Adds some specs for stage optimistic locking

spec/lib/gitlab/import_export/safe_model_attributes.yml

@@ -220,6 +220,7 @@ Ci::Stage:
 - id
 - name
 - status
+- lock_version
 - project_id
 - pipeline_id
 - created_at

spec/models/ci/stage_spec.rb

@@ -54,7 +54,26 @@ describe Ci::Stage, :models do
       end
     end
 
+    context 'when stage is skipped' do
+      it 'updates status to skipped' do
+        expect { stage.update! }
+          .to change { stage.reload.status }
+          .to 'skipped'
+      end
+    end
+
     context 'when stage object is locked' do
+      before do
+        create(:ci_build, :failed, stage_id: stage.id)
+      end
+
+      it 'retries a lock to update a stage status' do
+        stage.lock_version = 100
+
+        stage.update!
+
+        expect(stage.reload).to be_failed
+      end
     end
   end
 end

spec/services/ci/retry_build_service_spec.rb

@@ -22,7 +22,7 @@ describe Ci::RetryBuildService, :services do
     %i[type lock_version target_url base_tags
        commit_id deployments erased_by_id last_deployment project_id
        runner_id tag_taggings taggings tags trigger_request_id
-       user_id auto_canceled_by_id retried].freeze
+       user_id auto_canceled_by_id retried stage_entity].freeze
 
   shared_examples 'build duplication' do
     let(:stage) do