From 5f198667bec0cdbe85ffd61eb2e649171e2b6750 Mon Sep 17 00:00:00 2001
From: Guillermo Iguaran <guilleiguaran@gmail.com>
Date: Wed, 22 Oct 2014 03:55:17 -0300
Subject: [PATCH 1/8] Fix support for custom root in JSON-API adapter

---
 lib/active_model/serializer/adapter/json_api.rb |  2 +-
 test/action_controller/serialization_test.rb    | 17 +++++++++++++++++
 2 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/lib/active_model/serializer/adapter/json_api.rb b/lib/active_model/serializer/adapter/json_api.rb
index 71327b3c..0d93cac5 100644
--- a/lib/active_model/serializer/adapter/json_api.rb
+++ b/lib/active_model/serializer/adapter/json_api.rb
@@ -8,7 +8,7 @@ module ActiveModel
         end
 
         def serializable_hash(options = {})
-          @root = (options[:root] || serializer.json_key).to_s.pluralize.to_sym
+          @root = (options[:root] || serializer.json_key.to_s.pluralize).to_sym
           @hash = {}
 
           if serializer.respond_to?(:each)
diff --git a/test/action_controller/serialization_test.rb b/test/action_controller/serialization_test.rb
index 4103e273..fbbb48f9 100644
--- a/test/action_controller/serialization_test.rb
+++ b/test/action_controller/serialization_test.rb
@@ -24,6 +24,16 @@ module ActionController
           ActiveModel::Serializer.config.adapter = old_adapter
         end
 
+        def render_using_custom_root_in_adapter_with_a_default
+          old_adapter = ActiveModel::Serializer.config.adapter
+          # JSON-API adapter sets root by default
+          ActiveModel::Serializer.config.adapter = ActiveModel::Serializer::Adapter::JsonApi
+          @profile = Profile.new({ name: 'Name 1', description: 'Description 1', comments: 'Comments 1' })
+          render json: @profile, root: "profile"
+        ensure
+          ActiveModel::Serializer.config.adapter = old_adapter
+        end
+
         def render_array_using_implicit_serializer
           array = [
             Profile.new({ name: 'Name 1', description: 'Description 1', comments: 'Comments 1' }),
@@ -57,6 +67,13 @@ module ActionController
         assert_equal '{"profiles":{"name":"Name 1","description":"Description 1"}}', @response.body
       end
 
+      def test_render_using_custom_root_in_adapter_with_a_default
+        get :render_using_custom_root_in_adapter_with_a_default
+
+        assert_equal 'application/json', @response.content_type
+        assert_equal '{"profile":{"name":"Name 1","description":"Description 1"}}', @response.body
+      end
+
       def test_render_array_using_implicit_serializer
         get :render_array_using_implicit_serializer
         assert_equal 'application/json', @response.content_type

From f9b7c742359092e12447906af3d3800c43d0102e Mon Sep 17 00:00:00 2001
From: Edgars Jekabsons <jekabsons.edgars@gmail.com>
Date: Wed, 22 Oct 2014 15:30:44 +0300
Subject: [PATCH 2/8] Renamed embed test to have "test" suffix Fixed reference
 to association options

---
 lib/active_model/serializer/adapter/json_api.rb                 | 2 +-
 .../{has_many_embed_ids.rb => has_many_embed_ids_test.rb}       | 0
 2 files changed, 1 insertion(+), 1 deletion(-)
 rename test/adapter/json_api/{has_many_embed_ids.rb => has_many_embed_ids_test.rb} (100%)

diff --git a/lib/active_model/serializer/adapter/json_api.rb b/lib/active_model/serializer/adapter/json_api.rb
index 71327b3c..34ca48a5 100644
--- a/lib/active_model/serializer/adapter/json_api.rb
+++ b/lib/active_model/serializer/adapter/json_api.rb
@@ -18,7 +18,7 @@ module ActiveModel
 
             serializer.each_association do |name, association, opts|
               @hash[@root][:links] ||= {}
-              unless options[:embed] == :ids
+              unless opts[:embed] == :ids
                 @hash[:linked] ||= {}
               end
 
diff --git a/test/adapter/json_api/has_many_embed_ids.rb b/test/adapter/json_api/has_many_embed_ids_test.rb
similarity index 100%
rename from test/adapter/json_api/has_many_embed_ids.rb
rename to test/adapter/json_api/has_many_embed_ids_test.rb

From 19ac1398802ada24a9938dadc5cd1a36e4944308 Mon Sep 17 00:00:00 2001
From: Guillermo Iguaran <guilleiguaran@gmail.com>
Date: Thu, 30 Oct 2014 09:35:05 -0500
Subject: [PATCH 3/8] Handle correctly null associations

null belongs_to associations are now serialized as nil instead
of raise an error during serialization.
---
 lib/active_model/serializer.rb                  |  2 +-
 lib/active_model/serializer/adapter/json.rb     |  6 +++++-
 lib/active_model/serializer/adapter/json_api.rb | 14 +++++++++-----
 test/adapter/json/belongs_to_test.rb            | 11 +++++++++++
 test/adapter/json/collection_test.rb            |  7 +++++--
 test/adapter/json/has_many_test.rb              |  2 ++
 test/adapter/json_api/belongs_to_test.rb        | 12 ++++++++++++
 test/adapter/json_api/collection_test.rb        |  7 +++++--
 test/adapter/json_api/has_many_test.rb          |  2 ++
 test/adapter/json_test.rb                       |  2 ++
 test/fixtures/poro.rb                           |  1 +
 test/serializers/associations_test.rb           | 15 +++++++++------
 12 files changed, 64 insertions(+), 17 deletions(-)

diff --git a/lib/active_model/serializer.rb b/lib/active_model/serializer.rb
index 7050dc38..dbc2060d 100644
--- a/lib/active_model/serializer.rb
+++ b/lib/active_model/serializer.rb
@@ -133,7 +133,7 @@ module ActiveModel
       self.class._associations.dup.each do |name, options|
         association = object.send(name)
         serializer_class = ActiveModel::Serializer.serializer_for(association)
-        serializer = serializer_class.new(association)
+        serializer = serializer_class.new(association) if serializer_class
 
         if block_given?
           block.call(name, serializer, options[:options])
diff --git a/lib/active_model/serializer/adapter/json.rb b/lib/active_model/serializer/adapter/json.rb
index 3b568194..8ad1e41d 100644
--- a/lib/active_model/serializer/adapter/json.rb
+++ b/lib/active_model/serializer/adapter/json.rb
@@ -13,7 +13,11 @@ module ActiveModel
                 array_serializer = association
                 @result[name] = array_serializer.map { |item| item.attributes(opts) }
               else
-                @result[name] = association.attributes(options)
+                if association
+                  @result[name] = association.attributes(options)
+                else
+                  @result[name] = nil
+                end
               end
             end
           end
diff --git a/lib/active_model/serializer/adapter/json_api.rb b/lib/active_model/serializer/adapter/json_api.rb
index 3f0057a8..f5ff7128 100644
--- a/lib/active_model/serializer/adapter/json_api.rb
+++ b/lib/active_model/serializer/adapter/json_api.rb
@@ -44,13 +44,17 @@ module ActiveModel
         end
 
         def add_link(name, serializer, options)
-          @hash[@root][:links][name] = serializer.id.to_s
+          if serializer
+            @hash[@root][:links][name] = serializer.id.to_s
 
-          unless options[:embed] == :ids
-            plural_name = name.to_s.pluralize.to_sym
+            unless options[:embed] == :ids
+              plural_name = name.to_s.pluralize.to_sym
 
-            @hash[:linked][plural_name] ||= []
-            @hash[:linked][plural_name].push attributes_for_serializer(serializer, options)
+              @hash[:linked][plural_name] ||= []
+              @hash[:linked][plural_name].push attributes_for_serializer(serializer, options)
+            end
+          else
+            @hash[@root][:links][name] = nil
           end
         end
 
diff --git a/test/adapter/json/belongs_to_test.rb b/test/adapter/json/belongs_to_test.rb
index 498f1d98..663907de 100644
--- a/test/adapter/json/belongs_to_test.rb
+++ b/test/adapter/json/belongs_to_test.rb
@@ -7,9 +7,13 @@ module ActiveModel
         class BelongsToTest < Minitest::Test
           def setup
             @post = Post.new(id: 42, title: 'New Post', body: 'Body')
+            @anonymous_post = Post.new(id: 43, title: 'Hello!!', body: 'Hello, world!!')
             @comment = Comment.new(id: 1, body: 'ZOMG A COMMENT')
             @post.comments = [@comment]
+            @anonymous_post.comments = []
             @comment.post = @post
+            @post.author = @author
+            @anonymous_post.author = nil
 
             @serializer = CommentSerializer.new(@comment)
             @adapter = ActiveModel::Serializer::Adapter::Json.new(@serializer)
@@ -18,6 +22,13 @@ module ActiveModel
           def test_includes_post
             assert_equal({id: 42, title: 'New Post', body: 'Body'}, @adapter.serializable_hash[:post])
           end
+
+          def test_include_nil_author
+            serializer = PostSerializer.new(@anonymous_post)
+            adapter = ActiveModel::Serializer::Adapter::Json.new(serializer)
+
+            assert_equal({title: "Hello!!", body: "Hello, world!!", id: 43, comments: [], author: nil}, adapter.serializable_hash)
+          end
         end
       end
     end
diff --git a/test/adapter/json/collection_test.rb b/test/adapter/json/collection_test.rb
index 4d02f65a..51af5448 100644
--- a/test/adapter/json/collection_test.rb
+++ b/test/adapter/json/collection_test.rb
@@ -6,10 +6,13 @@ module ActiveModel
       class Json
         class Collection < Minitest::Test
           def setup
+            @author = Author.new(id: 1, name: 'Steve K.')
             @first_post = Post.new(id: 1, title: 'Hello!!', body: 'Hello, world!!')
             @second_post = Post.new(id: 2, title: 'New Post', body: 'Body')
             @first_post.comments = []
             @second_post.comments = []
+            @first_post.author = @author
+            @second_post.author = @author
 
             @serializer = ArraySerializer.new([@first_post, @second_post])
             @adapter = ActiveModel::Serializer::Adapter::Json.new(@serializer)
@@ -17,8 +20,8 @@ module ActiveModel
 
           def test_include_multiple_posts
             assert_equal([
-                           {title: "Hello!!", body: "Hello, world!!", id: 1, comments: []},
-                           {title: "New Post", body: "Body", id: 2, comments: []}
+                           {title: "Hello!!", body: "Hello, world!!", id: 1, comments: [], author: {id: 1, name: "Steve K."}},
+                           {title: "New Post", body: "Body", id: 2, comments: [], author: {id: 1, name: "Steve K."}}
                          ], @adapter.serializable_hash)
           end
         end
diff --git a/test/adapter/json/has_many_test.rb b/test/adapter/json/has_many_test.rb
index d1534e6b..77f672c7 100644
--- a/test/adapter/json/has_many_test.rb
+++ b/test/adapter/json/has_many_test.rb
@@ -6,10 +6,12 @@ module ActiveModel
       class Json
         class HasManyTestTest < Minitest::Test
           def setup
+            @author = Author.new(id: 1, name: 'Steve K.')
             @post = Post.new(title: 'New Post', body: 'Body')
             @first_comment = Comment.new(id: 1, body: 'ZOMG A COMMENT')
             @second_comment = Comment.new(id: 2, body: 'ZOMG ANOTHER COMMENT')
             @post.comments = [@first_comment, @second_comment]
+            @post.author = @author
             @first_comment.post = @post
             @second_comment.post = @post
 
diff --git a/test/adapter/json_api/belongs_to_test.rb b/test/adapter/json_api/belongs_to_test.rb
index 0a43e531..58a0f699 100644
--- a/test/adapter/json_api/belongs_to_test.rb
+++ b/test/adapter/json_api/belongs_to_test.rb
@@ -6,10 +6,15 @@ module ActiveModel
       class JsonApi
         class BelongsToTest < Minitest::Test
           def setup
+            @author = Author.new(id: 1, name: 'Steve K.')
             @post = Post.new(id: 42, title: 'New Post', body: 'Body')
+            @anonymous_post = Post.new(id: 43, title: 'Hello!!', body: 'Hello, world!!')
             @comment = Comment.new(id: 1, body: 'ZOMG A COMMENT')
             @post.comments = [@comment]
+            @anonymous_post.comments = []
             @comment.post = @post
+            @post.author = @author
+            @anonymous_post.author = nil
 
             @serializer = CommentSerializer.new(@comment)
             @adapter = ActiveModel::Serializer::Adapter::JsonApi.new(@serializer)
@@ -22,6 +27,13 @@ module ActiveModel
           def test_includes_linked_post
             assert_equal([{id: "42", title: 'New Post', body: 'Body'}], @adapter.serializable_hash[:linked][:posts])
           end
+
+          def test_include_nil_author
+            serializer = PostSerializer.new(@anonymous_post)
+            adapter = ActiveModel::Serializer::Adapter::JsonApi.new(serializer)
+
+            assert_equal({comments: [], author: nil}, adapter.serializable_hash[:posts][:links])
+          end
         end
       end
     end
diff --git a/test/adapter/json_api/collection_test.rb b/test/adapter/json_api/collection_test.rb
index 566581a8..5eaec7a5 100644
--- a/test/adapter/json_api/collection_test.rb
+++ b/test/adapter/json_api/collection_test.rb
@@ -6,10 +6,13 @@ module ActiveModel
       class JsonApi
         class Collection < Minitest::Test
           def setup
+            @author = Author.new(id: 1, name: 'Steve K.')
             @first_post = Post.new(id: 1, title: 'Hello!!', body: 'Hello, world!!')
             @second_post = Post.new(id: 2, title: 'New Post', body: 'Body')
             @first_post.comments = []
             @second_post.comments = []
+            @first_post.author = @author
+            @second_post.author = @author
 
             @serializer = ArraySerializer.new([@first_post, @second_post])
             @adapter = ActiveModel::Serializer::Adapter::JsonApi.new(@serializer)
@@ -17,8 +20,8 @@ module ActiveModel
 
           def test_include_multiple_posts
             assert_equal([
-                           {title: "Hello!!", body: "Hello, world!!", id: "1", links: {comments: []}},
-                           {title: "New Post", body: "Body", id: "2", links: {comments: []}}
+                           {title: "Hello!!", body: "Hello, world!!", id: "1", links: {comments: [], author: "1"}},
+                           {title: "New Post", body: "Body", id: "2", links: {comments: [], author: "1"}}
                          ], @adapter.serializable_hash[:posts])
           end
         end
diff --git a/test/adapter/json_api/has_many_test.rb b/test/adapter/json_api/has_many_test.rb
index f558c7d4..17c9c17d 100644
--- a/test/adapter/json_api/has_many_test.rb
+++ b/test/adapter/json_api/has_many_test.rb
@@ -6,12 +6,14 @@ module ActiveModel
       class JsonApi
         class HasManyTest < Minitest::Test
           def setup
+            @author = Author.new(id: 1, name: 'Steve K.')
             @post = Post.new(title: 'New Post', body: 'Body')
             @first_comment = Comment.new(id: 1, body: 'ZOMG A COMMENT')
             @second_comment = Comment.new(id: 2, body: 'ZOMG ANOTHER COMMENT')
             @post.comments = [@first_comment, @second_comment]
             @first_comment.post = @post
             @second_comment.post = @post
+            @post.author = @author
 
             @serializer = PostSerializer.new(@post)
             @adapter = ActiveModel::Serializer::Adapter::JsonApi.new(@serializer)
diff --git a/test/adapter/json_test.rb b/test/adapter/json_test.rb
index 1d2e35a6..fe573f7b 100644
--- a/test/adapter/json_test.rb
+++ b/test/adapter/json_test.rb
@@ -5,12 +5,14 @@ module ActiveModel
     class Adapter
       class JsonTest < Minitest::Test
         def setup
+          @author = Author.new(id: 1, name: 'Steve K.')
           @post = Post.new(title: 'New Post', body: 'Body')
           @first_comment = Comment.new(id: 1, body: 'ZOMG A COMMENT')
           @second_comment = Comment.new(id: 2, body: 'ZOMG ANOTHER COMMENT')
           @post.comments = [@first_comment, @second_comment]
           @first_comment.post = @post
           @second_comment.post = @post
+          @post.author = @author
 
           @serializer = PostSerializer.new(@post)
           @adapter = ActiveModel::Serializer::Adapter::Json.new(@serializer)
diff --git a/test/fixtures/poro.rb b/test/fixtures/poro.rb
index 2f4ffdbf..ce5f345a 100644
--- a/test/fixtures/poro.rb
+++ b/test/fixtures/poro.rb
@@ -43,6 +43,7 @@ PostSerializer = Class.new(ActiveModel::Serializer) do
   attributes :title, :body, :id
 
   has_many :comments
+  belongs_to :author
   url :comments
 end
 
diff --git a/test/serializers/associations_test.rb b/test/serializers/associations_test.rb
index 6d69b563..0891f365 100644
--- a/test/serializers/associations_test.rb
+++ b/test/serializers/associations_test.rb
@@ -2,7 +2,7 @@ require 'test_helper'
 
 module ActiveModel
   class Serializer
-    class AssocationsTest < Minitest::Test
+    class AssociationsTest < Minitest::Test
       class Model
         def initialize(hash={})
           @attributes = hash
@@ -25,20 +25,23 @@ module ActiveModel
 
 
       def setup
+        @author = Author.new(name: 'Steve K.')
         @post = Post.new({ title: 'New Post', body: 'Body' })
         @comment = Comment.new({ id: 1, body: 'ZOMG A COMMENT' })
         @post.comments = [@comment]
         @comment.post = @post
+        @post.author = @author
+        @author.posts = [@post]
 
-        @post_serializer = PostSerializer.new(@post)
+        @author_serializer = AuthorSerializer.new(@author)
         @comment_serializer = CommentSerializer.new(@comment)
       end
 
       def test_has_many
-        assert_equal({comments: {type: :has_many, options: {}}}, @post_serializer.class._associations)
-        @post_serializer.each_association do |name, serializer, options|
-          assert_equal(:comments, name)
-          assert_equal({}, options)
+        assert_equal({posts: {type: :has_many, options: {embed: :ids}}}, @author_serializer.class._associations)
+        @author_serializer.each_association do |name, serializer, options|
+          assert_equal(:posts, name)
+          assert_equal({embed: :ids}, options)
           assert_kind_of(ActiveModel::Serializer.config.array_serializer, serializer)
         end
       end

From 2d21a8e83fa537ad3b5ea0fd9e961c781ff85cbd Mon Sep 17 00:00:00 2001
From: Guillermo Iguaran <guilleiguaran@gmail.com>
Date: Fri, 31 Oct 2014 01:54:13 -0500
Subject: [PATCH 4/8] Add type when association name is different than objects
 type

---
 .../serializer/adapter/json_api.rb            | 23 ++++++++++++++++---
 test/adapter/json_api/belongs_to_test.rb      |  9 ++++++++
 test/adapter/json_api/has_many_test.rb        | 11 ++++++++-
 test/fixtures/poro.rb                         |  8 +++++++
 4 files changed, 47 insertions(+), 4 deletions(-)

diff --git a/lib/active_model/serializer/adapter/json_api.rb b/lib/active_model/serializer/adapter/json_api.rb
index f5ff7128..de0f3f83 100644
--- a/lib/active_model/serializer/adapter/json_api.rb
+++ b/lib/active_model/serializer/adapter/json_api.rb
@@ -34,8 +34,18 @@ module ActiveModel
         end
 
         def add_links(name, serializers, options)
-          @hash[@root][:links][name] ||= []
-          @hash[@root][:links][name] += serializers.map{|serializer| serializer.id.to_s }
+          if serializers.first
+            type = serializers.first.object.class.to_s.underscore.pluralize
+          end
+          if name.to_s == type || !type
+            @hash[@root][:links][name] ||= []
+            @hash[@root][:links][name] += serializers.map{|serializer| serializer.id.to_s }
+          else
+            @hash[@root][:links][name] ||= {}
+            @hash[@root][:links][name][:type] = type
+            @hash[@root][:links][name][:ids] ||= []
+            @hash[@root][:links][name][:ids] += serializers.map{|serializer| serializer.id.to_s }
+          end
 
           unless options[:embed] == :ids
             @hash[:linked][name] ||= []
@@ -45,7 +55,14 @@ module ActiveModel
 
         def add_link(name, serializer, options)
           if serializer
-            @hash[@root][:links][name] = serializer.id.to_s
+            type = serializer.object.class.to_s.underscore
+            if name.to_s == type || !type
+              @hash[@root][:links][name] = serializer.id.to_s
+            else
+              @hash[@root][:links][name] ||= {}
+              @hash[@root][:links][name][:type] = type
+              @hash[@root][:links][name][:id] = serializer.id.to_s
+            end
 
             unless options[:embed] == :ids
               plural_name = name.to_s.pluralize.to_sym
diff --git a/test/adapter/json_api/belongs_to_test.rb b/test/adapter/json_api/belongs_to_test.rb
index 58a0f699..0db303a6 100644
--- a/test/adapter/json_api/belongs_to_test.rb
+++ b/test/adapter/json_api/belongs_to_test.rb
@@ -15,6 +15,9 @@ module ActiveModel
             @comment.post = @post
             @post.author = @author
             @anonymous_post.author = nil
+            @blog = Blog.new(id: 1, name: "My Blog!!")
+            @blog.writer = @author
+            @blog.articles = [@post, @anonymous_post]
 
             @serializer = CommentSerializer.new(@comment)
             @adapter = ActiveModel::Serializer::Adapter::JsonApi.new(@serializer)
@@ -34,6 +37,12 @@ module ActiveModel
 
             assert_equal({comments: [], author: nil}, adapter.serializable_hash[:posts][:links])
           end
+
+          def test_include_type_for_association_when_is_different_than_name
+            serializer = BlogSerializer.new(@blog)
+            adapter = ActiveModel::Serializer::Adapter::JsonApi.new(serializer)
+            assert_equal({type: "author", id: "1"}, adapter.serializable_hash[:blogs][:links][:writer])
+          end
         end
       end
     end
diff --git a/test/adapter/json_api/has_many_test.rb b/test/adapter/json_api/has_many_test.rb
index 17c9c17d..2f74195f 100644
--- a/test/adapter/json_api/has_many_test.rb
+++ b/test/adapter/json_api/has_many_test.rb
@@ -7,13 +7,16 @@ module ActiveModel
         class HasManyTest < Minitest::Test
           def setup
             @author = Author.new(id: 1, name: 'Steve K.')
-            @post = Post.new(title: 'New Post', body: 'Body')
+            @post = Post.new(id: 1, title: 'New Post', body: 'Body')
             @first_comment = Comment.new(id: 1, body: 'ZOMG A COMMENT')
             @second_comment = Comment.new(id: 2, body: 'ZOMG ANOTHER COMMENT')
             @post.comments = [@first_comment, @second_comment]
             @first_comment.post = @post
             @second_comment.post = @post
             @post.author = @author
+            @blog = Blog.new(id: 1, name: "My Blog!!")
+            @blog.writer = @author
+            @blog.articles = [@post]
 
             @serializer = PostSerializer.new(@post)
             @adapter = ActiveModel::Serializer::Adapter::JsonApi.new(@serializer)
@@ -29,6 +32,12 @@ module ActiveModel
                            {id: "2", body: 'ZOMG ANOTHER COMMENT'}
                          ], @adapter.serializable_hash[:linked][:comments])
           end
+
+          def test_include_type_for_association_when_is_different_than_name
+            serializer = BlogSerializer.new(@blog)
+            adapter = ActiveModel::Serializer::Adapter::JsonApi.new(serializer)
+            assert_equal({type: "posts", ids: ["1"]}, adapter.serializable_hash[:blogs][:links][:articles])
+          end
         end
       end
     end
diff --git a/test/fixtures/poro.rb b/test/fixtures/poro.rb
index ce5f345a..77e3506f 100644
--- a/test/fixtures/poro.rb
+++ b/test/fixtures/poro.rb
@@ -38,6 +38,7 @@ end
 Post = Class.new(Model)
 Comment = Class.new(Model)
 Author = Class.new(Model)
+Blog = Class.new(Model)
 
 PostSerializer = Class.new(ActiveModel::Serializer) do
   attributes :title, :body, :id
@@ -58,3 +59,10 @@ AuthorSerializer = Class.new(ActiveModel::Serializer) do
 
   has_many :posts, embed: :ids
 end
+
+BlogSerializer = Class.new(ActiveModel::Serializer) do
+  attributes :id, :name
+
+  belongs_to :writer
+  has_many :articles
+end

From 3bba334cf875cd3d9f53c4d1f9673558f71139d6 Mon Sep 17 00:00:00 2001
From: Guillermo Iguaran <guilleiguaran@gmail.com>
Date: Fri, 31 Oct 2014 14:30:59 -0500
Subject: [PATCH 5/8] JSON-API: Don't include linked section if associations
 are empty

---
 lib/active_model/serializer/adapter/json_api.rb |  8 +++-----
 test/adapter/json_api/has_many_test.rb          | 10 ++++++++++
 2 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/lib/active_model/serializer/adapter/json_api.rb b/lib/active_model/serializer/adapter/json_api.rb
index de0f3f83..596d54c0 100644
--- a/lib/active_model/serializer/adapter/json_api.rb
+++ b/lib/active_model/serializer/adapter/json_api.rb
@@ -18,9 +18,6 @@ module ActiveModel
 
             serializer.each_association do |name, association, opts|
               @hash[@root][:links] ||= {}
-              unless opts[:embed] == :ids
-                @hash[:linked] ||= {}
-              end
 
               if association.respond_to?(:each)
                 add_links(name, association, opts)
@@ -47,7 +44,8 @@ module ActiveModel
             @hash[@root][:links][name][:ids] += serializers.map{|serializer| serializer.id.to_s }
           end
 
-          unless options[:embed] == :ids
+          unless options[:embed] == :ids || serializers.count == 0
+            @hash[:linked] ||= {}
             @hash[:linked][name] ||= []
             @hash[:linked][name] += serializers.map { |item| attributes_for_serializer(item, options) }
           end
@@ -66,7 +64,7 @@ module ActiveModel
 
             unless options[:embed] == :ids
               plural_name = name.to_s.pluralize.to_sym
-
+              @hash[:linked] ||= {}
               @hash[:linked][plural_name] ||= []
               @hash[:linked][plural_name].push attributes_for_serializer(serializer, options)
             end
diff --git a/test/adapter/json_api/has_many_test.rb b/test/adapter/json_api/has_many_test.rb
index 2f74195f..6bcd43ca 100644
--- a/test/adapter/json_api/has_many_test.rb
+++ b/test/adapter/json_api/has_many_test.rb
@@ -8,12 +8,15 @@ module ActiveModel
           def setup
             @author = Author.new(id: 1, name: 'Steve K.')
             @post = Post.new(id: 1, title: 'New Post', body: 'Body')
+            @post_without_comments = Post.new(id: 2, title: 'Second Post', body: 'Second')
             @first_comment = Comment.new(id: 1, body: 'ZOMG A COMMENT')
             @second_comment = Comment.new(id: 2, body: 'ZOMG ANOTHER COMMENT')
             @post.comments = [@first_comment, @second_comment]
+            @post_without_comments.comments = []
             @first_comment.post = @post
             @second_comment.post = @post
             @post.author = @author
+            @post_without_comments.author = nil
             @blog = Blog.new(id: 1, name: "My Blog!!")
             @blog.writer = @author
             @blog.articles = [@post]
@@ -33,6 +36,13 @@ module ActiveModel
                          ], @adapter.serializable_hash[:linked][:comments])
           end
 
+          def test_no_include_linked_if_comments_is_empty
+            serializer = PostSerializer.new(@post_without_comments)
+            adapter = ActiveModel::Serializer::Adapter::JsonApi.new(serializer)
+
+            assert_nil adapter.serializable_hash[:linked]
+          end
+
           def test_include_type_for_association_when_is_different_than_name
             serializer = BlogSerializer.new(@blog)
             adapter = ActiveModel::Serializer::Adapter::JsonApi.new(serializer)

From 3504c1a5d88296b69a241c7123bd7a45e14d600d Mon Sep 17 00:00:00 2001
From: Alexandre de Oliveira <chavedomundo@gmail.com>
Date: Sun, 2 Nov 2014 01:23:29 -0200
Subject: [PATCH 6/8] Fixes rbx gems bundling on TravisCI

---
 .travis.yml | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/.travis.yml b/.travis.yml
index d54edc2c..ad22ffe3 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -6,6 +6,8 @@ rvm:
   - jruby-19mode
   - rbx-2
   - ruby-head
+install:
+  - bundle install --retry=3
 env:
   - "RAILS_VERSION=3.2"
   - "RAILS_VERSION=4.0"

From d5bae0c2f0a1e5709b42bca4015617938eb72624 Mon Sep 17 00:00:00 2001
From: Gary Gordon <gfgordon@gmail.com>
Date: Thu, 23 Oct 2014 11:46:51 -0400
Subject: [PATCH 7/8] Include 'linked' member for json-api collections

The options passed to the render are partitioned into adapter options
and serializer options. 'include' and 'root' are sent to the adapter,
not sure what options would go directly to serializer, but leaving this
in until I understand that better.
---
 .gitignore                                    |   2 +-
 README.md                                     |  67 ++++++-----
 lib/action_controller/serialization.rb        |  10 +-
 lib/active_model/serializer/adapter.rb        |   1 +
 .../serializer/adapter/json_api.rb            |  47 +++++---
 .../action_controller/json_api_linked_test.rb | 104 ++++++++++++++++++
 test/adapter/json/belongs_to_test.rb          |   3 +-
 test/adapter/json_api/belongs_to_test.rb      |   3 +
 test/adapter/json_api/collection_test.rb      |   7 +-
 .../json_api/has_many_embed_ids_test.rb       |   2 +
 test/adapter/json_api/has_many_test.rb        |   4 +
 test/adapter/json_api/linked_test.rb          |  40 +++++++
 test/fixtures/poro.rb                         |   1 +
 test/serializers/associations_test.rb         |  15 ++-
 14 files changed, 250 insertions(+), 56 deletions(-)
 create mode 100644 test/action_controller/json_api_linked_test.rb
 create mode 100644 test/adapter/json_api/linked_test.rb

diff --git a/.gitignore b/.gitignore
index 838a74e0..1ecf6e4d 100644
--- a/.gitignore
+++ b/.gitignore
@@ -16,4 +16,4 @@ test/tmp
 test/version_tmp
 tmp
 *.swp
-.ruby-version
\ No newline at end of file
+.ruby-version
diff --git a/README.md b/README.md
index 77f1a108..4121dfe2 100644
--- a/README.md
+++ b/README.md
@@ -1,8 +1,8 @@
-# ActiveModel::Serializers 
- 
+# ActiveModel::Serializers
+
 [![Build Status](https://travis-ci.org/rails-api/active_model_serializers.svg)](https://travis-ci.org/rails-api/active_model_serializers)
 
-ActiveModel::Serializers brings convention over configuration to your JSON generation. 
+ActiveModel::Serializers brings convention over configuration to your JSON generation.
 
 AMS does this through two components: **serializers** and **adapters**. Serializers describe which attributes and relationships should be serialized. Adapters describe how attributes and relationships should be serialized.
 
@@ -32,7 +32,7 @@ serializers:
 ```ruby
 class PostSerializer < ActiveModel::Serializer
   attributes :title, :body
- 
+
   has_many :comments
 
   url :post
@@ -61,7 +61,7 @@ ActiveModel::Serializer.config.adapter = ActiveModel::Serializer::Adapter::HalAd
 ```
 
 or
- 
+
 ```ruby
 ActiveModel::Serializer.config.adapter = :hal
 ```
@@ -85,18 +85,27 @@ end
 In this case, Rails will look for a serializer named `PostSerializer`, and if
 it exists, use it to serialize the `Post`.
 
-## Installation 
- 
-Add this line to your application's Gemfile: 
+### Built in Adapters
 
-``` 
-gem 'active_model_serializers' 
+The `:json_api` adapter will include the associated resources in the `"linked"`
+member when the resource names are included in the `include` option.
+
+```ruby
+  render @posts, include: 'authors,comments'
 ```
- 
-And then execute: 
 
-``` 
-$ bundle 
+## Installation
+
+Add this line to your application's Gemfile:
+
+```
+gem 'active_model_serializers'
+```
+
+And then execute:
+
+```
+$ bundle
 ```
 
 ## Creating a Serializer
@@ -141,29 +150,27 @@ class CommentSerializer < ActiveModel::Serializer
 end
 ```
 
-The attribute names are a **whitelist** of attributes to be serialized. 
- 
+The attribute names are a **whitelist** of attributes to be serialized.
+
 The `has_many` and `belongs_to` declarations describe relationships between
-resources. By default, when you serialize a `Post`, you will
-get its `Comment`s as well.
+resources. By default, when you serialize a `Post`, you will get its `Comment`s
+as well.
 
 The `url` declaration describes which named routes to use while generating URLs
 for your JSON. Not every adapter will require URLs.
 
 ## Getting Help
 
-If you find a bug, please report an
-[Issue](https://github.com/rails-api/active_model_serializers/issues/new).
+If you find a bug, please report an [Issue](https://github.com/rails-api/active_model_serializers/issues/new).
 
-If you have a question, please [post to Stack
-Overflow](http://stackoverflow.com/questions/tagged/active-model-serializers).
+If you have a question, please [post to Stack Overflow](http://stackoverflow.com/questions/tagged/active-model-serializers).
 
 Thanks!
- 
-## Contributing 
- 
-1. Fork it ( https://github.com/rails-api/active_model_serializers/fork ) 
-2. Create your feature branch (`git checkout -b my-new-feature`) 
-3. Commit your changes (`git commit -am 'Add some feature'`) 
-4. Push to the branch (`git push origin my-new-feature`) 
-5. Create a new Pull Request 
+
+## Contributing
+
+1. Fork it ( https://github.com/rails-api/active_model_serializers/fork )
+2. Create your feature branch (`git checkout -b my-new-feature`)
+3. Commit your changes (`git commit -am 'Add some feature'`)
+4. Push to the branch (`git push origin my-new-feature`)
+5. Create a new Pull Request
diff --git a/lib/action_controller/serialization.rb b/lib/action_controller/serialization.rb
index f26f0112..2b460cb4 100644
--- a/lib/action_controller/serialization.rb
+++ b/lib/action_controller/serialization.rb
@@ -6,15 +6,18 @@ module ActionController
 
     include ActionController::Renderers
 
+    ADAPTER_OPTION_KEYS = [:include, :root]
+
     [:_render_option_json, :_render_with_renderer_json].each do |renderer_method|
       define_method renderer_method do |resource, options|
         serializer = ActiveModel::Serializer.serializer_for(resource)
 
         if serializer
+          adapter_opts, serializer_opts =
+            options.partition { |k, _| ADAPTER_OPTION_KEYS.include? k }
           # omg hax
-          object = serializer.new(resource, options)
-          adapter = ActiveModel::Serializer.adapter.new(object)
-
+          object = serializer.new(resource, Hash[serializer_opts])
+          adapter = ActiveModel::Serializer.adapter.new(object, Hash[adapter_opts])
           super(adapter, options)
         else
           super(resource, options)
@@ -23,4 +26,3 @@ module ActionController
     end
   end
 end
-
diff --git a/lib/active_model/serializer/adapter.rb b/lib/active_model/serializer/adapter.rb
index f0a82573..864adbb4 100644
--- a/lib/active_model/serializer/adapter.rb
+++ b/lib/active_model/serializer/adapter.rb
@@ -10,6 +10,7 @@ module ActiveModel
 
       def initialize(serializer, options = {})
         @serializer = serializer
+        @options = options
       end
 
       def serializable_hash(options = {})
diff --git a/lib/active_model/serializer/adapter/json_api.rb b/lib/active_model/serializer/adapter/json_api.rb
index 596d54c0..693ec316 100644
--- a/lib/active_model/serializer/adapter/json_api.rb
+++ b/lib/active_model/serializer/adapter/json_api.rb
@@ -5,16 +5,19 @@ module ActiveModel
         def initialize(serializer, options = {})
           super
           serializer.root = true
+          @hash = {}
+          @top = @options.fetch(:top) { @hash }
         end
 
         def serializable_hash(options = {})
-          @root = (options[:root] || serializer.json_key.to_s.pluralize).to_sym
-          @hash = {}
+          @root = (@options[:root] || serializer.json_key.to_s.pluralize).to_sym
 
           if serializer.respond_to?(:each)
-            @hash[@root] = serializer.map{|s| self.class.new(s).serializable_hash[@root] }
+            @hash[@root] = serializer.map do |s|
+              self.class.new(s, @options.merge(top: @top)).serializable_hash[@root]
+            end
           else
-            @hash[@root] = attributes_for_serializer(serializer, {})
+            @hash[@root] = attributes_for_serializer(serializer, @options)
 
             serializer.each_association do |name, association, opts|
               @hash[@root][:links] ||= {}
@@ -44,10 +47,10 @@ module ActiveModel
             @hash[@root][:links][name][:ids] += serializers.map{|serializer| serializer.id.to_s }
           end
 
-          unless options[:embed] == :ids || serializers.count == 0
-            @hash[:linked] ||= {}
-            @hash[:linked][name] ||= []
-            @hash[:linked][name] += serializers.map { |item| attributes_for_serializer(item, options) }
+          unless serializers.none? || @options[:embed] == :ids
+            serializers.each do |serializer|
+              add_linked(name, serializer)
+            end
           end
         end
 
@@ -62,17 +65,31 @@ module ActiveModel
               @hash[@root][:links][name][:id] = serializer.id.to_s
             end
 
-            unless options[:embed] == :ids
-              plural_name = name.to_s.pluralize.to_sym
-              @hash[:linked] ||= {}
-              @hash[:linked][plural_name] ||= []
-              @hash[:linked][plural_name].push attributes_for_serializer(serializer, options)
+            unless @options[:embed] == :ids
+              add_linked(name, serializer)
             end
           else
             @hash[@root][:links][name] = nil
           end
         end
 
+        def add_linked(resource, serializer, parent = nil)
+          resource_path = [parent, resource].compact.join('.')
+          if include_assoc? resource_path
+            plural_name = resource.to_s.pluralize.to_sym
+            attrs = attributes_for_serializer(serializer, @options)
+            @top[:linked] ||= {}
+            @top[:linked][plural_name] ||= []
+            @top[:linked][plural_name].push attrs unless @top[:linked][plural_name].include? attrs
+          end
+
+          unless serializer.respond_to?(:each)
+            serializer.each_association do |name, association, opts|
+              add_linked(name, association, resource) if association
+            end
+          end
+        end
+
         private
 
         def attributes_for_serializer(serializer, options)
@@ -80,6 +97,10 @@ module ActiveModel
           attributes[:id] = attributes[:id].to_s if attributes[:id]
           attributes
         end
+
+        def include_assoc? assoc
+          @options[:include] && @options[:include].split(',').include?(assoc.to_s)
+        end
       end
     end
   end
diff --git a/test/action_controller/json_api_linked_test.rb b/test/action_controller/json_api_linked_test.rb
new file mode 100644
index 00000000..f02e90e2
--- /dev/null
+++ b/test/action_controller/json_api_linked_test.rb
@@ -0,0 +1,104 @@
+require 'test_helper'
+
+module ActionController
+  module Serialization
+    class JsonApiLinkedTest < ActionController::TestCase
+      class MyController < ActionController::Base
+        def setup_post
+          @author = Author.new(id: 1, name: 'Steve K.')
+          @author.posts = []
+          @author2 = Author.new(id: 2, name: 'Anonymous')
+          @author2.posts = []
+          @post = Post.new(id: 1, title: 'New Post', body: 'Body')
+          @first_comment = Comment.new(id: 1, body: 'ZOMG A COMMENT')
+          @second_comment = Comment.new(id: 2, body: 'ZOMG ANOTHER COMMENT')
+          @post.comments = [@first_comment, @second_comment]
+          @post.author = @author
+          @first_comment.post = @post
+          @first_comment.author = @author2
+          @second_comment.post = @post
+          @second_comment.author = nil
+        end
+
+        def with_json_api_adapter
+          old_adapter = ActiveModel::Serializer.config.adapter
+          ActiveModel::Serializer.config.adapter = :json_api
+          yield
+        ensure
+          ActiveModel::Serializer.config.adapter = old_adapter
+        end
+
+        def render_resource_without_include
+          with_json_api_adapter do
+            setup_post
+            render json: @post
+          end
+        end
+
+        def render_resource_with_include
+          with_json_api_adapter do
+            setup_post
+            render json: @post, include: 'author'
+          end
+        end
+
+        def render_resource_with_nested_include
+          with_json_api_adapter do
+            setup_post
+            render json: @post, include: 'comments.author'
+          end
+        end
+
+        def render_collection_without_include
+          with_json_api_adapter do
+            setup_post
+            render json: [@post]
+          end
+        end
+
+        def render_collection_with_include
+          with_json_api_adapter do
+            setup_post
+            render json: [@post], include: 'author,comments'
+          end
+        end
+      end
+
+      tests MyController
+
+      def test_render_resource_without_include
+        get :render_resource_without_include
+        response = JSON.parse(@response.body)
+        refute response.key? 'linked'
+      end
+
+      def test_render_resource_with_include
+        get :render_resource_with_include
+        response = JSON.parse(@response.body)
+        assert response.key? 'linked'
+        assert_equal 1, response['linked']['authors'].size
+        assert_equal 'Steve K.', response['linked']['authors'].first['name']
+      end
+
+      def test_render_resource_with_nested_include
+        get :render_resource_with_nested_include
+        response = JSON.parse(@response.body)
+        assert response.key? 'linked'
+        assert_equal 1, response['linked']['authors'].size
+        assert_equal 'Anonymous', response['linked']['authors'].first['name']
+      end
+
+      def test_render_collection_without_include
+        get :render_collection_without_include
+        response = JSON.parse(@response.body)
+        refute response.key? 'linked'
+      end
+
+      def test_render_collection_with_include
+        get :render_collection_with_include
+        response = JSON.parse(@response.body)
+        assert response.key? 'linked'
+      end
+    end
+  end
+end
diff --git a/test/adapter/json/belongs_to_test.rb b/test/adapter/json/belongs_to_test.rb
index 663907de..ea118647 100644
--- a/test/adapter/json/belongs_to_test.rb
+++ b/test/adapter/json/belongs_to_test.rb
@@ -11,8 +11,9 @@ module ActiveModel
             @comment = Comment.new(id: 1, body: 'ZOMG A COMMENT')
             @post.comments = [@comment]
             @anonymous_post.comments = []
-            @comment.post = @post
             @post.author = @author
+            @comment.post = @post
+            @comment.author = nil
             @anonymous_post.author = nil
 
             @serializer = CommentSerializer.new(@comment)
diff --git a/test/adapter/json_api/belongs_to_test.rb b/test/adapter/json_api/belongs_to_test.rb
index 0db303a6..e25a71d8 100644
--- a/test/adapter/json_api/belongs_to_test.rb
+++ b/test/adapter/json_api/belongs_to_test.rb
@@ -13,11 +13,13 @@ module ActiveModel
             @post.comments = [@comment]
             @anonymous_post.comments = []
             @comment.post = @post
+            @comment.author = nil
             @post.author = @author
             @anonymous_post.author = nil
             @blog = Blog.new(id: 1, name: "My Blog!!")
             @blog.writer = @author
             @blog.articles = [@post, @anonymous_post]
+            @author.posts = []
 
             @serializer = CommentSerializer.new(@comment)
             @adapter = ActiveModel::Serializer::Adapter::JsonApi.new(@serializer)
@@ -28,6 +30,7 @@ module ActiveModel
           end
 
           def test_includes_linked_post
+            @adapter = ActiveModel::Serializer::Adapter::JsonApi.new(@serializer, include: 'post')
             assert_equal([{id: "42", title: 'New Post', body: 'Body'}], @adapter.serializable_hash[:linked][:posts])
           end
 
diff --git a/test/adapter/json_api/collection_test.rb b/test/adapter/json_api/collection_test.rb
index 5eaec7a5..922103ea 100644
--- a/test/adapter/json_api/collection_test.rb
+++ b/test/adapter/json_api/collection_test.rb
@@ -4,7 +4,7 @@ module ActiveModel
   class Serializer
     class Adapter
       class JsonApi
-        class Collection < Minitest::Test
+        class CollectionTest < Minitest::Test
           def setup
             @author = Author.new(id: 1, name: 'Steve K.')
             @first_post = Post.new(id: 1, title: 'Hello!!', body: 'Hello, world!!')
@@ -13,6 +13,7 @@ module ActiveModel
             @second_post.comments = []
             @first_post.author = @author
             @second_post.author = @author
+            @author.posts = [@first_post, @second_post]
 
             @serializer = ArraySerializer.new([@first_post, @second_post])
             @adapter = ActiveModel::Serializer::Adapter::JsonApi.new(@serializer)
@@ -20,8 +21,8 @@ module ActiveModel
 
           def test_include_multiple_posts
             assert_equal([
-                           {title: "Hello!!", body: "Hello, world!!", id: "1", links: {comments: [], author: "1"}},
-                           {title: "New Post", body: "Body", id: "2", links: {comments: [], author: "1"}}
+                           { title: "Hello!!", body: "Hello, world!!", id: "1", links: { comments: [], author: "1" } },
+                           { title: "New Post", body: "Body", id: "2", links: { comments: [], author: "1" } }
                          ], @adapter.serializable_hash[:posts])
           end
         end
diff --git a/test/adapter/json_api/has_many_embed_ids_test.rb b/test/adapter/json_api/has_many_embed_ids_test.rb
index d5c448b5..4690e3c6 100644
--- a/test/adapter/json_api/has_many_embed_ids_test.rb
+++ b/test/adapter/json_api/has_many_embed_ids_test.rb
@@ -12,6 +12,8 @@ module ActiveModel
             @author.posts = [@first_post, @second_post]
             @first_post.author = @author
             @second_post.author = @author
+            @first_post.comments = []
+            @second_post.comments = []
 
             @serializer = AuthorSerializer.new(@author)
             @adapter = ActiveModel::Serializer::Adapter::JsonApi.new(@serializer)
diff --git a/test/adapter/json_api/has_many_test.rb b/test/adapter/json_api/has_many_test.rb
index 6bcd43ca..975c5b63 100644
--- a/test/adapter/json_api/has_many_test.rb
+++ b/test/adapter/json_api/has_many_test.rb
@@ -7,10 +7,13 @@ module ActiveModel
         class HasManyTest < Minitest::Test
           def setup
             @author = Author.new(id: 1, name: 'Steve K.')
+            @author.posts = []
             @post = Post.new(id: 1, title: 'New Post', body: 'Body')
             @post_without_comments = Post.new(id: 2, title: 'Second Post', body: 'Second')
             @first_comment = Comment.new(id: 1, body: 'ZOMG A COMMENT')
+            @first_comment.author = nil
             @second_comment = Comment.new(id: 2, body: 'ZOMG ANOTHER COMMENT')
+            @second_comment.author = nil
             @post.comments = [@first_comment, @second_comment]
             @post_without_comments.comments = []
             @first_comment.post = @post
@@ -30,6 +33,7 @@ module ActiveModel
           end
 
           def test_includes_linked_comments
+            @adapter = ActiveModel::Serializer::Adapter::JsonApi.new(@serializer, include: 'comments')
             assert_equal([
                            {id: "1", body: 'ZOMG A COMMENT'},
                            {id: "2", body: 'ZOMG ANOTHER COMMENT'}
diff --git a/test/adapter/json_api/linked_test.rb b/test/adapter/json_api/linked_test.rb
new file mode 100644
index 00000000..160d3daa
--- /dev/null
+++ b/test/adapter/json_api/linked_test.rb
@@ -0,0 +1,40 @@
+require 'test_helper'
+
+module ActiveModel
+  class Serializer
+    class Adapter
+      class JsonApi
+        class LinkedTest < Minitest::Test
+          def setup
+            @author = Author.new(id: 1, name: 'Steve K.')
+            @first_post = Post.new(id: 1, title: 'Hello!!', body: 'Hello, world!!')
+            @second_post = Post.new(id: 2, title: 'New Post', body: 'Body')
+            @first_post.comments = []
+            @second_post.comments = []
+            @first_post.author = @author
+            @second_post.author = @author
+            @author.posts = [@first_post, @second_post]
+
+            @serializer = ArraySerializer.new([@first_post, @second_post])
+            @adapter = ActiveModel::Serializer::Adapter::JsonApi.new(@serializer, include: 'author,comments')
+          end
+
+          def test_include_multiple_posts_and_linked
+            @first_comment = Comment.new(id: 1, body: 'ZOMG A COMMENT')
+            @second_comment = Comment.new(id: 2, body: 'ZOMG ANOTHER COMMENT')
+            @first_post.comments = [@first_comment, @second_comment]
+            @first_comment.post = @first_post
+            @first_comment.author = nil
+            @second_comment.post = @first_post
+            @second_comment.author = nil
+            assert_equal([
+                           { title: "Hello!!", body: "Hello, world!!", id: "1", links: { comments: ['1', '2'], author: "1" } },
+                           { title: "New Post", body: "Body", id: "2", links: { comments: [], :author => "1" } }
+                         ], @adapter.serializable_hash[:posts])
+            assert_equal({ :comments => [{ :id => "1", :body => "ZOMG A COMMENT" }, { :id => "2", :body => "ZOMG ANOTHER COMMENT" }], :authors => [{ :id => "1", :name => "Steve K." }] }, @adapter.serializable_hash[:linked])
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/test/fixtures/poro.rb b/test/fixtures/poro.rb
index 77e3506f..7d8d57b4 100644
--- a/test/fixtures/poro.rb
+++ b/test/fixtures/poro.rb
@@ -52,6 +52,7 @@ CommentSerializer = Class.new(ActiveModel::Serializer) do
   attributes :id, :body
 
   belongs_to :post
+  belongs_to :author
 end
 
 AuthorSerializer = Class.new(ActiveModel::Serializer) do
diff --git a/test/serializers/associations_test.rb b/test/serializers/associations_test.rb
index 0891f365..99162acc 100644
--- a/test/serializers/associations_test.rb
+++ b/test/serializers/associations_test.rb
@@ -30,6 +30,7 @@ module ActiveModel
         @comment = Comment.new({ id: 1, body: 'ZOMG A COMMENT' })
         @post.comments = [@comment]
         @comment.post = @post
+        @comment.author = nil
         @post.author = @author
         @author.posts = [@post]
 
@@ -47,11 +48,17 @@ module ActiveModel
       end
 
       def test_has_one
-        assert_equal({post: {type: :belongs_to, options: {}}}, @comment_serializer.class._associations)
+        assert_equal({post: {type: :belongs_to, options: {}}, :author=>{:type=>:belongs_to, :options=>{}}}, @comment_serializer.class._associations)
         @comment_serializer.each_association do |name, serializer, options|
-          assert_equal(:post, name)
-          assert_equal({}, options)
-          assert_kind_of(PostSerializer, serializer)
+          if name == :post
+            assert_equal({}, options)
+            assert_kind_of(PostSerializer, serializer)
+          elsif name == :author
+            assert_equal({}, options)
+            assert_nil serializer
+          else
+            flunk "Unknown association: #{name}"
+          end
         end
       end
     end

From f5411f045f87b4c45177d812714cdf7b6827f0b5 Mon Sep 17 00:00:00 2001
From: Guillermo Iguaran <guilleiguaran@gmail.com>
Date: Mon, 3 Nov 2014 17:38:58 -0500
Subject: [PATCH 8/8] Define as_json instead of to_json

---
 lib/active_model/serializer/adapter.rb | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/lib/active_model/serializer/adapter.rb b/lib/active_model/serializer/adapter.rb
index f0a82573..3a883dad 100644
--- a/lib/active_model/serializer/adapter.rb
+++ b/lib/active_model/serializer/adapter.rb
@@ -16,8 +16,8 @@ module ActiveModel
         raise NotImplementedError, 'This is an abstract method. Should be implemented at the concrete adapter.'
       end
 
-      def to_json(options = {})
-        serializable_hash(options).to_json
+      def as_json(options = {})
+        serializable_hash(options)
       end
     end
   end