1 files changed, 138 insertions, 0 deletions
diff --git a/spec/workers/merge_requests/update_head_pipeline_worker_spec.rb b/spec/workers/merge_requests/update_head_pipeline_worker_spec.rb
new file mode 100644
index 00000000000..f3ea14ad539
--- /dev/null
+++ b/spec/workers/merge_requests/update_head_pipeline_worker_spec.rb
@@ -0,0 +1,138 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe MergeRequests::UpdateHeadPipelineWorker do
+  include ProjectForksHelper
+
+  let_it_be(:project) { create(:project, :repository) }
+
+  let(:ref) { 'master' }
+  let(:pipeline) { create(:ci_pipeline, project: project, ref: ref) }
+  let(:event) { Ci::PipelineCreatedEvent.new(data: { pipeline_id: pipeline.id }) }
+
+  subject { consume_event(event) }
+
+  def consume_event(event)
+    described_class.new.perform(event.class.name, event.data)
+  end
+
+  context 'when merge requests already exist for this source branch', :sidekiq_inline do
+    let(:merge_request_1) do
+      create(:merge_request, source_branch: 'feature', target_branch: "master", source_project: project)
+    end
+
+    let(:merge_request_2) do
+      create(:merge_request, source_branch: 'feature', target_branch: "v1.1.0", source_project: project)
+    end
+
+    context 'when related merge request is already merged' do
+      let!(:merged_merge_request) do
+        create(:merge_request, source_branch: 'master', target_branch: "branch_2", source_project: project, state: 'merged')
+      end
+
+      it 'does not schedule update head pipeline job' do
+        expect(UpdateHeadPipelineForMergeRequestWorker).not_to receive(:perform_async).with(merged_merge_request.id)
+
+        subject
+      end
+    end
+
+    context 'when the head pipeline sha equals merge request sha' do
+      let(:ref) { 'feature' }
+
+      before do
+        pipeline.update!(sha: project.repository.commit(ref).id)
+      end
+
+      it 'updates head pipeline of each merge request' do
+        merge_request_1
+        merge_request_2
+
+        subject
+
+        expect(merge_request_1.reload.head_pipeline).to eq(pipeline)
+        expect(merge_request_2.reload.head_pipeline).to eq(pipeline)
+      end
+    end
+
+    context 'when the head pipeline sha does not equal merge request sha' do
+      let(:ref) { 'feature' }
+
+      it 'does not update the head piepeline of MRs' do
+        merge_request_1
+        merge_request_2
+
+        subject
+
+        expect(merge_request_1.reload.head_pipeline).not_to eq(pipeline)
+        expect(merge_request_2.reload.head_pipeline).not_to eq(pipeline)
+      end
+    end
+
+    context 'when there is no pipeline for source branch' do
+      it "does not update merge request head pipeline" do
+        merge_request = create(:merge_request, source_branch: 'feature',
+                                               target_branch: "branch_1",
+                                               source_project: project)
+
+        subject
+
+        expect(merge_request.reload.head_pipeline).not_to eq(pipeline)
+      end
+    end
+
+    context 'when merge request target project is different from source project' do
+      let(:project) { fork_project(target_project, nil, repository: true) }
+      let(:target_project) { create(:project, :repository) }
+      let(:user) { create(:user) }
+      let(:ref) { 'feature' }
+
+      before do
+        project.add_developer(user)
+        pipeline.update!(sha: project.repository.commit(ref).id)
+      end
+
+      it 'updates head pipeline for merge request' do
+        merge_request = create(:merge_request, source_branch: 'feature',
+                                               target_branch: "master",
+                                               source_project: project,
+                                               target_project: target_project)
+
+        subject
+
+        expect(merge_request.reload.head_pipeline).to eq(pipeline)
+      end
+    end
+
+    context 'when the pipeline is not the latest for the branch' do
+      it 'does not update merge request head pipeline' do
+        merge_request = create(:merge_request, source_branch: 'master',
+                                               target_branch: "branch_1",
+                                               source_project: project)
+
+        create(:ci_pipeline, project: pipeline.project, ref: pipeline.ref)
+
+        subject
+
+        expect(merge_request.reload.head_pipeline).to be_nil
+      end
+    end
+
+    context 'when pipeline has errors' do
+      before do
+        pipeline.update!(yaml_errors: 'some errors', status: :failed)
+      end
+
+      it 'updates merge request head pipeline reference' do
+        merge_request = create(:merge_request, source_branch: 'master',
+                                               target_branch: 'feature',
+                                               source_project: project)
+
+        subject
+
+        expect(merge_request.reload.head_pipeline).to eq(pipeline)
+      end
+    end
+  end
+end