Match against records rather than id, feedback:

https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/5142#note_13125605
https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/5142#note_13125611

spec/models/build_spec.rb

@@ -698,9 +698,9 @@ describe Ci::Build, models: true do
     end
     it 'returns builds from ref' do
-      build_ids = project.latest_success_builds_for('HEAD').map(&:id)
-      expect(build_ids).to eq([build.id])
+      builds = project.latest_success_builds_for('HEAD')
+      expect(builds).to contain_exactly(build)
     end
     it 'returns empty relation if the build cannot be found' do