List all available labels to the project on the labels API

lib/api/labels.rb

@@ -11,7 +11,7 @@ class Labels < Grape::API
       # Example Request:
       #   GET /projects/:id/labels
       get ':id/labels' do
-        present user_project.labels, with: Entities::Label, current_user: current_user
+        present available_labels, with: Entities::Label, current_user: current_user
       end
 
       # Creates a new label

spec/requests/api/labels_spec.rb

@@ -12,12 +12,18 @@
   end
 
   describe 'GET /projects/:id/labels' do
-    it 'returns project labels' do
+    it 'returns all available labels to the project' do
+      group = create(:group)
+      group_label = create(:group_label, group: group)
+      project.update(group: group)
+
       get api("/projects/#{project.id}/labels", user)
+
       expect(response).to have_http_status(200)
       expect(json_response).to be_an Array
-      expect(json_response.size).to eq(1)
-      expect(json_response.first['name']).to eq(label1.name)
+      expect(json_response.size).to eq(2)
+      expect(json_response.first['name']).to eq(group_label.name)
+      expect(json_response.second['name']).to eq(label1.name)
     end
   end