Minor style improvements.

Author: beauby

test/adapter/json_api/resource_type_config_test.rb

@@ -28,8 +28,8 @@ def setup
           end
 
           def with_jsonapi_resource_type type
-            old_type = ActiveModel::Serializer.config[:jsonapi_resource_type]
-            ActiveModel::Serializer.config[:jsonapi_resource_type] = type
+            old_type = ActiveModel::Serializer.config.jsonapi_resource_type
+            ActiveModel::Serializer.config.jsonapi_resource_type = type
             yield
           ensure
             ActiveModel::Serializer.config.jsonapi_resource_type = old_type
@@ -38,7 +38,7 @@ def with_jsonapi_resource_type type
           def test_config_plural
             with_adapter :json_api do
               with_jsonapi_resource_type :plural do
-                hash = ActiveModel::SerializableResource.serialize(@comment).serializable_hash
+                hash = ActiveModel::SerializableResource.new(@comment).serializable_hash
                 assert_equal('comments', hash[:data][:type])
               end
             end
@@ -47,7 +47,7 @@ def test_config_plural
           def test_config_singular
             with_adapter :json_api do
               with_jsonapi_resource_type :singular do
-                hash = ActiveModel::SerializableResource.serialize(@comment).serializable_hash
+                hash = ActiveModel::SerializableResource.new(@comment).serializable_hash
                 assert_equal('comment', hash[:data][:type])
               end
             end