Add some failing tests around has_many assocs...

..where no serializer is defined for the thing that is has_many'd

test/adapter/json/has_many_test.rb

@@ -17,6 +17,8 @@ module ActiveModel
             @second_comment.post = @post
             @blog = Blog.new(id: 1, name: "My Blog!!")
             @post.blog = @blog
+            @tag = Tag.new(id: 1, name: "#hash_tag")
+            @post.tags = [@tag]
 
             @serializer = PostSerializer.new(@post)
             @adapter = ActiveModel::Serializer::Adapter::Json.new(@serializer)
@@ -28,9 +30,14 @@ module ActiveModel
                            {id: 2, body: 'ZOMG ANOTHER COMMENT'}
                          ], @adapter.serializable_hash[:post][:comments])
           end
+
+          def test_has_many_with_no_serializer
+            serializer = PostWithTagsSerializer.new(@post)
+            adapter = ActiveModel::Serializer::Adapter::Json.new(serializer)
+            assert_includes(adapter.as_json, :tags)
+          end
         end
       end
     end
   end
 end
-

test/adapter/json_api/has_many_test.rb

@@ -27,6 +27,8 @@ module ActiveModel
             @blog.articles = [@post]
             @post.blog = @blog
             @post_without_comments.blog = nil
+            @tag = Tag.new(id: 1, name: "#hash_tag")
+            @post.tags = [@tag]
 
             @serializer = PostSerializer.new(@post)
             @adapter = ActiveModel::Serializer::Adapter::JsonApi.new(@serializer)
@@ -103,6 +105,12 @@ module ActiveModel
             }
             assert_equal expected, actual
           end
+
+          def test_has_many_with_no_serializer
+            serializer = PostWithTagsSerializer.new(@post)
+            adapter = ActiveModel::Serializer::Adapter::JsonApi.new(serializer)
+            assert_includes(adapter.serializable_hash, :tags)
+          end
         end
       end
     end

test/fixtures/poro.rb

@@ -76,6 +76,7 @@ Role     = Class.new(Model)
 User     = Class.new(Model)
 Location = Class.new(Model)
 Place    = Class.new(Model)
+Tag      = Class.new(Model)
 Comment  = Class.new(Model) do
   # Uses a custom non-time-based cache key
   def cache_key
@@ -224,6 +225,12 @@ PostPreviewSerializer = Class.new(ActiveModel::Serializer) do
   belongs_to :author, serializer: AuthorPreviewSerializer
 end
 
+PostWithTagsSerializer = Class.new(ActiveModel::Serializer) do
+  attributes :id
+
+  has_many :tags
+end
+
 Spam::UnrelatedLinkSerializer = Class.new(ActiveModel::Serializer) do
   attributes :id
 end

test/serializers/associations_test.rb

@@ -29,8 +29,10 @@ module ActiveModel
         @author.roles = []
         @blog = Blog.new({ name: 'AMS Blog' })
         @post = Post.new({ title: 'New Post', body: 'Body' })
+        @tag = Tag.new({name: '#hashtagged'})
         @comment = Comment.new({ id: 1, body: 'ZOMG A COMMENT' })
         @post.comments = [@comment]
+        @post.tags = [@tag]
         @post.blog = @blog
         @comment.post = @post
         @comment.author = nil
@@ -65,6 +67,12 @@ module ActiveModel
         end
       end
 
+      def test_has_many_with_no_serializer
+        PostWithTagsSerializer.new(@post).each_association do |name, serializer, options|
+          puts "The line above will crash this test"
+        end
+      end
+
       def test_serializer_options_are_passed_into_associations_serializers
         @post_serializer.each_association do |name, association|
           if name == :comments