Fix environments are stopped incorrectly in merge requests

This commit fixes the regression that the environments
are stopped incorrectly in merge requests.

This fix is still behind the feature flag.

app/models/merge_request.rb

@@ -1444,7 +1444,7 @@ def mergeable_ci_state?
   # This method is for looking for active environments which created via pipelines for merge requests.
   # Since deployments run on a merge request ref (e.g. `refs/merge-requests/:iid/head`),
   # we cannot look up environments with source branch name.
-  def environments
+  def legacy_environments
     return Environment.none unless actual_head_pipeline&.merge_request?
     build_for_actual_head_pipeline = Ci::Build.latest.where(pipeline: actual_head_pipeline)
@@ -1458,6 +1458,14 @@ def environments
     Environment.where(project: project, name: environments)
   end
+  def environments_in_head_pipeline
+    if ::Feature.enabled?(:fix_related_environments_for_merge_requests, target_project, default_enabled: :yaml)
+      actual_head_pipeline&.environments_in_self_and_descendants || Environment.none
+    else
+      legacy_environments
+    end
+  end
+
   def fetch_ref!
     target_project.repository.fetch_source_branch!(source_project.repository, source_branch, ref_path)
   end

app/services/environments/stop_service.rb

@@ -19,7 +19,7 @@ def execute_for_branch(branch_name)
     end
     def execute_for_merge_request(merge_request)
-      merge_request.environments.each { |environment| execute(environment) }
+      merge_request.environments_in_head_pipeline.each { |environment| execute(environment) }
     end
     private

app/services/merge_requests/base_service.rb

@@ -72,7 +72,7 @@ def cleanup_environments(merge_request)
     end
     def cancel_review_app_jobs!(merge_request)
-      environments = merge_request.environments.in_review_folder.available
+      environments = merge_request.environments_in_head_pipeline.in_review_folder.available
       environments.each { |environment| environment.cancel_deployment_jobs! }
     end

config/feature_flags/development/fix_related_environments_for_merge_requests.yml

+---
+name: fix_related_environments_for_merge_requests
+introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/83382
+rollout_issue_url: https://gitlab.com/gitlab-org/gitlab/-/issues/356642
+milestone: '14.10'
+type: development
+group: group::release
+default_enabled: false

spec/factories/ci/builds.rb

@@ -175,6 +175,44 @@
       end
     end
+    trait :prepare_staging do
+      name { 'prepare staging' }
+      environment { 'staging' }
+
+      options do
+        {
+          script: %w(ls),
+          environment: { name: 'staging', action: 'prepare' }
+        }
+      end
+
+      set_expanded_environment_name
+    end
+
+    trait :stop_staging do
+      name { 'stop staging' }
+      environment { 'staging' }
+
+      options do
+        {
+          script: %w(ls),
+          environment: { name: 'staging', action: 'stop' }
+        }
+      end
+
+      set_expanded_environment_name
+    end
+
+    trait :set_expanded_environment_name do
+      after(:build) do |build, evaluator|
+        build.assign_attributes(
+          metadata_attributes: {
+            expanded_environment_name: build.expanded_environment_name
+          }
+        )
+      end
+    end
+
     trait :allowed_to_fail do
       allow_failure { true }
     end

spec/models/merge_request_spec.rb

@@ -3550,8 +3550,8 @@ def set_compare(merge_request)
     end
   end
-  describe "#environments" do
-    subject { merge_request.environments }
+  describe "#legacy_environments" do
+    subject { merge_request.legacy_environments }
     let(:merge_request) { create(:merge_request, source_branch: 'feature', target_branch: 'master') }
     let(:project) { merge_request.project }

spec/services/environments/stop_service_spec.rb

@@ -198,6 +198,30 @@
         expect(pipeline.environments_in_self_and_descendants.first).to be_stopped
       end
+
+      context 'with environment related jobs ' do
+        let!(:environment) { create(:environment, :available, name: 'staging', project: project) }
+        let!(:prepare_staging_job) { create(:ci_build, :prepare_staging, pipeline: pipeline, project: project) }
+        let!(:stop_staging_job) { create(:ci_build, :stop_staging, :manual, pipeline: pipeline, project: project) }
+
+        it 'does not stop environments that was not started by the merge request' do
+          subject
+
+          expect(prepare_staging_job.persisted_environment.state).to eq('available')
+        end
+
+        context 'when fix_related_environments_for_merge_requests feature flag is disabled' do
+          before do
+            stub_feature_flags(fix_related_environments_for_merge_requests: false)
+          end
+
+          it 'stops unrelated environments too' do
+            subject
+
+            expect(prepare_staging_job.persisted_environment.state).to eq('stopped')
+          end
+        end
+      end
     end
     context 'when user is a reporter' do