Use serialization for project boards

- Add serializers and Grape::Entity
- Replace to_json
- Add specs

app/controllers/concerns/boards_actions.rb

@@ -35,4 +35,12 @@ module BoardsActions
       boards.find(params[:id])
     end
   end
+
+  def serializer
+    BoardSerializer.new(current_user: current_user)
+  end
+
+  def serialize_as_json(resource)
+    serializer.represent(resource, serializer: 'board', include_full_project_path: board.group_board?)
+  end
 end

app/controllers/concerns/boards_responses.rb

@@ -69,7 +69,7 @@ module BoardsResponses
   end
 
   def serialize_as_json(resource)
-    resource.as_json(only: [:id])
+    serializer.represent(resource)
   end
 
   def respond_with(resource)
@@ -80,4 +80,8 @@ module BoardsResponses
       end
     end
   end
+
+  def serializer
+    BoardSerializer.new
+  end
 end

app/serializers/board_serializer.rb

+# frozen_string_literal: true
+
+class BoardSerializer < BaseSerializer
+  entity BoardSimpleEntity
+end

app/serializers/board_simple_entity.rb

+# frozen_string_literal: true
+
+class BoardSimpleEntity < Grape::Entity
+  expose :id
+end

changelogs/unreleased/ce-3861-use-serializers-for-project-group-boards.yml

+---
+title: Refactor Board JSON serialization to use Grape::Entity instead of manual serialization
+  (to_json)
+merge_request:
+author:
+type: changed

spec/controllers/concerns/boards_responses_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe BoardsResponses do
+  let(:controller_class) do
+    Class.new do
+      include BoardsResponses
+    end
+  end
+
+  subject(:controller) { controller_class.new }
+
+  describe '#serialize_as_json' do
+    let!(:board) { create(:board) }
+
+    it 'serializes properly' do
+      expected = { id: board.id }
+
+      expect(subject.serialize_as_json(board).to_h).to include(expected)
+    end
+  end
+end

spec/serializers/board_serializer_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe BoardSerializer do
+  let(:resource) { create(:board) }
+  let(:json_entity) do
+    described_class.new
+        .represent(resource, serializer: serializer)
+        .with_indifferent_access
+  end
+
+  context 'serialization' do
+    let(:serializer) { 'board' }
+
+    it 'matches issue_sidebar json schema' do
+      expect(json_entity).to match_schema('board')
+    end
+  end
+end