Expose degradation_threshold from CI config

This exposes the value from the CI YAML config variable
DEGRADATION_THRESHOLD.

https://gitlab.com/gitlab-org/gitlab/-/merge_requests/21824

app/models/ci/build.rb

@@ -32,6 +32,9 @@ module Ci
       scheduler_failure: 2
     }.freeze
 
+    CODE_NAVIGATION_JOB_NAME = 'code_navigation'
+    DEGRADATION_THRESHOLD_VARIABLE_NAME = 'DEGRADATION_THRESHOLD'
+
     has_one :deployment, as: :deployable, class_name: 'Deployment'
     has_one :resource, class_name: 'Ci::Resource', inverse_of: :build
     has_many :trace_sections, class_name: 'Ci::BuildTraceSection'
@@ -917,6 +920,11 @@ module Ci
         failure_reason: :data_integrity_failure)
     end
 
+    def degradation_threshold
+      var = yaml_variables.find { |v| v[:key] == DEGRADATION_THRESHOLD_VARIABLE_NAME }
+      var[:value]&.to_i if var
+    end
+
     private
 
     def dependencies

doc/user/project/merge_requests/browser_performance_testing.md

@@ -123,6 +123,26 @@ documentation.
 TIP: **Tip:**
 Key metrics are automatically extracted and shown in the merge request widget.
 
+### Configuring degradation threshold
+
+> [Introduced](https://gitlab.com/gitlab-org/gitlab/issues/27599) in GitLab 13.0.
+
+You can configure the sensitivity of degradation alerts to avoid getting alerts for minor drops in metrics.
+This is done by setting the `DEGRADATION_THRESHOLD` variable. In the example below, the alert will only show up
+if the `Total Score` metric degrades by 5 points or more:
+
+```yaml
+include:
+  template: Verify/Browser-Performance.gitlab-ci.yml
+
+performance:
+  variables:
+    URL: https://example.com
+    DEGRADATION_THRESHOLD: 5
+```
+
+The `Total Score` metric is based on sitespeed.io's [coach performance score](https://www.sitespeed.io/documentation/sitespeed.io/metrics/#performance-score). There is more information in [the coach documentation](https://www.sitespeed.io/documentation/coach/how-to/#what-do-the-coach-do).
+
 ### Performance testing on Review Apps
 
 The above CI YAML configuration is great for testing against static environments, and it can

ee/app/assets/javascripts/vue_merge_request_widget/mr_widget_options.vue

@@ -14,6 +14,7 @@ import MrWidgetApprovals from './components/approvals/approvals.vue';
 import MrWidgetGeoSecondaryNode from './components/states/mr_widget_secondary_geo_node.vue';
 import MergeTrainHelperText from './components/merge_train_helper_text.vue';
 import { MTWPS_MERGE_STRATEGY } from '~/vue_merge_request_widget/constants';
+import { TOTAL_SCORE_METRIC_NAME } from 'ee/vue_merge_request_widget/stores/constants';
 
 export default {
   components: {
@@ -65,9 +66,29 @@ export default {
           (this.mr.performanceMetrics.improved && this.mr.performanceMetrics.improved.length > 0))
       );
     },
-    shouldRenderPerformance() {
+    hasPerformancePaths() {
       const { performance } = this.mr || {};
-      return performance && performance.head_path && performance.base_path;
+
+      return Boolean(performance?.head_path && performance?.base_path);
+    },
+    degradedTotalScore() {
+      return this.mr?.performanceMetrics?.degraded.find(
+        metric => metric.name === TOTAL_SCORE_METRIC_NAME,
+      );
+    },
+    hasPerformanceDegradation() {
+      const threshold = this.mr?.performance?.degradation_threshold || 0;
+
+      if (!threshold) {
+        return true;
+      }
+
+      const totalScoreDelta = this.degradedTotalScore?.delta || 0;
+
+      return threshold + totalScoreDelta <= 0;
+    },
+    shouldRenderPerformance() {
+      return this.hasPerformancePaths && this.hasPerformanceDegradation;
     },
     shouldRenderSecurityReport() {
       const { enabledReports } = this.mr;
@@ -170,7 +191,7 @@ export default {
         this.fetchCodeQuality();
       }
     },
-    shouldRenderPerformance(newVal) {
+    hasPerformancePaths(newVal) {
       if (newVal) {
         this.fetchPerformance();
       }

ee/app/assets/javascripts/vue_merge_request_widget/stores/constants.js

+/* eslint-disable import/prefer-default-export */
+
+// This is the name of Sitespeed's Overall Score metric in the performance report
+export const TOTAL_SCORE_METRIC_NAME = 'Total Score';

ee/app/assets/javascripts/vue_merge_request_widget/stores/mr_widget_store.js

@@ -122,7 +122,6 @@ export default class MergeRequestStore extends CEMergeRequestStore {
   comparePerformanceMetrics(headMetrics, baseMetrics) {
     const headMetricsIndexed = MergeRequestStore.normalizePerformanceMetrics(headMetrics);
     const baseMetricsIndexed = MergeRequestStore.normalizePerformanceMetrics(baseMetrics);
-
     const improved = [];
     const degraded = [];
 

ee/app/presenters/ee/ci/pipeline_presenter.rb

@@ -37,6 +37,13 @@ module EE
             proxy: true)
         end
       end
+
+      def degradation_threshold
+        if (job_artifact = batch_lookup_report_artifact_for_file_type(:performance)) &&
+            can?(current_user, :read_build, job_artifact.job)
+          job_artifact.job.degradation_threshold
+        end
+      end
     end
   end
 end

ee/app/serializers/ee/merge_request_widget_entity.rb

@@ -27,6 +27,11 @@ module EE
       end
 
       expose :performance, if: -> (mr, _) { head_pipeline_downloadable_path_for_report_type(:performance) } do
+        expose :degradation_threshold do |merge_request|
+          merge_request.head_pipeline&.present(current_user: current_user)
+            &.degradation_threshold
+        end
+
         expose :head_path do |merge_request|
           head_pipeline_downloadable_path_for_report_type(:performance)
         end

ee/changelogs/unreleased/eb-sitespeed-degradation-threshold.yml

+---
+title: Support setting threshold for browser performance degradation through CI config
+merge_request: 21824
+author:
+type: added

ee/spec/frontend/vue_mr_widget/ee_mr_widget_options_spec.js

@@ -40,6 +40,11 @@ describe('ee merge request widget options', () => {
   let mock;
   let Component;
 
+  const DEFAULT_PERFORMANCE = {
+    head_path: 'head.json',
+    base_path: 'base.json',
+  };
+
   beforeEach(() => {
     delete mrWidgetOptions.extends.el; // Prevent component mounting
 
@@ -65,8 +70,15 @@ describe('ee merge request widget options', () => {
     });
   });
 
+  const findPerformanceWidget = () => vm.$el.querySelector('.js-performance-widget');
   const findSecurityWidget = () => vm.$el.querySelector('.js-security-widget');
 
+  const setPerformance = (data = {}) => {
+    const performance = { ...DEFAULT_PERFORMANCE, ...data };
+    gl.mrWidgetData.performance = performance;
+    vm.mr.performance = performance;
+  };
+
   const VULNERABILITY_FEEDBACK_ENDPOINT = 'vulnerability_feedback_path';
 
   describe('SAST', () => {
@@ -487,13 +499,10 @@ describe('ee merge request widget options', () => {
         mock.onGet('base.json').reply(200, basePerformance);
         vm = mountComponent(Component, { mrData: gl.mrWidgetData });
 
-        vm.mr.performance = {
-          head_path: 'head.json',
-          base_path: 'base.json',
-        };
+        vm.mr.performance = { ...DEFAULT_PERFORMANCE };
 
         vm.$nextTick(() => {
-          expect(trimText(vm.$el.querySelector('.js-performance-widget').textContent)).toContain(
+          expect(trimText(findPerformanceWidget().textContent)).toContain(
             'Loading performance report',
           );
 
@@ -504,15 +513,14 @@ describe('ee merge request widget options', () => {
 
     describe('with successful request', () => {
       beforeEach(() => {
-        mock.onGet('head.json').reply(200, headPerformance);
-        mock.onGet('base.json').reply(200, basePerformance);
+        mock.onGet(DEFAULT_PERFORMANCE.head_path).reply(200, headPerformance);
+        mock.onGet(DEFAULT_PERFORMANCE.base_path).reply(200, basePerformance);
         vm = mountComponent(Component, { mrData: gl.mrWidgetData });
+      });
 
-        gl.mrWidgetData.performance = {
-          head_path: 'head.json',
-          base_path: 'base.json',
-        };
-        vm.mr.performance = gl.mrWidgetData.performance;
+      describe('default', () => {
+        beforeEach(() => {
+          setPerformance();
         });
 
         it('should render provided data', done => {
@@ -531,7 +539,9 @@ describe('ee merge request widget options', () => {
 
               Vue.nextTick(() => {
                 expect(
-                trimText(vm.$el.querySelector('.js-performance-widget .js-code-text').textContent),
+                  trimText(
+                    vm.$el.querySelector('.js-performance-widget .js-code-text').textContent,
+                  ),
                 ).toEqual('Performance metrics improved on 2 points');
                 done();
               });
@@ -544,7 +554,9 @@ describe('ee merge request widget options', () => {
 
               Vue.nextTick(() => {
                 expect(
-                trimText(vm.$el.querySelector('.js-performance-widget .js-code-text').textContent),
+                  trimText(
+                    vm.$el.querySelector('.js-performance-widget .js-code-text').textContent,
+                  ),
                 ).toEqual('Performance metrics degraded on 1 point');
                 done();
               });
@@ -553,16 +565,39 @@ describe('ee merge request widget options', () => {
         });
       });
 
+      describe.each`
+        degradation_threshold | shouldExist
+        ${1}                  | ${true}
+        ${3}                  | ${false}
+      `(
+        'with degradation_threshold = $degradation_threshold',
+        ({ degradation_threshold, shouldExist }) => {
+          beforeEach(() => {
+            setPerformance({ degradation_threshold });
+
+            return waitForPromises();
+          });
+
+          if (shouldExist) {
+            it('should render widget when total score degradation is above threshold', () => {
+              expect(findPerformanceWidget()).toExist();
+            });
+          } else {
+            it('should not render widget when total score degradation is below threshold', () => {
+              expect(findPerformanceWidget()).not.toExist();
+            });
+          }
+        },
+      );
+    });
+
     describe('with empty successful request', () => {
       beforeEach(done => {
-        mock.onGet('head.json').reply(200, []);
-        mock.onGet('base.json').reply(200, []);
+        mock.onGet(DEFAULT_PERFORMANCE.head_path).reply(200, []);
+        mock.onGet(DEFAULT_PERFORMANCE.base_path).reply(200, []);
         vm = mountComponent(Component, { mrData: gl.mrWidgetData });
 
-        gl.mrWidgetData.performance = {
-          head_path: 'head.json',
-          base_path: 'base.json',
-        };
+        gl.mrWidgetData.performance = { ...DEFAULT_PERFORMANCE };
         vm.mr.performance = gl.mrWidgetData.performance;
 
         // wait for network request from component watch update method
@@ -590,14 +625,11 @@ describe('ee merge request widget options', () => {
 
     describe('with failed request', () => {
       beforeEach(() => {
-        mock.onGet('head.json').reply(500, []);
-        mock.onGet('base.json').reply(500, []);
+        mock.onGet(DEFAULT_PERFORMANCE.head_path).reply(500, []);
+        mock.onGet(DEFAULT_PERFORMANCE.base_path).reply(500, []);
         vm = mountComponent(Component, { mrData: gl.mrWidgetData });
 
-        gl.mrWidgetData.performance = {
-          head_path: 'head.json',
-          base_path: 'base.json',
-        };
+        gl.mrWidgetData.performance = { ...DEFAULT_PERFORMANCE };
         vm.mr.performance = gl.mrWidgetData.performance;
       });
 

ee/spec/frontend/vue_mr_widget/mock_data.js

@@ -113,7 +113,7 @@ export const headPerformance = [
     subject: '/some/other/path',
     metrics: [
       {
-        name: 'Sitespeed Score',
+        name: 'Total Score',
         value: 79,
         desiredSize: 'larger',
       },
@@ -149,7 +149,7 @@ export const basePerformance = [
     subject: '/some/other/path',
     metrics: [
       {
-        name: 'Sitespeed Score',
+        name: 'Total Score',
         value: 80,
         desiredSize: 'larger',
       },

ee/spec/serializers/merge_request_widget_entity_spec.rb

@@ -99,6 +99,51 @@ describe MergeRequestWidgetEntity do
     end
   end
 
+  describe 'degradation_threshold' do
+    let!(:head_pipeline) { create(:ci_empty_pipeline, project: project) }
+
+    before do
+      allow(merge_request).to receive_messages(
+        base_pipeline: pipeline,
+        head_pipeline: head_pipeline
+      )
+
+      allow(head_pipeline).to receive(:available_licensed_report_type?).and_return(true)
+
+      create(
+        :ee_ci_build,
+        :performance,
+        pipeline: head_pipeline,
+        yaml_variables: yaml_variables
+      )
+    end
+
+    context "when head pipeline's performance build has the threshold variable defined" do
+      let(:yaml_variables) do
+        [
+          { key: 'FOO', value: 'BAR' },
+          { key: 'DEGRADATION_THRESHOLD', value: '5' }
+        ]
+      end
+
+      it "returns the value of the variable" do
+        expect(subject.as_json[:performance][:degradation_threshold]).to eq(5)
+      end
+    end
+
+    context "when head pipeline's performance build has no threshold variable defined" do
+      let(:yaml_variables) do
+        [
+          { key: 'FOO', value: 'BAR' }
+        ]
+      end
+
+      it "returns nil" do
+        expect(subject.as_json[:performance][:degradation_threshold]).to be_nil
+      end
+    end
+  end
+
   describe '#license_scanning', :request_store do
     before do
       allow(merge_request).to receive_messages(head_pipeline: pipeline, target_project: project)

spec/models/ci/build_spec.rb

@@ -4414,4 +4414,31 @@ describe Ci::Build do
       it { is_expected.to be_nil }
     end
   end
+
+  describe '#degradation_threshold' do
+    subject { build.degradation_threshold }
+
+    context 'when threshold variable is defined' do
+      before do
+        build.yaml_variables = [
+          { key: 'SOME_VAR_1', value: 'SOME_VAL_1' },
+          { key: 'DEGRADATION_THRESHOLD', value: '5' },
+          { key: 'SOME_VAR_2', value: 'SOME_VAL_2' }
+        ]
+      end
+
+      it { is_expected.to eq(5) }
+    end
+
+    context 'when threshold variable is not defined' do
+      before do
+        build.yaml_variables = [
+          { key: 'SOME_VAR_1', value: 'SOME_VAL_1' },
+          { key: 'SOME_VAR_2', value: 'SOME_VAL_2' }
+        ]
+      end
+
+      it { is_expected.to be_nil }
+    end
+  end
 end