Expose free users to MR approvals feature

- Growth experiment behind the `promote_mr_approvals_in_free` feature
  flag
- Only shown to users who are admins of top-level groups which are
  eligible for trials
- The promo accordion is expanded by default
- The accordion remembers if the user has collapsed it
- Tracking events which help determine the experiment's success

app/assets/stylesheets/utilities.scss

@@ -226,6 +226,16 @@ $gl-line-height-42: px-to-rem(42px);
   max-height: none !important;
 }
 
+// Will be moved to @gitlab/ui in https://gitlab.com/gitlab-org/gitlab-ui/-/issues/1655
+.gl-max-w-62 {
+  max-width: $grid-size * 62;
+}
+
+// Will be moved to @gitlab/ui in https://gitlab.com/gitlab-org/gitlab-ui/-/issues/1655
+.gl-max-w-26 {
+  max-width: $grid-size * 26;
+}
+
 .gl-max-w-50p {
   max-width: 50%;
 }

ee/app/assets/javascripts/approvals/components/mr_edit/free_tier_promo.vue

+<script>
+import { GlAccordion, GlAccordionItem, GlButton, GlLink } from '@gitlab/ui';
+
+export default {
+  components: {
+    GlAccordion,
+    GlAccordionItem,
+    GlButton,
+    GlLink,
+  },
+  inject: ['learnMorePath', 'promoImageAlt', 'promoImagePath', 'tryNowPath'],
+};
+</script>
+
+<template>
+  <div class="gl-mt-2">
+    <p class="gl-mb-0 gl-text-gray-500">
+      {{ __('Approvals are optional.') }}
+    </p>
+
+    <gl-accordion :header-level="3">
+      <gl-accordion-item :title="s__('ApprovalRule|Approval rules')" visible>
+        <h4 class="gl-font-base gl-line-height-20 gl-mt-5 gl-mb-3">
+          {{ s__('ApprovalRule|Add required approvers to improve your code review process') }}
+        </h4>
+        <div class="gl-display-flex">
+          <div class="gl-flex-grow-1 gl-max-w-62 gl-mr-5">
+            <ul class="gl-list-style-position-inside gl-p-0 gl-mb-3">
+              <li>{{ s__('ApprovalRule|Assign approvers by area of expertise.') }}</li>
+              <li>{{ s__('ApprovalRule|Increase your organization’s code quality.') }}</li>
+              <li>{{ s__('ApprovalRule|Reduce the overall time to merge.') }}</li>
+              <li>
+                {{
+                  s__(
+                    'ApprovalRule|Let GitLab designate eligible approvers based on the files changed.',
+                  )
+                }}
+              </li>
+            </ul>
+            <p>
+              <gl-link :href="learnMorePath" target="_blank">
+                {{ s__('ApprovalRule|Learn more about merge request approval.') }}
+              </gl-link>
+            </p>
+            <gl-button category="primary" variant="confirm" :href="tryNowPath" target="_blank">{{
+              s__('ApprovalRule|Try it for free')
+            }}</gl-button>
+          </div>
+          <div class="gl-flex-grow-0 gl-max-w-26 gl-display-none gl-md-display-block">
+            <img :src="promoImagePath" :alt="promoImageAlt" class="svg gl-w-full" />
+          </div>
+        </div>
+      </gl-accordion-item>
+    </gl-accordion>
+  </div>
+</template>

ee/app/assets/javascripts/approvals/mount_mr_promo.js

+import Vue from 'vue';
+import FreeTierPromo from './components/mr_edit/free_tier_promo.vue';
+
+export default function mountApprovalPromo(el) {
+  if (!el) {
+    return null;
+  }
+
+  const { learnMorePath, promoImageAlt, promoImagePath, tryNowPath } = el.dataset;
+
+  return new Vue({
+    el,
+    provide: {
+      learnMorePath,
+      promoImageAlt,
+      promoImagePath,
+      tryNowPath,
+    },
+    render(h) {
+      return h(FreeTierPromo);
+    },
+  });
+}

ee/app/assets/javascripts/pages/projects/merge_requests/shared/init_form.js

 import mountApprovals from 'ee/approvals/mount_mr_edit';
+import mountApprovalsPromo from 'ee/approvals/mount_mr_promo';
 import mountBlockingMergeRequestsInput from 'ee/projects/merge_requests/blocking_mr_input';
 import initCheckFormState from '~/pages/projects/merge_requests/edit/check_form_state';
 
 export default () => {
   const editMrApp = mountApprovals(document.getElementById('js-mr-approvals-input'));
+  mountApprovalsPromo(document.getElementById('js-mr-approvals-promo'));
   mountBlockingMergeRequestsInput(document.getElementById('js-blocking-merge-requests-input'));
 
   if (editMrApp) {

ee/app/views/shared/issuable/_approver_suggestion.haml

@@ -18,3 +18,12 @@
     'project_settings_path': presenter.api_project_approval_settings_path } }
     = sprite_icon('spinner', size: 24, css_class: 'gl-spinner gl-mt-5')
   = render 'projects/merge_requests/code_owner_approval_rules', merge_request: @mr_presenter
+- elsif ::Gitlab::CurrentSettings.should_check_namespace_plan?
+  - top_level_namespace = @target_project.root_ancestor
+  - if can?(current_user, :admin_group, top_level_namespace)
+    - experiment(:promote_mr_approvals_in_free, namespace: top_level_namespace, user: current_user, sticky_to: current_user) do |e|
+      - e.try do
+        #js-mr-approvals-promo{ data: { try_now_path: new_trial_path,
+          learn_more_path: help_page_path('user/project/merge_requests/approvals/index'),
+          promo_image_path: image_path('illustrations/merge_requests.svg'),
+          promo_image_alt: s_('ApprovalRule|A merge request author collaborating with a merge request approver') } }

ee/config/feature_flags/experiment/promote_mr_approvals_in_free.yml

+---
+name: promote_mr_approvals_in_free
+introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/75148
+rollout_issue_url: https://gitlab.com/gitlab-org/gitlab/-/issues/346176
+milestone: '14.6'
+type: experiment
+group: group::conversion
+default_enabled: false

ee/spec/features/merge_request/user_sees_mr_approvals_promo_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe 'user sees MR approvals promo', :js do
+  let_it_be(:user) { create(:user) }
+  let_it_be(:group) { create(:group) }
+  let_it_be(:project) { create(:project, :repository, group: group) }
+
+  before do
+    group.add_owner(user)
+
+    stub_application_setting(check_namespace_plan: true)
+    stub_licensed_features(merge_request_approvers: false)
+    stub_experiments(promote_mr_approvals_in_free: :candidate)
+
+    sign_in(user)
+  end
+
+  describe 'when creating an MR' do
+    before do
+      visit project_new_merge_request_path(project,
+        merge_request: { source_branch: 'fix', target_branch: 'master' }
+      )
+    end
+
+    it 'shows the promo text' do
+      expect(page).to have_text('Add required approvers to improve your code review process')
+    end
+  end
+
+  describe 'when editing an MR' do
+    let_it_be(:merge_request) { create(:merge_request, source_project: project) }
+
+    before do
+      visit edit_project_merge_request_path(project, merge_request)
+    end
+
+    it 'shows the promo text' do
+      expect(page).to have_text('Add required approvers to improve your code review process')
+    end
+  end
+end

ee/spec/frontend/approvals/components/mr_edit/free_tier_promo_spec.js

+import { GlAccordionItem, GlButton, GlLink } from '@gitlab/ui';
+import { shallowMountExtended } from 'helpers/vue_test_utils_helper';
+import { __, s__ } from '~/locale';
+
+import FreeTierPromo from 'ee/approvals/components/mr_edit/free_tier_promo.vue';
+
+describe('PaidFeatureCalloutBadge component', () => {
+  let wrapper;
+
+  const createComponent = (providers = {}) => {
+    return shallowMountExtended(FreeTierPromo, {
+      provide: {
+        learnMorePath: '/learn-more',
+        promoImageAlt: 'some promo image',
+        promoImagePath: '/some-image.svg',
+        tryNowPath: '/try-now',
+        ...providers,
+      },
+    });
+  };
+
+  beforeEach(() => {
+    wrapper = createComponent();
+  });
+
+  afterEach(() => {
+    wrapper.destroy();
+  });
+
+  describe('summary text', () => {
+    it('is rendered correctly', () => {
+      expect(wrapper.findByText(__('Approvals are optional.')).exists()).toBeTruthy();
+    });
+  });
+
+  describe('promo gl-accordion item', () => {
+    let promoItem;
+
+    beforeEach(() => {
+      promoItem = wrapper.findComponent(GlAccordionItem);
+    });
+
+    it('is given the expected title prop', () => {
+      expect(promoItem.props('title')).toBe(s__('ApprovalRule|Approval rules'));
+    });
+
+    it('starts expanded by default', () => {
+      expect(promoItem.props('visible')).toBeTruthy();
+    });
+  });
+
+  describe('promo title', () => {
+    it('is rendered correctly', () => {
+      const promoTitle = wrapper.findByRole('heading', {
+        name: s__('ApprovalRule|Add required approvers to improve your code review process'),
+      });
+
+      expect(promoTitle.exists()).toBeTruthy();
+    });
+  });
+
+  describe('promo value statements list', () => {
+    it('contains the expected statements', () => {
+      const statementItemTexts = wrapper.findAllByRole('listitem').wrappers.map((li) => li.text());
+
+      expect(statementItemTexts).toEqual([
+        s__('ApprovalRule|Assign approvers by area of expertise.'),
+        s__('ApprovalRule|Increase your organization’s code quality.'),
+        s__('ApprovalRule|Reduce the overall time to merge.'),
+        s__('ApprovalRule|Let GitLab designate eligible approvers based on the files changed.'),
+      ]);
+    });
+  });
+
+  describe('"Learn More" link', () => {
+    let learnMoreLink;
+
+    beforeEach(() => {
+      learnMoreLink = wrapper.findComponent(GlLink);
+    });
+
+    it('has correct href', () => {
+      expect(learnMoreLink.attributes('href')).toBe('/learn-more');
+    });
+
+    it('has correct text', () => {
+      expect(learnMoreLink.text()).toBe(
+        s__('ApprovalRule|Learn more about merge request approval.'),
+      );
+    });
+  });
+
+  describe('"Try Now" button', () => {
+    let tryNowBtn;
+
+    beforeEach(() => {
+      tryNowBtn = wrapper.findComponent(GlButton);
+    });
+
+    it('has correct href', () => {
+      expect(tryNowBtn.attributes('href')).toBe('/try-now');
+    });
+
+    it('has correct text', () => {
+      expect(tryNowBtn.text()).toBe(s__('ApprovalRule|Try it for free'));
+    });
+  });
+
+  describe('promo image', () => {
+    it('has correct src', () => {
+      const promoImage = wrapper.findByAltText('some promo image');
+
+      expect(promoImage.attributes('src')).toBe('/some-image.svg');
+    });
+  });
+});

ee/spec/views/shared/issuable/_approver_suggestion.html.haml_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe 'shared/issuable/_approver_suggestion.html.haml' do
+  let_it_be(:merge_request) { create(:merge_request) }
+  let_it_be(:user) { merge_request.author }
+  let_it_be(:presenter) { merge_request.present(current_user: user) }
+
+  let(:approvals_available) { true }
+
+  before do
+    allow(view).to receive(:can?).with(user, :update_approvers, merge_request).and_return(true)
+    allow(view).to receive(:current_user).and_return(user)
+    allow(presenter).to receive(:approval_feature_available?).and_return(approvals_available)
+
+    assign(:target_project, merge_request.target_project)
+  end
+
+  def do_render
+    render 'shared/issuable/approver_suggestion', issuable: merge_request, presenter: presenter
+  end
+
+  context 'when the approval feature is enabled' do
+    let(:approvals_available) { true }
+
+    before do
+      assign(:mr_presenter, presenter)
+
+      # used inside the projects/merge_requests/_code_owner_approval_rules partial
+      assign(:project, merge_request.target_project)
+    end
+
+    it 'renders the MR approvals promo' do
+      do_render
+
+      expect(rendered).to have_css('#js-mr-approvals-input')
+      expect(view).to render_template('projects/merge_requests/_code_owner_approval_rules')
+    end
+  end
+
+  context 'when the approval feature is not enabled' do
+    let(:approvals_available) { false }
+
+    before do
+      stub_application_setting(check_namespace_plan: check_namespace_plan)
+    end
+
+    context 'when the check_namespace_plan setting is on' do
+      let(:check_namespace_plan) { true }
+
+      before do
+        allow(view).to receive(:can?).with(user, :admin_group, anything).and_return(user_can_admin_group)
+      end
+
+      context 'when the user is an owner of the root group' do
+        let(:user_can_admin_group) { true }
+
+        before do
+          stub_experiments(promote_mr_approvals_in_free: experiment_variant)
+        end
+
+        context 'when the user is in the promote_mr_approvals_in_free experiment' do
+          let(:experiment_variant) { :candidate }
+
+          it 'renders the MR approvals promo' do
+            do_render
+
+            expect(rendered).to have_css('#js-mr-approvals-promo')
+          end
+        end
+
+        context 'when the user is not in the promote_mr_approvals_in_free experiment' do
+          let(:experiment_variant) { :control }
+
+          it 'renders nothing' do
+            do_render
+
+            expect(rendered).to be_blank
+          end
+        end
+      end
+
+      context 'when the user is not an owner of the root group' do
+        let(:user_can_admin_group) { false }
+
+        it 'renders nothing' do
+          do_render
+
+          expect(rendered).to be_blank
+        end
+      end
+    end
+
+    context 'when the check_namespace_plan setting is off' do
+      let(:check_namespace_plan) { false }
+
+      it 'renders nothing' do
+        do_render
+
+        expect(rendered).to be_blank
+      end
+    end
+  end
+end

locale/gitlab.pot

@@ -4353,9 +4353,15 @@ msgstr[1] ""
 msgid "ApprovalRule|%{firstLabel} +%{numberOfAdditionalLabels} more"
 msgstr ""
 
+msgid "ApprovalRule|A merge request author collaborating with a merge request approver"
+msgstr ""
+
 msgid "ApprovalRule|Add approvers"
 msgstr ""
 
+msgid "ApprovalRule|Add required approvers to improve your code review process"
+msgstr ""
+
 msgid "ApprovalRule|All scanners"
 msgstr ""
 
@@ -4386,6 +4392,9 @@ msgstr ""
 msgid "ApprovalRule|Approvers"
 msgstr ""
 
+msgid "ApprovalRule|Assign approvers by area of expertise."
+msgstr ""
+
 msgid "ApprovalRule|Confirmed"
 msgstr ""
 
@@ -4395,6 +4404,15 @@ msgstr ""
 msgid "ApprovalRule|Examples: QA, Security."
 msgstr ""
 
+msgid "ApprovalRule|Increase your organization’s code quality."
+msgstr ""
+
+msgid "ApprovalRule|Learn more about merge request approval."
+msgstr ""
+
+msgid "ApprovalRule|Let GitLab designate eligible approvers based on the files changed."
+msgstr ""
+
 msgid "ApprovalRule|Name"
 msgstr ""
 
@@ -4419,6 +4437,9 @@ msgstr ""
 msgid "ApprovalRule|Previously detected"
 msgstr ""
 
+msgid "ApprovalRule|Reduce the overall time to merge."
+msgstr ""
+
 msgid "ApprovalRule|Resolved"
 msgstr ""
 
@@ -4446,6 +4467,9 @@ msgstr ""
 msgid "ApprovalRule|Target branch"
 msgstr ""
 
+msgid "ApprovalRule|Try it for free"
+msgstr ""
+
 msgid "ApprovalRule|Vulnerabilities allowed"
 msgstr ""