Added labels real-time update

Added the backend implementation of labels-updating subscription and used it on the frontend.

Fixed assignees real-time updates not working on issue boards

Broadcast labels on issuable update

app/assets/javascripts/sidebar/components/assignees/assignees_realtime.vue

 <script>
-import produce from 'immer';
-import { convertToGraphQLId, getIdFromGraphQLId } from '~/graphql_shared/utils';
+import { getIdFromGraphQLId } from '~/graphql_shared/utils';
 import { IssuableType } from '~/issues/constants';
 import { assigneesQueries } from '~/sidebar/constants';
 
@@ -17,10 +16,6 @@ export default {
       type: String,
       required: true,
     },
-    issuableId: {
-      type: Number,
-      required: true,
-    },
     queryVariables: {
       type: Object,
       required: true,
@@ -30,6 +25,9 @@ export default {
     issuableClass() {
       return Object.keys(IssuableType).find((key) => IssuableType[key] === this.issuableType);
     },
+    issuableId() {
+      return this.issuable?.id;
+    },
   },
   apollo: {
     issuable: {
@@ -48,29 +46,36 @@ export default {
         },
         variables() {
           return {
-            issuableId: convertToGraphQLId(this.issuableClass, this.issuableId),
+            issuableId: this.issuableId,
           };
         },
-        updateQuery(prev, { subscriptionData }) {
-          if (prev && subscriptionData?.data?.issuableAssigneesUpdated) {
-            const data = produce(prev, (draftData) => {
-              draftData.workspace.issuable.assignees.nodes =
-                subscriptionData.data.issuableAssigneesUpdated.assignees.nodes;
-            });
+        skip() {
+          return !this.issuableId;
+        },
+        updateQuery(
+          _,
+          {
+            subscriptionData: {
+              data: { issuableAssigneesUpdated },
+            },
+          },
+        ) {
+          if (issuableAssigneesUpdated) {
+            const {
+              id,
+              assignees: { nodes },
+            } = issuableAssigneesUpdated;
             if (this.mediator) {
-              this.handleFetchResult(data);
+              this.handleFetchResult(nodes);
             }
-            return data;
+            this.$emit('assigneesUpdated', { id, assignees: nodes });
           }
-          return prev;
         },
       },
     },
   },
   methods: {
-    handleFetchResult(data) {
-      const { nodes } = data.workspace.issuable.assignees;
-
+    handleFetchResult(nodes) {
       const assignees = nodes.map((n) => ({
         ...n,
         avatar_url: n.avatarUrl,

app/assets/javascripts/sidebar/components/assignees/sidebar_assignees_widget.vue

@@ -232,6 +232,7 @@ export default {
       :issuable-type="issuableType"
       :issuable-id="issuableId"
       :query-variables="queryVariables"
+      @assigneesUpdated="$emit('assignees-updated', $event)"
     />
     <sidebar-editable-item
       ref="toggle"

app/assets/javascripts/sidebar/queries/issuable_labels.subscription.graphql

+#import "~/graphql_shared/fragments/label.fragment.graphql"
+
+subscription issuableLabelsUpdated($issuableId: IssuableID!) {
+  issuableLabelsUpdated(issuableId: $issuableId) {
+    ... on Issue {
+      id
+      labels {
+        nodes {
+          ...Label
+        }
+      }
+    }
+    ... on MergeRequest {
+      id
+      labels {
+        nodes {
+          ...Label
+        }
+      }
+    }
+  }
+}

app/assets/javascripts/vue_shared/components/sidebar/labels_select_widget/labels_select_root.vue

 <script>
 import { debounce } from 'lodash';
+import issuableLabelsSubscription from 'ee_else_ce/sidebar/queries/issuable_labels.subscription.graphql';
 import { MutationOperationMode, getIdFromGraphQLId } from '~/graphql_shared/utils';
 import createFlash from '~/flash';
+import glFeatureFlagsMixin from '~/vue_shared/mixins/gl_feature_flags_mixin';
 import { IssuableType } from '~/issues/constants';
+
 import { __ } from '~/locale';
 import SidebarEditableItem from '~/sidebar/components/sidebar_editable_item.vue';
 import { issuableLabelsQueries } from '~/sidebar/constants';
@@ -21,6 +24,7 @@ export default {
     DropdownContents,
     SidebarEditableItem,
   },
+  mixins: [glFeatureFlagsMixin()],
   inject: {
     allowLabelEdit: {
       default: false,
@@ -106,7 +110,7 @@ export default {
   data() {
     return {
       contentIsOnViewport: true,
-      issuableLabels: [],
+      issuable: null,
       labelsSelectInProgress: false,
       oldIid: null,
       sidebarExpandedOnClick: false,
@@ -114,14 +118,23 @@ export default {
   },
   computed: {
     isLoading() {
-      return this.labelsSelectInProgress || this.$apollo.queries.issuableLabels.loading;
+      return this.labelsSelectInProgress || this.$apollo.queries.issuable.loading;
     },
     issuableLabelIds() {
       return this.issuableLabels.map((label) => label.id);
     },
+    issuableLabels() {
+      return this.issuable?.labels.nodes || [];
+    },
+    issuableId() {
+      return this.issuable?.id;
+    },
+    isRealtimeEnabled() {
+      return this.glFeatures.realtimeLabels;
+    },
   },
   apollo: {
-    issuableLabels: {
+    issuable: {
       query() {
         return issuableLabelsQueries[this.issuableType].issuableQuery;
       },
@@ -135,11 +148,40 @@ export default {
         };
       },
       update(data) {
-        return data.workspace?.issuable?.labels.nodes || [];
+        return data.workspace?.issuable;
       },
       error() {
         createFlash({ message: __('Error fetching labels.') });
       },
+      subscribeToMore: {
+        document() {
+          return issuableLabelsSubscription;
+        },
+        variables() {
+          return {
+            issuableId: this.issuableId,
+          };
+        },
+        skip() {
+          return !this.issuableId || !this.isDropdownVariantSidebar || !this.isRealtimeEnabled;
+        },
+        updateQuery(
+          _,
+          {
+            subscriptionData: {
+              data: { issuableLabelsUpdated },
+            },
+          },
+        ) {
+          if (issuableLabelsUpdated) {
+            const {
+              id,
+              labels: { nodes },
+            } = issuableLabelsUpdated;
+            this.$emit('updateSelectedLabels', { id, labels: nodes });
+          }
+        },
+      },
     },
   },
   watch: {

app/controllers/groups/boards_controller.rb

@@ -9,6 +9,7 @@ class Groups::BoardsController < Groups::ApplicationController
   before_action do
     push_frontend_feature_flag(:board_multi_select, group, default_enabled: :yaml)
     push_frontend_feature_flag(:iteration_cadences, group, default_enabled: :yaml)
+    push_frontend_feature_flag(:realtime_labels, group, default_enabled: :yaml)
     experiment(:prominent_create_board_btn, subject: current_user) do |e|
       e.control { }
       e.candidate { }

app/controllers/projects/boards_controller.rb

@@ -9,6 +9,7 @@ class Projects::BoardsController < Projects::ApplicationController
   before_action do
     push_frontend_feature_flag(:board_multi_select, project, default_enabled: :yaml)
     push_frontend_feature_flag(:iteration_cadences, project&.group, default_enabled: :yaml)
+    push_frontend_feature_flag(:realtime_labels, project&.group, default_enabled: :yaml)
     experiment(:prominent_create_board_btn, subject: current_user) do |e|
       e.control { }
       e.candidate { }

app/controllers/projects/issues_controller.rb

@@ -49,6 +49,7 @@ class Projects::IssuesController < Projects::ApplicationController
     push_frontend_feature_flag(:confidential_notes, project&.group, default_enabled: :yaml)
     push_frontend_feature_flag(:issue_assignees_widget, project, default_enabled: :yaml)
     push_frontend_feature_flag(:paginated_issue_discussions, project, default_enabled: :yaml)
+    push_frontend_feature_flag(:realtime_labels, project, default_enabled: :yaml)
     push_force_frontend_feature_flag(:work_items, project&.work_items_feature_flag_enabled?)
   end
 

app/controllers/projects/merge_requests_controller.rb

@@ -43,6 +43,7 @@ class Projects::MergeRequestsController < Projects::MergeRequests::ApplicationCo
     push_frontend_feature_flag(:markdown_continue_lists, project, default_enabled: :yaml)
     push_frontend_feature_flag(:secure_vulnerability_training, project, default_enabled: :yaml)
     push_frontend_feature_flag(:issue_assignees_widget, @project, default_enabled: :yaml)
+    push_frontend_feature_flag(:realtime_labels, project, default_enabled: :yaml)
     # Usage data feature flags
     push_frontend_feature_flag(:users_expanding_widgets_usage_data, project, default_enabled: :yaml)
     push_frontend_feature_flag(:diff_settings_usage_data, default_enabled: :yaml)

app/graphql/graphql_triggers.rb

@@ -12,4 +12,8 @@ module GraphqlTriggers
   def self.issuable_title_updated(issuable)
     GitlabSchema.subscriptions.trigger('issuableTitleUpdated', { issuable_id: issuable.to_gid }, issuable)
   end
+
+  def self.issuable_labels_updated(issuable)
+    GitlabSchema.subscriptions.trigger('issuableLabelsUpdated', { issuable_id: issuable.to_gid }, issuable)
+  end
 end

app/graphql/types/subscription_type.rb

@@ -12,5 +12,8 @@ module Types
 
     field :issuable_title_updated, subscription: Subscriptions::IssuableUpdated, null: true,
           description: 'Triggered when the title of an issuable is updated.'
+
+    field :issuable_labels_updated, subscription: Subscriptions::IssuableUpdated, null: true,
+          description: 'Triggered when the labels of an issuable are updated.'
   end
 end

app/services/issuable_base_service.rb

@@ -525,12 +525,23 @@ class IssuableBaseService < ::BaseProjectService
     attrs_changed || labels_changed || assignees_changed || reviewers_changed
   end
 
+  def has_label_changes?(issuable, old_labels)
+    Set.new(issuable.labels) != Set.new(old_labels)
+  end
+
   def invalidate_cache_counts(issuable, users: [])
     users.each do |user|
       user.public_send("invalidate_#{issuable.noteable_target_type_name}_cache_counts") # rubocop:disable GitlabSecurity/PublicSend
     end
   end
 
+  # override if needed
+  def handle_label_changes(issuable, old_labels)
+    return unless has_label_changes?(issuable, old_labels)
+
+    GraphqlTriggers.issuable_labels_updated(issuable)
+  end
+
   # override if needed
   def handle_changes(issuable, options)
   end

app/services/issues/update_service.rb

@@ -63,6 +63,7 @@ module Issues
 
       handle_assignee_changes(issue, old_assignees)
       handle_confidential_change(issue)
+      handle_label_changes(issue, old_labels)
       handle_added_labels(issue, old_labels)
       handle_milestone_change(issue)
       handle_added_mentions(issue, old_mentioned_users)

app/services/merge_requests/update_service.rb

@@ -34,6 +34,7 @@ module MergeRequests
       handle_target_branch_change(merge_request)
       handle_milestone_change(merge_request)
       handle_draft_status_change(merge_request, changed_fields)
+      handle_label_changes(merge_request, old_labels)
 
       track_title_and_desc_edits(changed_fields)
       track_discussion_lock_toggle(merge_request, changed_fields)

config/feature_flags/development/realtime_labels.yml

+---
+name: realtime_labels
+introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/83743
+rollout_issue_url: https://gitlab.com/gitlab-org/gitlab/-/issues/357370
+milestone: '14.10'
+type: development
+group: group::project management
+default_enabled: false

ee/app/assets/javascripts/sidebar/queries/issuable_labels.subscription.graphql

+#import "~/graphql_shared/fragments/label.fragment.graphql"
+
+subscription issuableLabelsUpdatedEE($issuableId: IssuableID!) {
+  issuableLabelsUpdated(issuableId: $issuableId) {
+    ... on Issue {
+      id
+      labels {
+        nodes {
+          ...Label
+        }
+      }
+    }
+    ... on MergeRequest {
+      id
+      labels {
+        nodes {
+          ...Label
+        }
+      }
+    }
+    ... on Epic {
+      id
+      labels {
+        nodes {
+          ...Label
+        }
+      }
+    }
+  }
+}

ee/app/controllers/groups/epic_boards_controller.rb

@@ -9,6 +9,10 @@ class Groups::EpicBoardsController < Groups::ApplicationController
   before_action :redirect_to_recent_board, only: [:index]
   before_action :assign_endpoint_vars
 
+  before_action do
+    push_frontend_feature_flag(:realtime_labels, group, default_enabled: :yaml)
+  end
+
   track_redis_hll_event :index, :show, name: 'g_project_management_users_viewing_epic_boards'
 
   feature_category :portfolio_management

ee/app/controllers/groups/epics_controller.rb

@@ -19,6 +19,7 @@ class Groups::EpicsController < Groups::ApplicationController
   before_action do
     push_frontend_feature_flag(:related_epics_widget, @group, type: :development, default_enabled: :yaml)
     push_frontend_feature_flag(:confidential_notes, @group, type: :development, default_enabled: :yaml)
+    push_frontend_feature_flag(:realtime_labels, group, default_enabled: :yaml)
   end
 
   feature_category :portfolio_management

ee/app/services/epics/update_service.rb

@@ -45,9 +45,7 @@ module Epics
       old_mentioned_users = old_associations.fetch(:mentioned_users, [])
       old_labels = old_associations.fetch(:labels, [])
 
-      if has_changes?(epic, old_labels: old_labels)
-        todo_service.resolve_todos_for_target(epic, current_user)
-      end
+      handle_label_changes(epic, old_labels)
 
       todo_service.update_epic(epic, current_user, old_mentioned_users)
 
@@ -56,6 +54,14 @@ module Epics
       end
     end
 
+    def handle_label_changes(epic, old_labels)
+      return unless has_label_changes?(epic, old_labels)
+
+      super
+
+      todo_service.resolve_todos_for_target(epic, current_user)
+    end
+
     def handle_confidentiality_change(epic)
       if epic.confidential?
         ::Gitlab::UsageDataCounters::EpicActivityUniqueCounter.track_epic_confidential_action(author: current_user)

ee/spec/services/epics/update_service_spec.rb

@@ -537,6 +537,16 @@ RSpec.describe Epics::UpdateService do
       let(:parent) { group }
     end
 
+    it_behaves_like 'broadcasting issuable labels updates' do
+      let(:label_a) { create(:group_label, group: group) }
+      let(:label_b) { create(:group_label, group: group) }
+      let(:issuable) { epic }
+
+      def update_issuable(update_params)
+        update_epic(update_params)
+      end
+    end
+
     context 'with quick actions in the description' do
       before do
         stub_licensed_features(epics: true, subepics: true)

spec/features/issues/user_sees_sidebar_updates_in_realtime_spec.rb

@@ -6,6 +6,10 @@ RSpec.describe 'Issues > Real-time sidebar', :js do
   let_it_be(:project) { create(:project, :public) }
   let_it_be(:issue) { create(:issue, project: project) }
   let_it_be(:user) { create(:user) }
+  let_it_be(:label)  { create(:label, project: project, name: 'Development') }
+
+  let(:labels_widget) { find('[data-testid="sidebar-labels"]') }
+  let(:labels_value) { find('[data-testid="value-wrapper"]') }
 
   before_all do
     project.add_developer(user)
@@ -32,4 +36,37 @@ RSpec.describe 'Issues > Real-time sidebar', :js do
       expect(page.find('.assignee')).to have_content user.name
     end
   end
+
+  it 'updates the label in real-time' do
+    Capybara::Session.new(:other_session)
+
+    using_session :other_session do
+      visit project_issue_path(project, issue)
+      wait_for_requests
+      expect(labels_value).to have_content('None')
+    end
+
+    sign_in(user)
+
+    visit project_issue_path(project, issue)
+    wait_for_requests
+    expect(labels_value).to have_content('None')
+
+    page.within(labels_widget) do
+      click_on 'Edit'
+    end
+
+    wait_for_all_requests
+
+    click_button label.name
+    click_button 'Close'
+
+    wait_for_requests
+
+    expect(labels_value).to have_content(label.name)
+
+    using_session :other_session do
+      expect(labels_value).to have_content(label.name)
+    end
+  end
 end

spec/frontend/sidebar/assignees_realtime_spec.js

@@ -2,11 +2,16 @@ import { shallowMount } from '@vue/test-utils';
 import Vue from 'vue';
 import VueApollo from 'vue-apollo';
 import createMockApollo from 'helpers/mock_apollo_helper';
+import waitForPromises from 'helpers/wait_for_promises';
 import AssigneesRealtime from '~/sidebar/components/assignees/assignees_realtime.vue';
 import issuableAssigneesSubscription from '~/sidebar/queries/issuable_assignees.subscription.graphql';
 import SidebarMediator from '~/sidebar/sidebar_mediator';
 import getIssueAssigneesQuery from '~/vue_shared/components/sidebar/queries/get_issue_assignees.query.graphql';
-import Mock, { issuableQueryResponse, subscriptionNullResponse } from './mock_data';
+import Mock, {
+  issuableQueryResponse,
+  subscriptionNullResponse,
+  subscriptionResponse,
+} from './mock_data';
 
 Vue.use(VueApollo);
 
@@ -20,7 +25,6 @@ describe('Assignees Realtime', () => {
 
   const createComponent = ({
     issuableType = 'issue',
-    issuableId = 1,
     subscriptionHandler = subscriptionInitialHandler,
   } = {}) => {
     fakeApollo = createMockApollo([
@@ -30,7 +34,6 @@ describe('Assignees Realtime', () => {
     wrapper = shallowMount(AssigneesRealtime, {
       propsData: {
         issuableType,
-        issuableId,
         queryVariables: {
           issuableIid: '1',
           projectPath: 'path/to/project',
@@ -60,11 +63,23 @@ describe('Assignees Realtime', () => {
     });
   });
 
-  it('calls the subscription with correct variable for issue', () => {
+  it('calls the subscription with correct variable for issue', async () => {
     createComponent();
+    await waitForPromises();
 
     expect(subscriptionInitialHandler).toHaveBeenCalledWith({
       issuableId: 'gid://gitlab/Issue/1',
     });
   });
+
+  it('emits an `assigneesUpdated` event on subscription response', async () => {
+    createComponent({
+      subscriptionHandler: jest.fn().mockResolvedValue(subscriptionResponse),
+    });
+    await waitForPromises();
+
+    expect(wrapper.emitted('assigneesUpdated')).toEqual([
+      [{ id: '1', assignees: subscriptionResponse.data.issuableAssigneesUpdated.assignees.nodes }],
+    ]);
+  });
 });

spec/frontend/sidebar/mock_data.js

@@ -415,6 +415,28 @@ export const subscriptionNullResponse = {
   },
 };
 
+export const subscriptionResponse = {
+  data: {
+    issuableAssigneesUpdated: {
+      id: '1',
+      assignees: {
+        nodes: [
+          {
+            __typename: 'UserCore',
+            id: 'gid://gitlab/User/1',
+            avatarUrl:
+              'https://www.gravatar.com/avatar/e64c7d89f26bd1972efa854d13d7dd61?s=80\u0026d=identicon',
+            name: 'Administrator',
+            username: 'root',
+            webUrl: '/root',
+            status: null,
+          },
+        ],
+      },
+    },
+  },
+};
+
 const mockUser1 = {
   __typename: 'UserCore',
   id: 'gid://gitlab/User/1',

spec/frontend/vue_shared/components/sidebar/labels_select_widget/labels_select_root_spec.js

@@ -11,9 +11,15 @@ import DropdownValue from '~/vue_shared/components/sidebar/labels_select_widget/
 import issueLabelsQuery from '~/vue_shared/components/sidebar/labels_select_widget/graphql/issue_labels.query.graphql';
 import updateIssueLabelsMutation from '~/boards/graphql/issue_set_labels.mutation.graphql';
 import updateMergeRequestLabelsMutation from '~/sidebar/queries/update_merge_request_labels.mutation.graphql';
+import issuableLabelsSubscription from 'ee_else_ce/sidebar/queries/issuable_labels.subscription.graphql';
 import updateEpicLabelsMutation from '~/vue_shared/components/sidebar/labels_select_widget/graphql/epic_update_labels.mutation.graphql';
 import LabelsSelectRoot from '~/vue_shared/components/sidebar/labels_select_widget/labels_select_root.vue';
-import { mockConfig, issuableLabelsQueryResponse, updateLabelsMutationResponse } from './mock_data';
+import {
+  mockConfig,
+  issuableLabelsQueryResponse,
+  updateLabelsMutationResponse,
+  issuableLabelsSubscriptionResponse,
+} from './mock_data';
 
 jest.mock('~/flash');
 
@@ -21,6 +27,7 @@ Vue.use(VueApollo);
 
 const successfulQueryHandler = jest.fn().mockResolvedValue(issuableLabelsQueryResponse);
 const successfulMutationHandler = jest.fn().mockResolvedValue(updateLabelsMutationResponse);
+const subscriptionHandler = jest.fn().mockResolvedValue(issuableLabelsSubscriptionResponse);
 const errorQueryHandler = jest.fn().mockRejectedValue('Houston, we have a problem');
 
 const updateLabelsMutation = {
@@ -42,10 +49,12 @@ describe('LabelsSelectRoot', () => {
     issuableType = IssuableType.Issue,
     queryHandler = successfulQueryHandler,
     mutationHandler = successfulMutationHandler,
+    isRealtimeEnabled = false,
   } = {}) => {
     const mockApollo = createMockApollo([
       [issueLabelsQuery, queryHandler],
       [updateLabelsMutation[issuableType], mutationHandler],
+      [issuableLabelsSubscription, subscriptionHandler],
     ]);
 
     wrapper = shallowMount(LabelsSelectRoot, {
@@ -65,6 +74,9 @@ describe('LabelsSelectRoot', () => {
         allowLabelEdit: true,
         allowLabelCreate: true,
         labelsManagePath: 'test',
+        glFeatures: {
+          realtimeLabels: isRealtimeEnabled,
+        },
       },
     });
   };
@@ -190,5 +202,26 @@ describe('LabelsSelectRoot', () => {
         message: 'An error occurred while updating labels.',
       });
     });
+
+    it('does not emit `updateSelectedLabels` event when the subscription is triggered and FF is disabled', async () => {
+      createComponent();
+      await waitForPromises();
+
+      expect(wrapper.emitted('updateSelectedLabels')).toBeUndefined();
+    });
+
+    it('emits `updateSelectedLabels` event when the subscription is triggered and FF is enabled', async () => {
+      createComponent({ isRealtimeEnabled: true });
+      await waitForPromises();
+
+      expect(wrapper.emitted('updateSelectedLabels')).toEqual([
+        [
+          {
+            id: '1',
+            labels: issuableLabelsSubscriptionResponse.data.issuableLabelsUpdated.labels.nodes,
+          },
+        ],
+      ]);
+    });
   });
 });

spec/frontend/vue_shared/components/sidebar/labels_select_widget/mock_data.js

@@ -141,6 +141,34 @@ export const issuableLabelsQueryResponse = {
   },
 };
 
+export const issuableLabelsSubscriptionResponse = {
+  data: {
+    issuableLabelsUpdated: {
+      id: '1',
+      labels: {
+        nodes: [
+          {
+            __typename: 'Label',
+            color: '#330066',
+            description: null,
+            id: 'gid://gitlab/ProjectLabel/1',
+            title: 'Label1',
+            textColor: '#000000',
+          },
+          {
+            __typename: 'Label',
+            color: '#000000',
+            description: null,
+            id: 'gid://gitlab/ProjectLabel/2',
+            title: 'Label2',
+            textColor: '#ffffff',
+          },
+        ],
+      },
+    },
+  },
+};
+
 export const updateLabelsMutationResponse = {
   data: {
     updateIssuableLabels: {

spec/graphql/graphql_triggers_spec.rb

@@ -31,4 +31,20 @@ RSpec.describe GraphqlTriggers do
       GraphqlTriggers.issuable_title_updated(work_item)
     end
   end
+
+  describe '.issuable_labels_updated' do
+    it 'triggers the issuableLabelsUpdated subscription' do
+      project = create(:project)
+      labels = create_list(:label, 3, project: project)
+      issue = create(:issue, labels: labels)
+
+      expect(GitlabSchema.subscriptions).to receive(:trigger).with(
+        'issuableLabelsUpdated',
+        { issuable_id: issue.to_gid },
+        issue
+      )
+
+      GraphqlTriggers.issuable_labels_updated(issue)
+    end
+  end
 end

spec/graphql/types/subscription_type_spec.rb

@@ -8,6 +8,7 @@ RSpec.describe GitlabSchema.types['Subscription'] do
       issuable_assignees_updated
       issue_crm_contacts_updated
       issuable_title_updated
+      issuable_labels_updated
     ]
 
     expect(described_class).to have_graphql_fields(*expected_fields).only

spec/services/issues/update_service_spec.rb

@@ -1361,6 +1361,16 @@ RSpec.describe Issues::UpdateService, :mailer do
       end
     end
 
+    it_behaves_like 'broadcasting issuable labels updates' do
+      let(:label_a) { label }
+      let(:label_b) { label2 }
+      let(:issuable) { issue }
+
+      def update_issuable(update_params)
+        update_issue(update_params)
+      end
+    end
+
     it_behaves_like 'issuable record that supports quick actions' do
       let(:existing_issue) { create(:issue, project: project) }
       let(:issuable) { described_class.new(project: project, current_user: user, params: params).execute(existing_issue) }

spec/services/merge_requests/update_service_spec.rb

@@ -1192,5 +1192,15 @@ RSpec.describe MergeRequests::UpdateService, :mailer do
       let(:existing_merge_request) { create(:merge_request, source_project: project) }
       let(:issuable) { described_class.new(project: project, current_user: user, params: params).execute(existing_merge_request) }
     end
+
+    it_behaves_like 'broadcasting issuable labels updates' do
+      let(:label_a) { label }
+      let(:label_b) { create(:label, project: project) }
+      let(:issuable) { merge_request }
+
+      def update_issuable(update_params)
+        update_merge_request(update_params)
+      end
+    end
   end
 end

spec/support/services/issuable_update_service_shared_examples.rb

@@ -23,3 +23,33 @@ RSpec.shared_examples 'issuable update service' do
     end
   end
 end
+
+RSpec.shared_examples 'broadcasting issuable labels updates' do
+  before do
+    update_issuable(label_ids: [label_a.id])
+  end
+
+  context 'when label is added' do
+    it 'triggers the GraphQL subscription' do
+      expect(GraphqlTriggers).to receive(:issuable_labels_updated).with(issuable)
+
+      update_issuable({ add_label_ids: [label_b.id] })
+    end
+  end
+
+  context 'when label is removed' do
+    it 'triggers the GraphQL subscription' do
+      expect(GraphqlTriggers).to receive(:issuable_labels_updated).with(issuable)
+
+      update_issuable({ remove_label_ids: [label_a.id] })
+    end
+  end
+
+  context 'when label is unchanged' do
+    it 'does not trigger the GraphQL subscription' do
+      expect(GraphqlTriggers).not_to receive(:issuable_labels_updated).with(issuable)
+
+      update_issuable({ label_ids: [label_a.id] })
+    end
+  end
+end