record, attr_name, value)
-        before_type_cast = "#{attr_name}_before_type_cast"
+        before_type_cast = :"#{attr_name}_before_type_cast"
 
-        raw_value = record.send(before_type_cast) if record.respond_to?(before_type_cast.to_sym)
+        raw_value = record.send(before_type_cast) if record.respond_to?(before_type_cast)
         raw_value ||= value
 
         return if options[:allow_nil] && raw_value.nil?
diff --git a/activemodel/lib/active_model/validator.rb b/activemodel/lib/active_model/validator.rb
index d51f4d1936..f989b21140 100644
--- a/activemodel/lib/active_model/validator.rb
+++ b/activemodel/lib/active_model/validator.rb
@@ -103,7 +103,7 @@ module ActiveModel
     end
 
     # Accepts options that will be made available through the +options+ reader.
-    def initialize(options)
+    def initialize(options = {})
       @options = options.freeze
     end
 
diff --git a/activemodel/test/cases/conversion_test.rb b/activemodel/test/cases/conversion_test.rb
index d679ad41aa..a037666cbc 100644
--- a/activemodel/test/cases/conversion_test.rb
+++ b/activemodel/test/cases/conversion_test.rb
@@ -29,4 +29,8 @@ class ConversionTest < ActiveModel::TestCase
     assert_equal "helicopters/helicopter", Helicopter.new.to_partial_path,
       "ActiveModel::Conversion#to_partial_path caching should be class-specific"
   end
+
+  test "to_partial_path handles namespaced models" do
+    assert_equal "helicopter/comanches/comanche", Helicopter::Comanche.new.to_partial_path
+  end
 end
diff --git a/activemodel/test/cases/dirty_test.rb b/activemodel/test/cases/dirty_test.rb
index 0b9f9537e2..ba45089cca 100644
--- a/activemodel/test/cases/dirty_test.rb
+++ b/activemodel/test/cases/dirty_test.rb
@@ -46,7 +46,7 @@ class DirtyTest < ActiveModel::TestCase
     assert @model.name_changed?
   end
 
-  test "list of changed attributes" do
+  test "list of changed attribute keys" do
     assert_equal [], @model.changed
     @model.name = "Paul"
     assert_equal ['name'], @model.changed
@@ -106,6 +106,17 @@ class DirtyTest < ActiveModel::TestCase
     assert_equal [nil, "Jericho Cane"], @model.previous_changes['name']
   end
 
+  test "previous value is preserved when changed after save" do
+    assert_equal({}, @model.changed_attributes)
+    @model.name = "Paul"
+    assert_equal({ "name" => nil }, @model.changed_attributes)
+
+    @model.save
+
+    @model.name = "John"
+    assert_equal({ "name" => "Paul" }, @model.changed_attributes)
+  end
+
   test "changing the same attribute multiple times retains the correct original value" do
     @model.name = "Otto"
     @model.save
diff --git a/activemodel/test/cases/errors_test.rb b/activemodel/test/cases/errors_test.rb
index 1ffce1ae47..cc0c3f16d2 100644
--- a/activemodel/test/cases/errors_test.rb
+++ b/activemodel/test/cases/errors_test.rb
@@ -54,6 +54,59 @@ class ErrorsTest < ActiveModel::TestCase
     assert errors.has_key?(:foo), 'errors should have key :foo'
   end
 
+  test "should be able to clear the errors" do
+    person = Person.new
+    person.validate!
+
+    assert_equal 1, person.errors.count
+    person.errors.clear
+    assert person.errors.empty?
+  end
+
+  test "get returns the error by the provided key" do
+    errors = ActiveModel::Errors.new(self)
+    errors[:foo] = "omg"
+
+    assert_equal ["omg"], errors.get(:foo)
+  end
+
+  test "sets the error with the provided key" do
+    errors = ActiveModel::Errors.new(self)
+    errors.set(:foo, "omg")
+
+    assert_equal({ foo: "omg" }, errors.messages)
+  end
+
+  test "values returns an array of messages" do
+    errors = ActiveModel::Errors.new(self)
+    errors.set(:foo, "omg")
+    errors.set(:baz, "zomg")
+
+    assert_equal ["omg", "zomg"], errors.values
+  end
+
+  test "keys returns the error keys" do
+    errors = ActiveModel::Errors.new(self)
+    errors.set(:foo, "omg")
+    errors.set(:baz, "zomg")
+
+    assert_equal [:foo, :baz], errors.keys
+  end
+
+  test "as_json returns a json formatted representation of the errors hash" do
+    person = Person.new
+    person.validate!
+
+    assert_equal({ name: ["can not be nil"] }, person.errors.as_json)
+  end
+
+  test "as_json with :full_messages option" do
+    person = Person.new
+    person.validate!
+
+    assert_equal({ name: ["name can not be nil"] }, person.errors.as_json(full_messages: true))
+  end
+
   test "should return true if no errors" do
     person = Person.new
     person.errors[:foo]
diff --git a/activemodel/test/cases/model_test.rb b/activemodel/test/cases/model_test.rb
index d93fd96b88..588d8e661e 100644
--- a/activemodel/test/cases/model_test.rb
+++ b/activemodel/test/cases/model_test.rb
@@ -20,7 +20,13 @@ class ModelTest < ActiveModel::TestCase
   def test_initialize_with_nil_or_empty_hash_params_does_not_explode
     assert_nothing_raised do
       BasicModel.new()
+      BasicModel.new nil
       BasicModel.new({})
     end
   end
+
+  def test_persisted_is_always_false
+    object = BasicModel.new(:attr => "value")
+    assert object.persisted? == false
+  end
 end
diff --git a/activemodel/test/models/helicopter.rb b/activemodel/test/models/helicopter.rb
index a52b6fb4dd..933f3c463a 100644
--- a/activemodel/test/models/helicopter.rb
+++ b/activemodel/test/models/helicopter.rb
@@ -1,3 +1,7 @@
 class Helicopter
   include ActiveModel::Conversion
 end
+
+class Helicopter::Comanche
+  include ActiveModel::Conversion
+end