Adding Fragment Cache to AMS

It's an upgrade based on the new Cache implementation #693.
It allows to use the Rails conventions to cache
specific attributes or associations.
It's based on the Cache Composition implementation.

test/action_controller/serialization_test.rb

@@ -48,36 +48,79 @@ module ActionController
         end
 
         def render_object_with_cache_enabled
-          comment = Comment.new({ id: 1, body: 'ZOMG A COMMENT' })
-          author = Author.new(id: 1, name: 'Joao Moura.')
-          post = Post.new({ id: 1, title: 'New Post', blog:nil, body: 'Body', comments: [comment], author: author })
+          @comment = Comment.new({ id: 1, body: 'ZOMG A COMMENT' })
+          @author  = Author.new(id: 1, name: 'Joao Moura.')
+          @post    = Post.new({ id: 1, title: 'New Post', body: 'Body', comments: [@comment], author: @author })
 
-          generate_cached_serializer(post)
+          generate_cached_serializer(@post)
 
-          post.title = 'ZOMG a New Post'
-          render json: post
+          @post.title = 'ZOMG a New Post'
+          render json: @post
+        end
+
+        def update_and_render_object_with_cache_enabled
+          @post.updated_at = DateTime.now
+
+          generate_cached_serializer(@post)
+          render json: @post
         end
 
         def render_object_expired_with_cache_enabled
           comment = Comment.new({ id: 1, body: 'ZOMG A COMMENT' })
           author = Author.new(id: 1, name: 'Joao Moura.')
-          post = Post.new({ id: 1, title: 'New Post', blog:nil, body: 'Body', comments: [comment], author: author })
+          post = Post.new({ id: 1, title: 'New Post', body: 'Body', comments: [comment], author: author })
 
           generate_cached_serializer(post)
 
           post.title = 'ZOMG a New Post'
-          sleep 0.05
+          sleep 0.1
           render json: post
         end
 
         def render_changed_object_with_cache_enabled
           comment = Comment.new({ id: 1, body: 'ZOMG A COMMENT' })
           author = Author.new(id: 1, name: 'Joao Moura.')
-          post = Post.new({ id: 1, title: 'ZOMG a New Post', blog:nil, body: 'Body', comments: [comment], author: author })
+          post = Post.new({ id: 1, title: 'ZOMG a New Post', body: 'Body', comments: [comment], author: author })
 
           render json: post
         end
 
+        def render_fragment_changed_object_with_only_cache_enabled
+          author = Author.new(id: 1, name: 'Joao Moura.')
+          role = Role.new({ id: 42, name: 'ZOMG A ROLE', description: 'DESCRIPTION HERE', author: author })
+
+          generate_cached_serializer(role)
+          role.name = 'lol'
+          role.description = 'HUEHUEBRBR'
+
+          render json: role
+        end
+
+        def render_fragment_changed_object_with_except_cache_enabled
+          author = Author.new(id: 1, name: 'Joao Moura.')
+          bio = Bio.new({ id: 42, content: 'ZOMG A ROLE', rating: 5, author: author })
+
+          generate_cached_serializer(bio)
+          bio.content = 'lol'
+          bio.rating = 0
+
+          render json: bio
+        end
+
+        def render_fragment_changed_object_with_relationship
+          comment = Comment.new({ id: 1, body: 'ZOMG A COMMENT' })
+          author = Author.new(id: 1, name: 'Joao Moura.')
+          post = Post.new({ id: 1, title: 'New Post', body: 'Body', comments: [comment], author: author })
+          post2 = Post.new({ id: 1, title: 'New Post2', body: 'Body2', comments: [comment], author: author })
+          like = Like.new({ id: 1, post: post, time: 3.days.ago })
+
+          generate_cached_serializer(like)
+          like.post = post2
+          like.time = DateTime.now.to_s
+
+          render json: like
+        end
+
         private
         def generate_cached_serializer(obj)
           serializer_class = ActiveModel::Serializer.serializer_for(obj)
@@ -249,6 +292,74 @@ module ActionController
         assert_equal 'application/json', @response.content_type
         assert_equal expected.to_json, @response.body
       end
+
+      def test_render_with_fragment_only_cache_enable
+        ActionController::Base.cache_store.clear
+        get :render_fragment_changed_object_with_only_cache_enabled
+        response = JSON.parse(@response.body)
+
+        assert_equal 'application/json', @response.content_type
+        assert_equal 'ZOMG A ROLE', response["name"]
+        assert_equal 'HUEHUEBRBR', response["description"]
+      end
+
+      def test_render_with_fragment_except_cache_enable
+        ActionController::Base.cache_store.clear
+        get :render_fragment_changed_object_with_except_cache_enabled
+        response = JSON.parse(@response.body)
+
+        assert_equal 'application/json', @response.content_type
+        assert_equal 5, response["rating"]
+        assert_equal 'lol', response["content"]
+      end
+
+      def test_render_fragment_changed_object_with_relationship
+        ActionController::Base.cache_store.clear
+        get :render_fragment_changed_object_with_relationship
+        response = JSON.parse(@response.body)
+
+        expected_return = {
+          "post" => {
+            "id"=>1,
+            "title"=>"New Post",
+            "body"=>"Body"
+          },
+          "id"=>1,
+          "time"=>DateTime.now.to_s
+        }
+
+        assert_equal 'application/json', @response.content_type
+        assert_equal expected_return, response
+      end
+
+      def test_cache_expiration_on_update
+        ActionController::Base.cache_store.clear
+        get :render_object_with_cache_enabled
+
+        expected = {
+          id: 1,
+          title: 'ZOMG a New Post',
+          body: 'Body',
+          comments: [
+            {
+              id: 1,
+              body: 'ZOMG A COMMENT' }
+          ],
+          blog: {
+            id:999,
+            name: "Custom blog"
+          },
+          author: {
+            id: 1,
+            name: 'Joao Moura.'
+          }
+        }
+
+        get :update_and_render_object_with_cache_enabled
+
+        assert_equal 'application/json', @response.content_type
+        assert_equal expected.to_json, @response.body
+      end
     end
   end
 end