Ensure trial status popover events include gitlab_experiment context

app/assets/javascripts/experimentation/utils.js

@@ -3,7 +3,12 @@ import { get } from 'lodash';
 import { DEFAULT_VARIANT, CANDIDATE_VARIANT, TRACKING_CONTEXT_SCHEMA } from './constants';
 
 function getExperimentsData() {
-  return get(window, ['gon', 'experiment'], {});
+  // Pull from deprecated window.gon.experiment
+  const experimentsFromGon = get(window, ['gon', 'experiment'], {});
+  // Pull from preferred window.gl.experiments
+  const experimentsFromGl = get(window, ['gl', 'experiments'], {});
+
+  return { ...experimentsFromGon, ...experimentsFromGl };
 }
 
 function convertExperimentDataToExperimentContext(experimentData) {

app/views/layouts/_published_experiments.html.haml

+= javascript_tag(nonce: content_security_policy_nonce) do
+  :plain
+    gl = window.gl || {};
+    gl.experiments = #{raw ApplicationExperiment.published_experiments.reject { |name, data| data[:excluded] }.to_json};

app/views/layouts/application.html.haml

@@ -16,4 +16,5 @@
 
     = render 'layouts/img_loader'
 
+    = render 'layouts/published_experiments'
     = yield :scripts_body

doc/development/experiment_guide/gitlab_experiment.md

@@ -92,7 +92,7 @@ end
 ```
 
 When this code executes, the experiment is run, a variant is assigned, and (if within a
-controller or view) a `window.gon.experiment.pill_color` object will be available in the
+controller or view) a `window.gl.experiments.pill_color` object will be available in the
 client layer, with details like:
 
 - The assigned variant.
@@ -522,14 +522,14 @@ shared example: [tracks assignment and records the subject](https://gitlab.com/g
 
 This is in flux as of GitLab 13.10, and can't be documented just yet.
 
-Any experiment that's been run in the request lifecycle surfaces in `window.gon.experiment`,
+Any experiment that's been run in the request lifecycle surfaces in and `window.gl.experiments`,
 and matches [this schema](https://gitlab.com/gitlab-org/iglu/-/blob/master/public/schemas/com.gitlab/gitlab_experiment/jsonschema/1-0-0)
 so you can use it when resolving some concepts around experimentation in the client layer.
 
 ### Use experiments in Vue
 
 With the `gitlab-experiment` component, you can define slots that match the name of the
-variants pushed to `window.gon.experiment`. For example, if we alter the `pill_color`
+variants pushed to `window.gl.experiments`. For example, if we alter the `pill_color`
 experiment to just use the default variants of `control` and `candidate` like so:
 
 ```ruby
@@ -587,7 +587,51 @@ For example, the Vue component for the previously-defined `pill_color` experimen
 ```
 
 NOTE:
-When there is no experiment data in the `window.gon.experiment` object for the given experiment name, the `control` slot will be used, if it exists.
+When there is no experiment data in the `window.gl.experiments` object for the given experiment name, the `control` slot will be used, if it exists.
+
+## Test with Jest
+
+### Stub Helpers
+
+You can stub experiments using the `stubExperiments` helper defined in `spec/frontend/__helpers__/experimentation_helper.js`.
+
+```javascript
+import { stubExperiments } from 'helpers/experimentation_helper';
+import { getExperimentData } from '~/experimentation/utils';
+
+describe('when my_experiment is enabled', () => {
+  beforeEach(() => {
+    stubExperiments({ my_experiment: 'candidate' });
+  });
+
+  it('sets the correct data', () => {
+    expect(getExperimentData('my_experiment')).toEqual({ experiment: 'my_experiment', variant: 'candidate' });
+  });
+});
+```
+
+NOTE:
+This method of stubbing in Jest specs will not automatically un-stub itself at the end of the test. We merge our stubbed experiment in with all the other global data in `window.gl`. If you need to remove the stubbed experiment(s) after your test or ensure a clean global object before your test, you'll need to manage the global object directly yourself:
+
+```javascript
+desribe('tests that care about global state', () => {
+  const originalObjects = [];
+
+  beforeEach(() => {
+    // For backwards compatibility for now, we're using both window.gon & window.gl
+    originalObjects.push(window.gon, window.gl);
+  });
+
+  afterEach(() => {
+    [window.gon, window.gl] = originalObjects;
+  });
+
+  it('stubs experiment in fresh global state', () => {
+    stubExperiment({ my_experiment: 'candidate' });
+    // ...
+  });
+})
+```
 
 ## Notes on feature flags
 

ee/spec/frontend/vue_mr_widget/components/states/mr_widget_enable_feature_prompt_spec.js

 import { mount } from '@vue/test-utils';
 import MrWidgetEnableFeaturePrompt from 'ee/vue_merge_request_widget/components/states/mr_widget_enable_feature_prompt.vue';
-import { assignGitlabExperiment } from 'helpers/experimentation_helper';
+import { stubExperiments } from 'helpers/experimentation_helper';
 import CiIcon from '~/vue_shared/components/ci_icon.vue';
 
 const FEATURE = 'my_feature_name';
@@ -30,19 +30,16 @@ describe('MrWidgetEnableFeaturePrompt', () => {
   });
 
   describe('when the experiment is not enabled', () => {
-    beforeAll(() => {
-      assignGitlabExperiment(FEATURE, 'control');
-    });
-
     it('renders nothing', () => {
+      stubExperiments({ [FEATURE]: 'control' });
       expect(wrapper.text()).toBe('');
     });
   });
 
   describe('when the experiment is enabled', () => {
     beforeAll(() => {
+      stubExperiments({ [FEATURE]: 'candidate' });
       localStorage.removeItem(LOCAL_STORAGE_KEY);
-      assignGitlabExperiment(FEATURE, 'candidate');
     });
 
     it('shows a neutral icon', () => {

ee/spec/frontend/vue_mr_widget/ee_mr_widget_options_spec.js

@@ -24,7 +24,7 @@ import {
   coverageFuzzingDiffSuccessMock,
   apiFuzzingDiffSuccessMock,
 } from 'ee_jest/vue_shared/security_reports/mock_data';
-import { assignGitlabExperiment } from 'helpers/experimentation_helper';
+import { stubExperiments } from 'helpers/experimentation_helper';
 import createMockApollo from 'helpers/mock_apollo_helper';
 import { TEST_HOST } from 'helpers/test_constants';
 import { trimText } from 'helpers/text_helper';
@@ -221,7 +221,9 @@ describe('ee merge request widget options', () => {
       });
 
       describe('security_reports_mr_widget_prompt experiment', () => {
-        assignGitlabExperiment('security_reports_mr_widget_prompt', 'candidate');
+        beforeEach(() => {
+          stubExperiments({ security_reports_mr_widget_prompt: 'candidate' });
+        });
 
         it('prompts to enable the feature', () => {
           createComponent({ propsData: { mrData: mockData } });

spec/frontend/__helpers__/experimentation_helper.js

 import { merge } from 'lodash';
 
+// This helper is for specs that use `gitlab/experimentation` module
 export function withGonExperiment(experimentKey, value = true) {
   let origGon;
 
@@ -12,16 +13,26 @@ export function withGonExperiment(experimentKey, value = true) {
     window.gon = origGon;
   });
 }
-// This helper is for specs that use `gitlab-experiment` utilities, which have a different schema that gets pushed via Gon compared to `Experimentation Module`
-export function assignGitlabExperiment(experimentKey, variant) {
-  let origGon;
 
-  beforeEach(() => {
-    origGon = window.gon;
-    window.gon = { experiment: { [experimentKey]: { variant } } };
-  });
+// The following helper is for specs that use `gitlab-experiment` utilities,
+// which have a different schema that gets pushed to the frontend compared to
+// the `Experimentation` Module.
+//
+// Usage: stubExperiments({ experiment_feature_flag_name: 'variant_name', ... })
+export function stubExperiments(experiments = {}) {
+  // Deprecated
+  window.gon = window.gon || {};
+  window.gon.experiment = window.gon.experiment || {};
+  // Preferred
+  window.gl = window.gl || {};
+  window.gl.experiments = window.gl.experiemnts || {};
 
-  afterEach(() => {
-    window.gon = origGon;
+  Object.entries(experiments).forEach(([name, variant]) => {
+    const experimentData = { experiment: name, variant };
+
+    // Deprecated
+    window.gon.experiment[name] = experimentData;
+    // Preferred
+    window.gl.experiments[name] = experimentData;
   });
 }

spec/frontend/boards/components/new_board_button_spec.js

@@ -2,7 +2,7 @@ import { mount } from '@vue/test-utils';
 import { GlButton } from '@gitlab/ui';
 import NewBoardButton from '~/boards/components/new_board_button.vue';
 import { extendedWrapper } from 'helpers/vue_test_utils_helper';
-import { assignGitlabExperiment } from 'helpers/experimentation_helper';
+import { stubExperiments } from 'helpers/experimentation_helper';
 import eventHub from '~/boards/eventhub';
 
 const FEATURE = 'prominent_create_board_btn';
@@ -28,7 +28,9 @@ describe('NewBoardButton', () => {
   });
 
   describe('control variant', () => {
-    assignGitlabExperiment(FEATURE, 'control');
+    beforeAll(() => {
+      stubExperiments({ [FEATURE]: 'control' });
+    });
 
     it('renders nothing', () => {
       wrapper = createComponent();
@@ -38,7 +40,9 @@ describe('NewBoardButton', () => {
   });
 
   describe('candidate variant', () => {
-    assignGitlabExperiment(FEATURE, 'candidate');
+    beforeAll(() => {
+      stubExperiments({ [FEATURE]: 'candidate' });
+    });
 
     it('renders New board button when `candidate` variant', () => {
       wrapper = createComponent();

spec/views/layouts/_published_experiments.html.haml_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe 'layouts/_published_experiments', :experiment do
+  before do
+    stub_const('TestControlExperiment', ApplicationExperiment)
+    stub_const('TestCandidateExperiment', ApplicationExperiment)
+    stub_const('TestExcludedExperiment', ApplicationExperiment)
+
+    TestControlExperiment.new('test_control').tap do |e|
+      e.variant(:control)
+      e.publish
+    end
+    TestCandidateExperiment.new('test_candidate').tap do |e|
+      e.variant(:candidate)
+      e.publish
+    end
+    TestExcludedExperiment.new('test_excluded').tap do |e|
+      e.exclude!
+      e.publish
+    end
+
+    render
+  end
+
+  it 'renders out data for all non-excluded, published experiments' do
+    output = rendered
+
+    expect(output).to include('gl.experiments = {')
+    expect(output).to match(/"test_control":\{[^}]*"variant":"control"/)
+    expect(output).to match(/"test_candidate":\{[^}]*"variant":"candidate"/)
+    expect(output).not_to include('"test_excluded"')
+  end
+end