Render source job info in TriggeredPipelineEntity

Allow frontend to display which job triggered the downstream
pipeline.

app/models/ci/pipeline.rb

@@ -447,6 +447,10 @@ module Ci
       end
     end
 
+    def triggered_pipelines_with_preloads
+      triggered_pipelines.preload(:source_job)
+    end
+
     def legacy_stages
       if ::Gitlab::Ci::Features.composite_status?(project)
         legacy_stages_using_composite_status

app/serializers/pipeline_serializer.rb

@@ -60,8 +60,8 @@ class PipelineSerializer < BaseSerializer
         },
         pending_builds: :project,
         project: [:route, { namespace: :route }],
-        triggered_by_pipeline: [:project, :user],
-        triggered_pipelines: [:project, :user]
+        triggered_by_pipeline: [{ project: [:route, { namespace: :route }] }, :user],
+        triggered_pipelines: [{ project: [:route, { namespace: :route }] }, :user, :source_job]
       }
     ]
   end

app/serializers/triggered_pipeline_entity.rb

@@ -11,6 +11,12 @@ class TriggeredPipelineEntity < Grape::Entity
   expose :coverage
   expose :source
 
+  expose :source_job do
+    expose :name do |pipeline|
+      pipeline.source_job&.name
+    end
+  end
+
   expose :path do |pipeline|
     project_pipeline_path(pipeline.project, pipeline)
   end
@@ -27,7 +33,7 @@ class TriggeredPipelineEntity < Grape::Entity
     as: :triggered_by, with: TriggeredPipelineEntity,
     if: -> (_, opts) { can_read_details? && expand_for_path?(opts) }
 
-  expose :triggered_pipelines,
+  expose :triggered_pipelines_with_preloads,
     as: :triggered, using: TriggeredPipelineEntity,
     if: -> (_, opts) { can_read_details? && expand_for_path?(opts) }
 

changelogs/unreleased/render-job-details-on-downstream-pipelines.yml

+---
+title: Render source job info in TriggeredPipelineEntity
+merge_request: 35232
+author:
+type: added

spec/serializers/pipeline_details_entity_spec.rb

@@ -157,20 +157,30 @@ RSpec.describe PipelineDetailsEntity do
 
     context 'when pipeline triggered other pipeline' do
       let(:pipeline) { create(:ci_empty_pipeline) }
-      let(:build) { create(:ci_build, pipeline: pipeline) }
+      let(:build) { create(:ci_build, name: 'child', stage: 'test', pipeline: pipeline) }
+      let(:bridge) { create(:ci_bridge, name: 'cross-project', stage: 'build', pipeline: pipeline) }
+      let(:child_pipeline) { create(:ci_pipeline, project: pipeline.project) }
+      let(:cross_project_pipeline) { create(:ci_pipeline) }
 
       before do
-        create(:ci_sources_pipeline, source_job: build)
-        create(:ci_sources_pipeline, source_job: build)
+        create(:ci_sources_pipeline, source_job: build, pipeline: child_pipeline)
+        create(:ci_sources_pipeline, source_job: bridge, pipeline: cross_project_pipeline)
       end
 
-      it 'contains an information about depedent pipeline' do
+      it 'contains an information about dependent pipeline', :aggregate_failures do
         expect(subject[:triggered]).to be_a(Array)
         expect(subject[:triggered].length).to eq(2)
         expect(subject[:triggered].first[:path]).not_to be_nil
         expect(subject[:triggered].first[:details]).not_to be_nil
         expect(subject[:triggered].first[:details][:status]).not_to be_nil
         expect(subject[:triggered].first[:project]).not_to be_nil
+
+        source_jobs = subject[:triggered]
+          .index_by { |pipeline| pipeline[:id] }
+          .transform_values { |pipeline| pipeline.fetch(:source_job) }
+
+        expect(source_jobs[cross_project_pipeline.id][:name]).to eq('cross-project')
+        expect(source_jobs[child_pipeline.id][:name]).to eq('child')
       end
     end
   end

spec/serializers/pipeline_serializer_spec.rb

@@ -211,6 +211,33 @@ RSpec.describe PipelineSerializer do
         end
       end
 
+      context 'with triggered pipelines' do
+        let(:ref) { 'feature' }
+
+        before do
+          pipeline_1 = create(:ci_pipeline)
+          build_1 = create(:ci_build, pipeline: pipeline_1)
+          create(:ci_sources_pipeline, source_job: build_1)
+
+          pipeline_2 = create(:ci_pipeline)
+          build_2 = create(:ci_build, pipeline: pipeline_2)
+          create(:ci_sources_pipeline, source_job: build_2)
+        end
+
+        it 'verifies number of queries', :request_store do
+          recorded = ActiveRecord::QueryRecorder.new { subject }
+
+          # 99 queries by default + 2 related to preloading
+          # :source_pipeline and :source_job
+          # Existing numbers are high and require performance optimization
+          # https://gitlab.com/gitlab-org/gitlab/-/issues/225156
+          expected_queries = Gitlab.ee? ? 101 : 92
+
+          expect(recorded.count).to be_within(2).of(expected_queries)
+          expect(recorded.cached_count).to eq(0)
+        end
+      end
+
       def create_pipeline(status)
         create(:ci_empty_pipeline,
                project: project,