Move Auto DevOps Test.gitlab-ci.yml to rules

Part of https://gitlab.com/gitlab-org/gitlab/-/issues/213336

Started out as a revert of merge request
https://gitlab.com/gitlab-org/gitlab/-/merge_requests/25492

changelogs/unreleased/revert-0ddee28a.yml

+---
+title: Move Auto DevOps Test.gitlab-ci.yml template to rules syntax instead of only/except
+merge_request: 30876
+author:
+type: changed

lib/gitlab/ci/templates/Jobs/Test.gitlab-ci.yml

@@ -15,9 +15,7 @@ test:
     - export DATABASE_URL="postgres://${POSTGRES_USER}:${POSTGRES_PASSWORD}@${DB_HOST}:5432/${POSTGRES_DB}"
     - cp -R . /tmp/app
     - /bin/herokuish buildpack test
-  only:
-    - branches
-    - tags
-  except:
-    variables:
-      - $TEST_DISABLED
+  rules:
+    - if: '$TEST_DISABLED'
+      when: never
+    - if: '$CI_COMMIT_TAG || $CI_COMMIT_BRANCH'

spec/lib/gitlab/ci/templates/Jobs/test_gitlab_ci_yaml_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe 'Jobs/Test.gitlab-ci.yml' do
+  subject(:template) { Gitlab::Template::GitlabCiYmlTemplate.find('Jobs/Test') }
+
+  describe 'the created pipeline' do
+    let_it_be(:user) { create(:admin) }
+    let_it_be(:project) { create(:project, :repository) }
+
+    let(:default_branch) { 'master' }
+    let(:pipeline_ref) { default_branch }
+    let(:service) { Ci::CreatePipelineService.new(project, user, ref: pipeline_ref) }
+    let(:pipeline) { service.execute!(:push) }
+    let(:build_names) { pipeline.builds.pluck(:name) }
+
+    before do
+      stub_ci_pipeline_yaml_file(template.content)
+      allow_any_instance_of(Ci::BuildScheduleWorker).to receive(:perform).and_return(true)
+      allow(project).to receive(:default_branch).and_return(default_branch)
+    end
+
+    context 'on master' do
+      it 'creates the test job' do
+        expect(build_names).to contain_exactly('test')
+      end
+    end
+
+    context 'on another branch' do
+      let(:pipeline_ref) { 'feature' }
+
+      it 'creates the test job' do
+        expect(build_names).to contain_exactly('test')
+      end
+    end
+
+    context 'on tag' do
+      let(:pipeline_ref) { 'v1.0.0' }
+
+      it 'creates the test job' do
+        expect(pipeline).to be_tag
+        expect(build_names).to contain_exactly('test')
+      end
+    end
+
+    context 'on merge request' do
+      let(:service) { MergeRequests::CreatePipelineService.new(project, user) }
+      let(:merge_request) { create(:merge_request, :simple, source_project: project) }
+      let(:pipeline) { service.execute(merge_request) }
+
+      it 'has no jobs' do
+        expect(pipeline).to be_merge_request_event
+        expect(build_names).to be_empty
+      end
+    end
+
+    context 'TEST_DISABLED is set' do
+      before do
+        create(:ci_variable, key: 'TEST_DISABLED', value: 'true', project: project)
+      end
+
+      context 'on master' do
+        it 'has no jobs' do
+          expect { pipeline }.to raise_error(Ci::CreatePipelineService::CreateError)
+        end
+      end
+
+      context 'on another branch' do
+        let(:pipeline_ref) { 'feature' }
+
+        it 'has no jobs' do
+          expect { pipeline }.to raise_error(Ci::CreatePipelineService::CreateError)
+        end
+      end
+
+      context 'on tag' do
+        let(:pipeline_ref) { 'v1.0.0' }
+
+        it 'has no jobs' do
+          expect { pipeline }.to raise_error(Ci::CreatePipelineService::CreateError)
+        end
+      end
+    end
+  end
+end