1 files changed, 112 insertions, 0 deletions
diff --git a/spec/serializers/ci/dag_pipeline_entity_spec.rb b/spec/serializers/ci/dag_pipeline_entity_spec.rb
new file mode 100644
index 00000000000..4645451e146
--- /dev/null
+++ b/spec/serializers/ci/dag_pipeline_entity_spec.rb
@@ -0,0 +1,112 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Ci::DagPipelineEntity do
+  let_it_be(:request) { double(:request) }
+
+  let(:pipeline) { create(:ci_pipeline) }
+  let(:entity) { described_class.new(pipeline, request: request) }
+
+  describe '#as_json' do
+    subject { entity.as_json }
+
+    context 'when pipeline is empty' do
+      it 'contains stages' do
+        expect(subject).to include(:stages)
+
+        expect(subject[:stages]).to be_empty
+      end
+    end
+
+    context 'when pipeline has jobs' do
+      let!(:build_job)  { create(:ci_build, stage: 'build',  pipeline: pipeline) }
+      let!(:test_job)   { create(:ci_build, stage: 'test',   pipeline: pipeline) }
+      let!(:deploy_job) { create(:ci_build, stage: 'deploy', pipeline: pipeline) }
+
+      it 'contains 3 stages' do
+        stages = subject[:stages]
+
+        expect(stages.size).to eq 3
+        expect(stages.map { |s| s[:name] }).to contain_exactly('build', 'test', 'deploy')
+      end
+    end
+
+    context 'when pipeline has parallel jobs and DAG needs' do
+      let!(:stage_build)  { create(:ci_stage_entity, name: 'build',  position: 1, pipeline: pipeline) }
+      let!(:stage_test)   { create(:ci_stage_entity, name: 'test',   position: 2, pipeline: pipeline) }
+      let!(:stage_deploy) { create(:ci_stage_entity, name: 'deploy', position: 3, pipeline: pipeline) }
+
+      let!(:job_build_1) { create(:ci_build, name: 'build 1', stage: 'build', pipeline: pipeline) }
+      let!(:job_build_2) { create(:ci_build, name: 'build 2', stage: 'build', pipeline: pipeline) }
+
+      let!(:job_rspec_1) { create(:ci_build, name: 'rspec 1/2', stage: 'test', pipeline: pipeline) }
+      let!(:job_rspec_2) { create(:ci_build, name: 'rspec 2/2', stage: 'test', pipeline: pipeline) }
+
+      let!(:job_jest) do
+        create(:ci_build, name: 'jest', stage: 'test', scheduling_type: 'dag', pipeline: pipeline).tap do |job|
+          create(:ci_build_need, name: 'build 1', build: job)
+        end
+      end
+
+      let!(:job_deploy_ruby) do
+        create(:ci_build, name: 'deploy_ruby', stage: 'deploy', scheduling_type: 'dag', pipeline: pipeline).tap do |job|
+          create(:ci_build_need, name: 'rspec 1/2', build: job)
+          create(:ci_build_need, name: 'rspec 2/2', build: job)
+        end
+      end
+
+      let!(:job_deploy_js) do
+        create(:ci_build, name: 'deploy_js', stage: 'deploy', scheduling_type: 'dag', pipeline: pipeline).tap do |job|
+          create(:ci_build_need, name: 'jest', build: job)
+        end
+      end
+
+      it 'performs the smallest number of queries' do
+        log = ActiveRecord::QueryRecorder.new { subject }
+
+        # stages, project, builds, build_needs
+        expect(log.count).to eq 4
+      end
+
+      it 'contains all the data' do
+        expected_result = {
+          stages: [
+            {
+              name: 'build',
+              groups: [
+                { name: 'build 1', size: 1, jobs: [{ name: 'build 1' }] },
+                { name: 'build 2', size: 1, jobs: [{ name: 'build 2' }] }
+              ]
+            },
+            {
+              name: 'test',
+              groups: [
+                { name: 'jest', size: 1, jobs: [{ name: 'jest', needs: ['build 1'] }] },
+                { name: 'rspec', size: 2, jobs: [{ name: 'rspec 1/2' }, { name: 'rspec 2/2' }] }
+              ]
+            },
+            {
+              name: 'deploy',
+              groups: [
+                { name: 'deploy_js', size: 1, jobs: [{ name: 'deploy_js', needs: ['jest'] }] },
+                { name: 'deploy_ruby', size: 1, jobs: [{ name: 'deploy_ruby', needs: ['rspec 1/2', 'rspec 2/2'] }] }
+              ]
+            }
+          ]
+        }
+
+        expect(subject.fetch(:stages)).not_to be_empty
+
+        expect(subject.fetch(:stages)[0].fetch(:name)).to eq 'build'
+        expect(subject.fetch(:stages)[0]).to eq expected_result.fetch(:stages)[0]
+
+        expect(subject.fetch(:stages)[1].fetch(:name)).to eq 'test'
+        expect(subject.fetch(:stages)[1]).to eq expected_result.fetch(:stages)[1]
+
+        expect(subject.fetch(:stages)[2].fetch(:name)).to eq 'deploy'
+        expect(subject.fetch(:stages)[2]).to eq expected_result.fetch(:stages)[2]
+      end
+    end
+  end
+end