Fix API notes endpoint when posting only emoji

doc/api/notes.md

@@ -78,7 +78,8 @@ Parameters:
 ### Create new issue note
-Creates a new note to a single project issue.
+Creates a new note to a single project issue. If you create a note where the body
+only contains an Award Emoji, you'll receive this object back.
 ```
 POST /projects/:id/issues/:issue_id/notes
@@ -204,6 +205,7 @@ Parameters:
 ### Create new snippet note
 Creates a new note for a single snippet. Snippet notes are comments users can post to a snippet.
+If you create a note where the body only contains an Award Emoji, you'll receive this object back.
 ```
 POST /projects/:id/snippets/:snippet_id/notes
@@ -332,6 +334,8 @@ Parameters:
 ### Create new merge request note
 Creates a new note for a single merge request.
+If you create a note where the body only contains an Award Emoji, you'll receive
+this object back.
 ```
 POST /projects/:id/merge_requests/:merge_request_id/notes

lib/api/notes.rb

@@ -83,12 +83,12 @@ module API
             opts[:created_at] = params[:created_at]
           end
-          @note = ::Notes::CreateService.new(user_project, current_user, opts).execute
-          if @note.valid?
-            present @note, with: Entities::Note
+          note = ::Notes::CreateService.new(user_project, current_user, opts).execute
+          if note.valid?
+            present note, with: Entities::const_get(note.class.name)
           else
-            not_found!("Note #{@note.errors.messages}")
+            not_found!("Note #{note.errors.messages}")
           end
         end

spec/requests/api/notes_spec.rb

@@ -220,6 +220,15 @@ describe API::API, api: true  do
           expect(Time.parse(json_response['created_at'])).to be_within(1.second).of(creation_time)
         end
       end
+
+      context 'when the user is posting an award emoji' do
+        it 'returns an award emoji' do
+          post api("/projects/#{project.id}/issues/#{issue.id}/notes", user), body: ':+1:'
+
+          expect(response).to have_http_status(201)
+          expect(json_response['awardable_id']).to eq issue.id
+        end
+      end
     end
     context "when noteable is a Snippet" do