Update top-level link with PR rails-api#1247

update according rubocop rules

Author: leandrocp

docs/README.md

@@ -24,15 +24,6 @@ This is the documentation of ActiveModelSerializers, it's focused on the **0.10.
 - [Using ActiveModelSerializers Outside Of Controllers](howto/outside_controller_use.md)
 - [How to add top-level links](howto/add_top_level_links.md) (```JSON-API``` only)
 
-## Getting Help
-
-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).
-
-Thanks!
->>>>>>> Adds support for top-level links to JsonApi adapter
-
 ## Integrations
 
 | Integration | Supported ActiveModelSerializers versions |  Gem name and/or link

lib/active_model/serializer/adapter/json_api/links.rb

@@ -47,12 +47,11 @@ def render_array_using_implicit_serializer_and_meta
 
         def render_array_using_implicit_serializer_and_links
           with_adapter ActiveModel::Serializer::Adapter::JsonApi do
-
             @profiles = [
-              Profile.new({ name: 'Name 1', description: 'Description 1', comments: 'Comments 1' })
+              Profile.new(name: 'Name 1', description: 'Description 1', comments: 'Comments 1')
             ]
 
-            render json: @profiles, links: { self: "http://example.com/api/profiles/1" }
+            render json: @profiles, links: { self: 'http://example.com/api/profiles/1' }
           end
         end
 
@@ -272,15 +271,15 @@ def test_render_array_using_implicit_serializer_and_links
           data: [
             {
               id: assigns(:profiles).first.id.to_s,
-              type: "profiles",
+              type: 'profiles',
               attributes: {
-                name: "Name 1",
-                description: "Description 1"
+                name: 'Name 1',
+                description: 'Description 1'
               }
             }
           ],
           links: {
-            self: "http://example.com/api/profiles/1"
+            self: 'http://example.com/api/profiles/1'
           }
         }
 

test/action_controller/serialization_test.rb

@@ -43,6 +43,15 @@ def test_toplevel_links
             assert_equal(expected, hash[:links])
           end
 
+          def test_nil_toplevel_links
+            hash = ActiveModel::SerializableResource.new(
+              @post,
+              adapter: :json_api,
+              links: nil
+            ).serializable_hash
+            assert_equal(nil, hash[:links])
+          end
+
           def test_resource_links
             hash = serializable(@author, adapter: :json_api).serializable_hash
             expected = {