4 files changed, 35 insertions, 11 deletions
diff --git a/activemodel/test/cases/attribute_assignment_test.rb b/activemodel/test/cases/attribute_assignment_test.rb
index 3b01644dd1..64a85e01eb 100644
--- a/activemodel/test/cases/attribute_assignment_test.rb
+++ b/activemodel/test/cases/attribute_assignment_test.rb
@@ -58,8 +58,6 @@ class AttributeAssignmentTest < ActiveModel::TestCase
   end
 
   test "assign private attribute" do
-    rubinius_skip "https://github.com/rubinius/rubinius/issues/3328"
-
     model = Model.new
     assert_raises(ActiveModel::UnknownAttributeError) do
       model.assign_attributes(metadata: { a: 1 })
diff --git a/activemodel/test/cases/dirty_test.rb b/activemodel/test/cases/dirty_test.rb
index 66ed8a350a..d17a12ad12 100644
--- a/activemodel/test/cases/dirty_test.rb
+++ b/activemodel/test/cases/dirty_test.rb
@@ -137,6 +137,19 @@ class DirtyTest < ActiveModel::TestCase
     assert_equal [nil, "Jericho Cane"], @model.previous_changes['name']
   end
 
+  test "setting new attributes should not affect previous changes" do
+    @model.name = "Jericho Cane"
+    @model.save
+    @model.name = "DudeFella ManGuy"
+    assert_equal [nil, "Jericho Cane"], @model.name_previous_change
+  end
+
+  test "saving should preserve model's previous changed status" do
+    @model.name = "Jericho Cane"
+    @model.save
+    assert @model.name_previously_changed?
+  end
+
   test "previous value is preserved when changed after save" do
     assert_equal({}, @model.changed_attributes)
     @model.name = "Paul"
diff --git a/activemodel/test/cases/errors_test.rb b/activemodel/test/cases/errors_test.rb
index f781a0017f..d10c20caad 100644
--- a/activemodel/test/cases/errors_test.rb
+++ b/activemodel/test/cases/errors_test.rb
@@ -149,6 +149,12 @@ class ErrorsTest < ActiveModel::TestCase
     assert_equal ["cannot be blank"], person.errors[:name]
   end
 
+  test "add an error message on a specific attribute with a defined type" do
+    person = Person.new
+    person.errors.add(:name, :blank, message: "cannot be blank")
+    assert_equal ["cannot be blank"], person.errors[:name]
+  end
+
   test "add an error with a symbol" do
     person = Person.new
     person.errors.add(:name, :blank)
diff --git a/activemodel/test/cases/serialization_test.rb b/activemodel/test/cases/serialization_test.rb
index 4ae41aa19c..8d3165cd78 100644
--- a/activemodel/test/cases/serialization_test.rb
+++ b/activemodel/test/cases/serialization_test.rb
@@ -16,6 +16,14 @@ class SerializationTest < ActiveModel::TestCase
       instance_values.except("address", "friends")
     end
 
+    def method_missing(method_name, *args)
+      if method_name == :bar
+        'i_am_bar'
+      else
+        super
+      end
+    end
+
     def foo
       'i_am_foo'
     end
@@ -58,23 +66,22 @@ class SerializationTest < ActiveModel::TestCase
   end
 
   def test_method_serializable_hash_should_work_with_methods_option
-    expected = {"name"=>"David", "gender"=>"male", "foo"=>"i_am_foo", "email"=>"david@example.com"}
-    assert_equal expected, @user.serializable_hash(methods: [:foo])
+    expected = {"name"=>"David", "gender"=>"male", "foo"=>"i_am_foo", "bar"=>"i_am_bar", "email"=>"david@example.com"}
+    assert_equal expected, @user.serializable_hash(methods: [:foo, :bar])
   end
 
   def test_method_serializable_hash_should_work_with_only_and_methods
-    expected = {"foo"=>"i_am_foo"}
-    assert_equal expected, @user.serializable_hash(only: [], methods: [:foo])
+    expected = {"foo"=>"i_am_foo", "bar"=>"i_am_bar"}
+    assert_equal expected, @user.serializable_hash(only: [], methods: [:foo, :bar])
   end
 
   def test_method_serializable_hash_should_work_with_except_and_methods
-    expected = {"gender"=>"male", "foo"=>"i_am_foo"}
-    assert_equal expected, @user.serializable_hash(except: [:name, :email], methods: [:foo])
+    expected = {"gender"=>"male", "foo"=>"i_am_foo", "bar"=>"i_am_bar"}
+    assert_equal expected, @user.serializable_hash(except: [:name, :email], methods: [:foo, :bar])
   end
 
-  def test_should_not_call_methods_that_dont_respond
-    expected = {"name"=>"David", "gender"=>"male", "email"=>"david@example.com"}
-    assert_equal expected, @user.serializable_hash(methods: [:bar])
+  def test_should_raise_NoMethodError_for_non_existing_method
+    assert_raise(NoMethodError) { @user.serializable_hash(methods: [:nada]) }
   end
 
   def test_should_use_read_attribute_for_serialization