Add missing specs for CI pipeline stage entity

[ci skip]

app/serializers/stage_entity.rb

@@ -2,6 +2,7 @@ class StageEntity < Grape::Entity
   include RequestAwareEntity
 
   expose :name
+
   expose :status do |stage, options|
     StatusEntity.represent(
       stage.detailed_status(request.user),

spec/serializers/stage_entity_spec.rb

+require 'spec_helper'
+
+describe StageEntity do
+  let(:pipeline) { create(:ci_pipeline) }
+  let(:request) { double('request') }
+  let(:user) { create(:user) }
+
+  let(:entity) do
+    described_class.new(stage, request: request)
+  end
+
+  let(:stage) do
+    build(:ci_stage, pipeline: pipeline, name: 'test')
+  end
+
+  before do
+    allow(request).to receive(:user).and_return(user)
+  end
+
+  describe '#as_json' do
+    subject { entity.as_json }
+
+    it 'contains relevant fields' do
+      expect(subject).to include :name, :status, :path
+    end
+
+    it 'contains detailed status' do
+      expect(subject[:status]).to include :text, :label, :group, :icon
+    end
+
+    it 'contains valid name' do
+      expect(subject[:name]).to eq 'test'
+    end
+
+    it 'contains path to the stage' do
+      expect(subject[:path])
+        .to include "pipelines/#{pipeline.id}##{stage.name}"
+    end
+  end
+end