Serializers now inherit attributes and associations.

test/unit/active_model/serializer/attributes_test.rb

@@ -24,6 +24,18 @@ module ActiveModel
           'profile' => { name: 'Name 1', description: 'Description 1' }
         }, @profile_serializer.as_json)
       end
+
+      def test_attributes_inheritance
+        inherited_serializer_klass = Class.new(ProfileSerializer) do
+          attributes :comments
+        end
+        another_inherited_serializer_klass = Class.new(ProfileSerializer)
+
+        assert_equal([:name, :description, :comments],
+                     inherited_serializer_klass._attributes)
+        assert_equal([:name, :description],
+                     another_inherited_serializer_klass._attributes)
+      end
     end
   end
 end