Remove implicit constant lookup in serializers in favor active_model_serializer API.

test/serializer_test.rb

@@ -78,8 +78,13 @@ class SerializerTest < ActiveModel::TestCase
       { :title => @comment.read_attribute_for_serialization(:title) }
     end
 
-    def as_json(*)
-      { :comment => serializable_hash }
+    def as_json(options=nil)
+      options ||= {}
+      if options[:root] == false
+        serializable_hash
+      else
+        { :comment => serializable_hash }
+      end
     end
   end
 
@@ -189,65 +194,17 @@ class SerializerTest < ActiveModel::TestCase
     }, json)
   end
 
-  def test_implicit_serializer
-    author_serializer = Class.new(ActiveModel::Serializer) do
-      attributes :first_name
-    end
-
-    blog_serializer = Class.new(ActiveModel::Serializer) do
-      const_set(:AuthorSerializer, author_serializer)
-      has_one :author
-    end
-
-    user = User.new
-    blog = Blog.new
-    blog.author = user
-
-    json = blog_serializer.new(blog, user).as_json
-    assert_equal({
-      :author => {
-        :first_name => "Jose"
-      }
-    }, json)
-  end
-
-  def test_implicit_serializer_for_has_many
-    blog_with_posts = Class.new(Blog) do
-      attr_accessor :posts
-    end
-
-    blog_serializer = Class.new(ActiveModel::Serializer) do
-      const_set(:PostSerializer, PostSerializer)
-      has_many :posts
-    end
-
-    user = User.new
-    blog = blog_with_posts.new
-    blog.posts = [Post.new(:title => 'test')]
-
-    json = blog_serializer.new(blog, user).as_json
-    assert_equal({
-     :posts => [{
-       :title => "test", 
-       :body => nil, 
-       :comments => []
-     }]
-    }, json)
-  end
-
   def test_overridden_associations
     author_serializer = Class.new(ActiveModel::Serializer) do
       attributes :first_name
     end
 
     blog_serializer = Class.new(ActiveModel::Serializer) do
-      const_set(:PersonSerializer, author_serializer)
-
       def person
         object.author
       end
 
-      has_one :person
+      has_one :person, :serializer => author_serializer
     end
 
     user = User.new