Add vue components for reviewers in sidebar widget

Issue: https://gitlab.com/gitlab-org/gitlab/-/issues/237921

- This is part 2 of 2.
- In this MR, we will be adding the necessary vue components of adding
reviewers in the sidebar widget.

app/assets/javascripts/sidebar/components/reviewers/collapsed_reviewer.vue

+<script>
+// NOTE! For the first iteration, we are simply copying the implementation of Assignees
+// It will soon be overhauled in Issue https://gitlab.com/gitlab-org/gitlab/-/issues/233736
+import ReviewerAvatar from './reviewer_avatar.vue';
+
+export default {
+  components: {
+    ReviewerAvatar,
+  },
+  props: {
+    user: {
+      type: Object,
+      required: true,
+    },
+  },
+};
+</script>
+
+<template>
+  <button type="button" class="btn-link">
+    <reviewer-avatar :user="user" :img-size="24" />
+    <span class="author"> {{ user.name }} </span>
+  </button>
+</template>

app/assets/javascripts/sidebar/components/reviewers/collapsed_reviewer_list.vue

+<script>
+// NOTE! For the first iteration, we are simply copying the implementation of Assignees
+// It will soon be overhauled in Issue https://gitlab.com/gitlab-org/gitlab/-/issues/233736
+import { GlIcon, GlTooltipDirective } from '@gitlab/ui';
+import { __, sprintf } from '~/locale';
+import CollapsedReviewer from './collapsed_reviewer.vue';
+
+const DEFAULT_MAX_COUNTER = 99;
+const DEFAULT_RENDER_COUNT = 5;
+
+export default {
+  directives: {
+    GlTooltip: GlTooltipDirective,
+  },
+  components: {
+    CollapsedReviewer,
+    GlIcon,
+  },
+  props: {
+    users: {
+      type: Array,
+      required: true,
+    },
+  },
+  computed: {
+    hasNoUsers() {
+      return !this.users.length;
+    },
+    hasMoreThanOneReviewer() {
+      return this.users.length > 1;
+    },
+    hasMoreThanTwoReviewers() {
+      return this.users.length > 2;
+    },
+    allReviewersCanMerge() {
+      return this.users.every(user => user.can_merge);
+    },
+    sidebarAvatarCounter() {
+      if (this.users.length > DEFAULT_MAX_COUNTER) {
+        return `${DEFAULT_MAX_COUNTER}+`;
+      }
+
+      return `+${this.users.length - 1}`;
+    },
+    collapsedUsers() {
+      const collapsedLength = this.hasMoreThanTwoReviewers ? 1 : this.users.length;
+
+      return this.users.slice(0, collapsedLength);
+    },
+    tooltipTitleMergeStatus() {
+      const mergeLength = this.users.filter(u => u.can_merge).length;
+
+      if (mergeLength === this.users.length) {
+        return '';
+      } else if (mergeLength > 0) {
+        return sprintf(__('%{mergeLength}/%{usersLength} can merge'), {
+          mergeLength,
+          usersLength: this.users.length,
+        });
+      }
+
+      return this.users.length === 1 ? __('cannot merge') : __('no one can merge');
+    },
+    tooltipTitle() {
+      const maxRender = Math.min(DEFAULT_RENDER_COUNT, this.users.length);
+      const renderUsers = this.users.slice(0, maxRender);
+      const names = renderUsers.map(u => u.name);
+
+      if (!this.users.length) {
+        return __('Reviewer(s)');
+      }
+
+      if (this.users.length > names.length) {
+        names.push(sprintf(__('+ %{amount} more'), { amount: this.users.length - names.length }));
+      }
+
+      const text = names.join(', ');
+
+      return this.tooltipTitleMergeStatus ? `${text} (${this.tooltipTitleMergeStatus})` : text;
+    },
+
+    tooltipOptions() {
+      return { container: 'body', placement: 'left', boundary: 'viewport' };
+    },
+  },
+};
+</script>
+
+<template>
+  <div
+    v-gl-tooltip="tooltipOptions"
+    :class="{ 'multiple-users': hasMoreThanOneReviewer }"
+    :title="tooltipTitle"
+    class="sidebar-collapsed-icon sidebar-collapsed-user"
+  >
+    <gl-icon v-if="hasNoUsers" name="user" :aria-label="__('None')" />
+    <collapsed-reviewer v-for="user in collapsedUsers" :key="user.id" :user="user" />
+    <button v-if="hasMoreThanTwoReviewers" class="btn-link" type="button">
+      <span class="avatar-counter sidebar-avatar-counter"> {{ sidebarAvatarCounter }} </span>
+      <i
+        v-if="!allReviewersCanMerge"
+        aria-hidden="true"
+        class="fa fa-exclamation-triangle merge-icon"
+      ></i>
+    </button>
+  </div>
+</template>

app/assets/javascripts/sidebar/components/reviewers/reviewer_avatar.vue

+<script>
+// NOTE! For the first iteration, we are simply copying the implementation of Assignees
+// It will soon be overhauled in Issue https://gitlab.com/gitlab-org/gitlab/-/issues/233736
+import { __, sprintf } from '~/locale';
+
+export default {
+  props: {
+    user: {
+      type: Object,
+      required: true,
+    },
+    imgSize: {
+      type: Number,
+      required: true,
+    },
+  },
+  computed: {
+    reviewerAlt() {
+      return sprintf(__("%{userName}'s avatar"), { userName: this.user.name });
+    },
+    avatarUrl() {
+      return this.user.avatar || this.user.avatar_url || gon.default_avatar_url;
+    },
+    hasMergeIcon() {
+      return !this.user.can_merge;
+    },
+  },
+};
+</script>
+
+<template>
+  <span class="position-relative">
+    <img
+      :alt="reviewerAlt"
+      :src="avatarUrl"
+      :width="imgSize"
+      :class="`s${imgSize}`"
+      class="avatar avatar-inline m-0"
+      data-qa-selector="avatar_image"
+    />
+    <i v-if="hasMergeIcon" aria-hidden="true" class="fa fa-exclamation-triangle merge-icon"></i>
+  </span>
+</template>

app/assets/javascripts/sidebar/components/reviewers/reviewer_avatar_link.vue

+<script>
+// NOTE! For the first iteration, we are simply copying the implementation of Assignees
+// It will soon be overhauled in Issue https://gitlab.com/gitlab-org/gitlab/-/issues/233736
+import { GlTooltipDirective, GlLink } from '@gitlab/ui';
+import { __, sprintf } from '~/locale';
+import ReviewerAvatar from './reviewer_avatar.vue';
+
+export default {
+  components: {
+    ReviewerAvatar,
+    GlLink,
+  },
+  directives: {
+    GlTooltip: GlTooltipDirective,
+  },
+  props: {
+    user: {
+      type: Object,
+      required: true,
+    },
+    rootPath: {
+      type: String,
+      required: true,
+    },
+    tooltipPlacement: {
+      type: String,
+      default: 'bottom',
+      required: false,
+    },
+    tooltipHasName: {
+      type: Boolean,
+      default: true,
+      required: false,
+    },
+    issuableType: {
+      type: String,
+      default: 'issue',
+      required: false,
+    },
+  },
+  computed: {
+    cannotMerge() {
+      return this.issuableType === 'merge_request' && !this.user.can_merge;
+    },
+    tooltipTitle() {
+      if (this.cannotMerge && this.tooltipHasName) {
+        return sprintf(__('%{userName} (cannot merge)'), { userName: this.user.name });
+      } else if (this.cannotMerge) {
+        return __('Cannot merge');
+      } else if (this.tooltipHasName) {
+        return this.user.name;
+      }
+
+      return '';
+    },
+    tooltipOption() {
+      return {
+        container: 'body',
+        placement: this.tooltipPlacement,
+        boundary: 'viewport',
+      };
+    },
+    reviewerUrl() {
+      return this.user.web_url;
+    },
+  },
+};
+</script>
+
+<template>
+  <!-- must be `d-inline-block` or parent flex-basis causes width issues -->
+  <gl-link
+    v-gl-tooltip="tooltipOption"
+    :href="reviewerUrl"
+    :title="tooltipTitle"
+    class="d-inline-block"
+  >
+    <!-- use d-flex so that slot can be appropriately styled -->
+    <span class="d-flex">
+      <reviewer-avatar :user="user" :img-size="32" :issuable-type="issuableType" />
+      <slot :user="user"></slot>
+    </span>
+  </gl-link>
+</template>

app/assets/javascripts/sidebar/components/reviewers/reviewer_title.vue

+<script>
+// NOTE! For the first iteration, we are simply copying the implementation of Assignees
+// It will soon be overhauled in Issue https://gitlab.com/gitlab-org/gitlab/-/issues/233736
+import { GlLoadingIcon } from '@gitlab/ui';
+import { n__ } from '~/locale';
+
+export default {
+  name: 'ReviewerTitle',
+  components: {
+    GlLoadingIcon,
+  },
+  props: {
+    loading: {
+      type: Boolean,
+      required: false,
+      default: false,
+    },
+    numberOfReviewers: {
+      type: Number,
+      required: true,
+    },
+    editable: {
+      type: Boolean,
+      required: true,
+    },
+    showToggle: {
+      type: Boolean,
+      required: false,
+      default: false,
+    },
+  },
+  computed: {
+    reviewerTitle() {
+      const reviewers = this.numberOfReviewers;
+      return n__('Reviewer', `%d Reviewers`, reviewers);
+    },
+  },
+};
+</script>
+<template>
+  <div class="title hide-collapsed">
+    {{ reviewerTitle }}
+    <gl-loading-icon v-if="loading" inline class="align-bottom" />
+    <a
+      v-if="editable"
+      class="js-sidebar-dropdown-toggle edit-link float-right"
+      href="#"
+      data-track-event="click_edit_button"
+      data-track-label="right_sidebar"
+      data-track-property="reviewer"
+    >
+      {{ __('Edit') }}
+    </a>
+    <a
+      v-if="showToggle"
+      :aria-label="__('Toggle sidebar')"
+      class="gutter-toggle float-right js-sidebar-toggle"
+      href="#"
+      role="button"
+    >
+      <i aria-hidden="true" data-hidden="true" class="fa fa-angle-double-right"></i>
+    </a>
+  </div>
+</template>

app/assets/javascripts/sidebar/components/reviewers/reviewers.vue

+<script>
+// NOTE! For the first iteration, we are simply copying the implementation of Assignees
+// It will soon be overhauled in Issue https://gitlab.com/gitlab-org/gitlab/-/issues/233736
+import CollapsedReviewerList from './collapsed_reviewer_list.vue';
+import UncollapsedReviewerList from './uncollapsed_reviewer_list.vue';
+
+export default {
+  // name: 'Reviewers' is a false positive: https://gitlab.com/gitlab-org/frontend/eslint-plugin-i18n/issues/26#possible-false-positives
+  // eslint-disable-next-line @gitlab/require-i18n-strings
+  name: 'Reviewers',
+  components: {
+    CollapsedReviewerList,
+    UncollapsedReviewerList,
+  },
+  props: {
+    rootPath: {
+      type: String,
+      required: true,
+    },
+    users: {
+      type: Array,
+      required: true,
+    },
+    editable: {
+      type: Boolean,
+      required: true,
+    },
+    issuableType: {
+      type: String,
+      required: false,
+      default: 'issue',
+    },
+  },
+  computed: {
+    hasNoUsers() {
+      return !this.users.length;
+    },
+    sortedReviewers() {
+      const canMergeUsers = this.users.filter(user => user.can_merge);
+      const canNotMergeUsers = this.users.filter(user => !user.can_merge);
+
+      return [...canMergeUsers, ...canNotMergeUsers];
+    },
+  },
+  methods: {
+    assignSelf() {
+      this.$emit('assign-self');
+    },
+  },
+};
+</script>
+
+<template>
+  <div>
+    <collapsed-reviewer-list :users="sortedReviewers" :issuable-type="issuableType" />
+
+    <div class="value hide-collapsed">
+      <template v-if="hasNoUsers">
+        <span class="assign-yourself no-value qa-assign-yourself">
+          {{ __('None') }}
+        </span>
+      </template>
+
+      <uncollapsed-reviewer-list
+        v-else
+        :users="sortedReviewers"
+        :root-path="rootPath"
+        :issuable-type="issuableType"
+      />
+    </div>
+  </div>
+</template>

app/assets/javascripts/sidebar/components/reviewers/sidebar_reviewers.vue

+<script>
+// NOTE! For the first iteration, we are simply copying the implementation of Assignees
+// It will soon be overhauled in Issue https://gitlab.com/gitlab-org/gitlab/-/issues/233736
+import { deprecatedCreateFlash as Flash } from '~/flash';
+import eventHub from '~/sidebar/event_hub';
+import Store from '~/sidebar/stores/sidebar_store';
+import glFeatureFlagsMixin from '~/vue_shared/mixins/gl_feature_flags_mixin';
+import ReviewerTitle from './reviewer_title.vue';
+import Reviewers from './reviewers.vue';
+import { __ } from '~/locale';
+
+export default {
+  name: 'SidebarReviewers',
+  components: {
+    ReviewerTitle,
+    Reviewers,
+  },
+  mixins: [glFeatureFlagsMixin()],
+  props: {
+    mediator: {
+      type: Object,
+      required: true,
+    },
+    field: {
+      type: String,
+      required: true,
+    },
+    signedIn: {
+      type: Boolean,
+      required: false,
+      default: false,
+    },
+    issuableType: {
+      type: String,
+      required: false,
+      default: 'issue',
+    },
+    issuableIid: {
+      type: String,
+      required: true,
+    },
+    projectPath: {
+      type: String,
+      required: true,
+    },
+  },
+  data() {
+    return {
+      store: new Store(),
+      loading: false,
+    };
+  },
+  created() {
+    this.removeReviewer = this.store.removeReviewer.bind(this.store);
+    this.addReviewer = this.store.addReviewer.bind(this.store);
+    this.removeAllReviewers = this.store.removeAllReviewers.bind(this.store);
+
+    // Get events from deprecatedJQueryDropdown
+    eventHub.$on('sidebar.removeReviewer', this.removeReviewer);
+    eventHub.$on('sidebar.addReviewer', this.addReviewer);
+    eventHub.$on('sidebar.removeAllReviewers', this.removeAllReviewers);
+    eventHub.$on('sidebar.saveReviewers', this.saveReviewers);
+  },
+  beforeDestroy() {
+    eventHub.$off('sidebar.removeReviewer', this.removeReviewer);
+    eventHub.$off('sidebar.addReviewer', this.addReviewer);
+    eventHub.$off('sidebar.removeAllReviewers', this.removeAllReviewers);
+    eventHub.$off('sidebar.saveReviewers', this.saveReviewers);
+  },
+  methods: {
+    saveReviewers() {
+      this.loading = true;
+
+      this.mediator
+        .saveReviewers(this.field)
+        .then(() => {
+          this.loading = false;
+          // Uncomment once this issue has been addressed > https://gitlab.com/gitlab-org/gitlab/-/issues/237922
+          // refreshUserMergeRequestCounts();
+        })
+        .catch(() => {
+          this.loading = false;
+          return new Flash(__('Error occurred when saving reviewers'));
+        });
+    },
+  },
+};
+</script>
+
+<template>
+  <div>
+    <reviewer-title
+      :number-of-reviewers="store.reviewers.length"
+      :loading="loading || store.isFetching.reviewers"
+      :editable="store.editable"
+      :show-toggle="!signedIn"
+    />
+    <reviewers
+      v-if="!store.isFetching.reviewers"
+      :root-path="store.rootPath"
+      :users="store.reviewers"
+      :editable="store.editable"
+      :issuable-type="issuableType"
+      class="value"
+    />
+  </div>
+</template>

app/assets/javascripts/sidebar/components/reviewers/uncollapsed_reviewer_list.vue

+<script>
+// NOTE! For the first iteration, we are simply copying the implementation of Assignees
+// It will soon be overhauled in Issue https://gitlab.com/gitlab-org/gitlab/-/issues/233736
+import { __, sprintf } from '~/locale';
+import ReviewerAvatarLink from './reviewer_avatar_link.vue';
+
+const DEFAULT_RENDER_COUNT = 5;
+
+export default {
+  components: {
+    ReviewerAvatarLink,
+  },
+  props: {
+    users: {
+      type: Array,
+      required: true,
+    },
+    rootPath: {
+      type: String,
+      required: true,
+    },
+    issuableType: {
+      type: String,
+      required: false,
+      default: 'issue',
+    },
+  },
+  data() {
+    return {
+      showLess: true,
+    };
+  },
+  computed: {
+    firstUser() {
+      return this.users[0];
+    },
+    hasOneUser() {
+      return this.users.length === 1;
+    },
+    hiddenReviewersLabel() {
+      const { numberOfHiddenReviewers } = this;
+      return sprintf(__('+ %{numberOfHiddenReviewers} more'), { numberOfHiddenReviewers });
+    },
+    renderShowMoreSection() {
+      return this.users.length > DEFAULT_RENDER_COUNT;
+    },
+    numberOfHiddenReviewers() {
+      return this.users.length - DEFAULT_RENDER_COUNT;
+    },
+    uncollapsedUsers() {
+      const uncollapsedLength = this.showLess
+        ? Math.min(this.users.length, DEFAULT_RENDER_COUNT)
+        : this.users.length;
+      return this.showLess ? this.users.slice(0, uncollapsedLength) : this.users;
+    },
+    username() {
+      return `@${this.firstUser.username}`;
+    },
+  },
+  methods: {
+    toggleShowLess() {
+      this.showLess = !this.showLess;
+    },
+  },
+};
+</script>
+
+<template>
+  <reviewer-avatar-link
+    v-if="hasOneUser"
+    #default="{ user }"
+    tooltip-placement="left"
+    :tooltip-has-name="false"
+    :user="firstUser"
+    :root-path="rootPath"
+    :issuable-type="issuableType"
+  >
+    <div class="ml-2">
+      <span class="author"> {{ user.name }} </span>
+      <span class="username"> {{ username }} </span>
+    </div>
+  </reviewer-avatar-link>
+  <div v-else>
+    <div class="user-list">
+      <div v-for="user in uncollapsedUsers" :key="user.id" class="user-item">
+        <reviewer-avatar-link :user="user" :root-path="rootPath" :issuable-type="issuableType" />
+      </div>
+    </div>
+    <div v-if="renderShowMoreSection" class="user-list-more">
+      <button
+        type="button"
+        class="btn-link"
+        data-qa-selector="more_reviewers_link"
+        @click="toggleShowLess"
+      >
+        <template v-if="showLess">
+          {{ hiddenReviewersLabel }}
+        </template>
+        <template v-else>{{ __('- show less') }}</template>
+      </button>
+    </div>
+  </div>
+</template>

app/assets/javascripts/sidebar/mount_sidebar.js

@@ -5,6 +5,7 @@ import Vuex from 'vuex';
 import SidebarTimeTracking from './components/time_tracking/sidebar_time_tracking.vue';
 import SidebarAssignees from './components/assignees/sidebar_assignees.vue';
 import SidebarLabels from './components/labels/sidebar_labels.vue';
+import SidebarReviewers from './components/reviewers/sidebar_reviewers.vue';
 import ConfidentialIssueSidebar from './components/confidential/confidential_issue_sidebar.vue';
 import SidebarMoveIssue from './lib/sidebar_move_issue';
 import IssuableLockForm from './components/lock/issuable_lock_form.vue';
@@ -56,6 +57,36 @@ function mountAssigneesComponent(mediator) {
   });
 }
 
+function mountReviewersComponent(mediator) {
+  const el = document.getElementById('js-vue-sidebar-reviewers');
+  const apolloProvider = new VueApollo({
+    defaultClient: createDefaultClient(),
+  });
+
+  if (!el) return;
+
+  const { iid, fullPath } = getSidebarOptions();
+  // eslint-disable-next-line no-new
+  new Vue({
+    el,
+    apolloProvider,
+    components: {
+      SidebarReviewers,
+    },
+    render: createElement =>
+      createElement('sidebar-reviewers', {
+        props: {
+          mediator,
+          issuableIid: String(iid),
+          projectPath: fullPath,
+          field: el.dataset.field,
+          signedIn: el.hasAttribute('data-signed-in'),
+          issuableType: isInIssuePage() ? 'issue' : 'merge_request',
+        },
+      }),
+  });
+}
+
 export function mountSidebarLabels() {
   const el = document.querySelector('.js-sidebar-labels');
 
@@ -245,6 +276,7 @@ function mountSeverityComponent() {
 
 export function mountSidebar(mediator) {
   mountAssigneesComponent(mediator);
+  mountReviewersComponent(mediator);
   mountConfidentialComponent(mediator);
   mountLockComponent();
   mountParticipantsComponent(mediator);

app/assets/stylesheets/pages/issuable.scss

@@ -117,7 +117,8 @@
   }
 }
 
-.assignee {
+.assignee,
+.reviewer {
   .merge-icon {
     color: $orange-400;
     position: absolute;

app/views/shared/issuable/_sidebar.html.haml

@@ -5,6 +5,7 @@
 - signed_in = !!issuable_sidebar.dig(:current_user, :id)
 - can_edit_issuable = issuable_sidebar.dig(:current_user, :can_edit)
 - add_page_startup_api_call "#{issuable_sidebar[:issuable_json_path]}?serializer=sidebar_extras"
+- reviewers = local_assigns.fetch(:reviewers, nil)
 
 - if Feature.enabled?(:vue_issuable_sidebar, @project.group)
   %aside#js-vue-issuable-sidebar{ data: { signed_in: signed_in,
@@ -28,6 +29,10 @@
         .block.assignee.qa-assignee-block
           = render "shared/issuable/sidebar_assignees", issuable_sidebar: issuable_sidebar, assignees: assignees
 
+        - if Feature.enabled?(:merge_request_reviewers, @project) && reviewers
+          .block.reviewer.qa-reviewer-block
+            = render "shared/issuable/sidebar_reviewers", issuable_sidebar: issuable_sidebar, reviewers: reviewers
+
         = render_if_exists 'shared/issuable/sidebar_item_epic', issuable_sidebar: issuable_sidebar
 
         - if issuable_sidebar[:supports_milestone]

locale/gitlab.pot

@@ -977,6 +977,9 @@ msgstr ""
 msgid "+ %{numberOfHiddenAssignees} more"
 msgstr ""
 
+msgid "+ %{numberOfHiddenReviewers} more"
+msgstr ""
+
 msgid "+%d more"
 msgid_plural "+%d more"
 msgstr[0] ""
@@ -10223,6 +10226,9 @@ msgstr ""
 msgid "Error occurred when saving assignees"
 msgstr ""
 
+msgid "Error occurred when saving reviewers"
+msgstr ""
+
 msgid "Error occurred when toggling the notification subscription"
 msgstr ""
 
@@ -21987,6 +21993,11 @@ msgid "ReviewApp|Enable Review App"
 msgstr ""
 
 msgid "Reviewer"
+msgid_plural "%d Reviewers"
+msgstr[0] ""
+msgstr[1] ""
+
+msgid "Reviewer(s)"
 msgstr ""
 
 msgid "Reviewing"

spec/features/merge_request/user_edits_mr_spec.rb

@@ -21,24 +21,6 @@ RSpec.describe 'Merge request > User edits MR' do
     it_behaves_like 'an editable merge request'
   end
 
-  context 'when merge_request_reviewers is turned on' do
-    before do
-      stub_feature_flags(merge_request_reviewers: true)
-    end
-
-    context 'non-fork merge request' do
-      include_context 'merge request edit context'
-      it_behaves_like 'an editable merge request with reviewers'
-    end
-
-    context 'for a forked project' do
-      let(:source_project) { fork_project(target_project, nil, repository: true) }
-
-      include_context 'merge request edit context'
-      it_behaves_like 'an editable merge request with reviewers'
-    end
-  end
-
   context 'when merge_request_reviewers is turned off' do
     before do
       stub_feature_flags(merge_request_reviewers: false)

spec/features/merge_request/user_views_open_merge_request_spec.rb

@@ -24,6 +24,23 @@ RSpec.describe 'User views an open merge request' do
 
       expect(page).to have_content(merge_request.title)
     end
+
+    it 'has reviewers in sidebar' do
+      expect(page).to have_css('.reviewer')
+    end
+  end
+
+  context 'when merge_request_reviewers is turned off' do
+    let(:project) { create(:project, :public, :repository) }
+
+    before do
+      stub_feature_flags(merge_request_reviewers: false)
+      visit(merge_request_path(merge_request))
+    end
+
+    it 'has reviewers in sidebar' do
+      expect(page).not_to have_css('.reviewer')
+    end
   end
 
   context 'when a merge request has repository', :js do

spec/frontend/sidebar/reviewer_title_spec.js

+import { shallowMount } from '@vue/test-utils';
+import { GlLoadingIcon } from '@gitlab/ui';
+import { mockTracking, triggerEvent } from 'helpers/tracking_helper';
+import Component from '~/sidebar/components/reviewers/reviewer_title.vue';
+
+describe('ReviewerTitle component', () => {
+  let wrapper;
+
+  const createComponent = props => {
+    return shallowMount(Component, {
+      propsData: {
+        numberOfReviewers: 0,
+        editable: false,
+        ...props,
+      },
+    });
+  };
+
+  afterEach(() => {
+    wrapper.destroy();
+    wrapper = null;
+  });
+
+  describe('reviewer title', () => {
+    it('renders reviewer', () => {
+      wrapper = createComponent({
+        numberOfReviewers: 1,
+        editable: false,
+      });
+
+      expect(wrapper.vm.$el.innerText.trim()).toEqual('Reviewer');
+    });
+
+    it('renders 2 reviewers', () => {
+      wrapper = createComponent({
+        numberOfReviewers: 2,
+        editable: false,
+      });
+
+      expect(wrapper.vm.$el.innerText.trim()).toEqual('2 Reviewers');
+    });
+  });
+
+  describe('gutter toggle', () => {
+    it('does not show toggle by default', () => {
+      wrapper = createComponent({
+        numberOfReviewers: 2,
+        editable: false,
+      });
+
+      expect(wrapper.vm.$el.querySelector('.gutter-toggle')).toBeNull();
+    });
+
+    it('shows toggle when showToggle is true', () => {
+      wrapper = createComponent({
+        numberOfReviewers: 2,
+        editable: false,
+        showToggle: true,
+      });
+
+      expect(wrapper.vm.$el.querySelector('.gutter-toggle')).toEqual(expect.any(Object));
+    });
+  });
+
+  it('does not render spinner by default', () => {
+    wrapper = createComponent({
+      numberOfReviewers: 0,
+      editable: false,
+    });
+
+    expect(wrapper.find(GlLoadingIcon).exists()).toBeFalsy();
+  });
+
+  it('renders spinner when loading', () => {
+    wrapper = createComponent({
+      loading: true,
+      numberOfReviewers: 0,
+      editable: false,
+    });
+
+    expect(wrapper.find(GlLoadingIcon).exists()).toBeTruthy();
+  });
+
+  it('does not render edit link when not editable', () => {
+    wrapper = createComponent({
+      numberOfReviewers: 0,
+      editable: false,
+    });
+
+    expect(wrapper.vm.$el.querySelector('.edit-link')).toBeNull();
+  });
+
+  it('renders edit link when editable', () => {
+    wrapper = createComponent({
+      numberOfReviewers: 0,
+      editable: true,
+    });
+
+    expect(wrapper.vm.$el.querySelector('.edit-link')).not.toBeNull();
+  });
+
+  it('tracks the event when edit is clicked', () => {
+    wrapper = createComponent({
+      numberOfReviewers: 0,
+      editable: true,
+    });
+
+    const spy = mockTracking('_category_', wrapper.element, jest.spyOn);
+    triggerEvent('.js-sidebar-dropdown-toggle');
+
+    expect(spy).toHaveBeenCalledWith('_category_', 'click_edit_button', {
+      label: 'right_sidebar',
+      property: 'reviewer',
+    });
+  });
+});

spec/frontend/sidebar/reviewers_spec.js

+import { mount } from '@vue/test-utils';
+import { trimText } from 'helpers/text_helper';
+import { GlIcon } from '@gitlab/ui';
+import Reviewer from '~/sidebar/components/reviewers/reviewers.vue';
+import UsersMock from './mock_data';
+import UsersMockHelper from '../helpers/user_mock_data_helper';
+
+describe('Reviewer component', () => {
+  const getDefaultProps = () => ({
+    rootPath: 'http://localhost:3000',
+    users: [],
+    editable: false,
+  });
+  let wrapper;
+
+  const createWrapper = (propsData = getDefaultProps()) => {
+    wrapper = mount(Reviewer, {
+      propsData,
+    });
+  };
+
+  const findCollapsedChildren = () => wrapper.findAll('.sidebar-collapsed-icon > *');
+
+  afterEach(() => {
+    wrapper.destroy();
+  });
+
+  describe('No reviewers/users', () => {
+    it('displays no reviewer icon when collapsed', () => {
+      createWrapper();
+      const collapsedChildren = findCollapsedChildren();
+      const userIcon = collapsedChildren.at(0).find(GlIcon);
+
+      expect(collapsedChildren.length).toBe(1);
+      expect(collapsedChildren.at(0).attributes('aria-label')).toBe('None');
+      expect(userIcon.exists()).toBe(true);
+      expect(userIcon.props('name')).toBe('user');
+    });
+  });
+
+  describe('One reviewer/user', () => {
+    it('displays one reviewer icon when collapsed', () => {
+      createWrapper({
+        ...getDefaultProps(),
+        users: [UsersMock.user],
+      });
+
+      const collapsedChildren = findCollapsedChildren();
+      const reviewer = collapsedChildren.at(0);
+
+      expect(collapsedChildren.length).toBe(1);
+      expect(reviewer.find('.avatar').attributes('src')).toBe(UsersMock.user.avatar);
+      expect(reviewer.find('.avatar').attributes('alt')).toBe(`${UsersMock.user.name}'s avatar`);
+
+      expect(trimText(reviewer.find('.author').text())).toBe(UsersMock.user.name);
+    });
+  });
+
+  describe('Two or more reviewers/users', () => {
+    it('displays two reviewer icons when collapsed', () => {
+      const users = UsersMockHelper.createNumberRandomUsers(2);
+      createWrapper({
+        ...getDefaultProps(),
+        users,
+      });
+
+      const collapsedChildren = findCollapsedChildren();
+
+      expect(collapsedChildren.length).toBe(2);
+
+      const first = collapsedChildren.at(0);
+
+      expect(first.find('.avatar').attributes('src')).toBe(users[0].avatar_url);
+      expect(first.find('.avatar').attributes('alt')).toBe(`${users[0].name}'s avatar`);
+
+      expect(trimText(first.find('.author').text())).toBe(users[0].name);
+
+      const second = collapsedChildren.at(1);
+
+      expect(second.find('.avatar').attributes('src')).toBe(users[1].avatar_url);
+      expect(second.find('.avatar').attributes('alt')).toBe(`${users[1].name}'s avatar`);
+
+      expect(trimText(second.find('.author').text())).toBe(users[1].name);
+    });
+
+    it('displays one reviewer icon and counter when collapsed', () => {
+      const users = UsersMockHelper.createNumberRandomUsers(3);
+      createWrapper({
+        ...getDefaultProps(),
+        users,
+      });
+
+      const collapsedChildren = findCollapsedChildren();
+
+      expect(collapsedChildren.length).toBe(2);
+
+      const first = collapsedChildren.at(0);
+
+      expect(first.find('.avatar').attributes('src')).toBe(users[0].avatar_url);
+      expect(first.find('.avatar').attributes('alt')).toBe(`${users[0].name}'s avatar`);
+
+      expect(trimText(first.find('.author').text())).toBe(users[0].name);
+
+      const second = collapsedChildren.at(1);
+
+      expect(trimText(second.find('.avatar-counter').text())).toBe('+2');
+    });
+
+    it('Shows two reviewers', () => {
+      const users = UsersMockHelper.createNumberRandomUsers(2);
+      createWrapper({
+        ...getDefaultProps(),
+        users,
+        editable: true,
+      });
+
+      expect(wrapper.findAll('.user-item').length).toBe(users.length);
+      expect(wrapper.find('.user-list-more').exists()).toBe(false);
+    });
+
+    it('shows sorted reviewer where "can merge" users are sorted first', () => {
+      const users = UsersMockHelper.createNumberRandomUsers(3);
+      users[0].can_merge = false;
+      users[1].can_merge = false;
+      users[2].can_merge = true;
+
+      createWrapper({
+        ...getDefaultProps(),
+        users,
+        editable: true,
+      });
+
+      expect(wrapper.vm.sortedReviewers[0].can_merge).toBe(true);
+    });
+
+    it('passes the sorted reviewers to the uncollapsed-reviewer-list', () => {
+      const users = UsersMockHelper.createNumberRandomUsers(3);
+      users[0].can_merge = false;
+      users[1].can_merge = false;
+      users[2].can_merge = true;
+
+      createWrapper({
+        ...getDefaultProps(),
+        users,
+      });
+
+      const userItems = wrapper.findAll('.user-list .user-item a');
+
+      expect(userItems.length).toBe(3);
+      expect(userItems.at(0).attributes('title')).toBe(users[2].name);
+    });
+
+    it('passes the sorted reviewers to the collapsed-reviewer-list', () => {
+      const users = UsersMockHelper.createNumberRandomUsers(3);
+      users[0].can_merge = false;
+      users[1].can_merge = false;
+      users[2].can_merge = true;
+
+      createWrapper({
+        ...getDefaultProps(),
+        users,
+      });
+
+      const collapsedButton = wrapper.find('.sidebar-collapsed-user button');
+
+      expect(trimText(collapsedButton.text())).toBe(users[2].name);
+    });
+  });
+});

spec/support/shared_examples/features/editable_merge_request_shared_examples.rb

@@ -11,6 +11,15 @@ RSpec.shared_examples 'an editable merge request' do
       expect(page).to have_content user.name
     end
 
+    find('.js-reviewer-search').click
+    page.within '.dropdown-menu-user' do
+      click_link user.name
+    end
+    expect(find('input[name="merge_request[reviewer_ids][]"]', visible: false).value).to match(user.id.to_s)
+    page.within '.js-reviewer-search' do
+      expect(page).to have_content user.name
+    end
+
     click_button 'Milestone'
     page.within '.issue-milestone' do
       click_link milestone.title
@@ -38,6 +47,10 @@ RSpec.shared_examples 'an editable merge request' do
         expect(page).to have_content user.name
       end
 
+      page.within '.reviewer' do
+        expect(page).to have_content user.name
+      end
+
       page.within '.milestone' do
         expect(page).to have_content milestone.title
       end
@@ -124,16 +137,3 @@ end
 def get_textarea_height
   page.evaluate_script('document.getElementById("merge_request_description").offsetHeight')
 end
-
-RSpec.shared_examples 'an editable merge request with reviewers' do
-  it 'updates merge request', :js do
-    find('.js-reviewer-search').click
-    page.within '.dropdown-menu-user' do
-      click_link user.name
-    end
-    expect(find('input[name="merge_request[reviewer_ids][]"]', visible: false).value).to match(user.id.to_s)
-    page.within '.js-reviewer-search' do
-      expect(page).to have_content user.name
-    end
-  end
-end