Updates on success of an MR the count on top and in other tabs

New API endpoint for merge request count
Updates all open tabs at the same time with one call
Restructured API response

API response changed to 401 if no current_user

Added API + JS specs

Fix for Static Check

Updated Count on Open/Close, Assign/Unassign of MR's

Checking if MR Count is refreshed

Added # frozen_string_literal: true to spec

Added Changelog

15 files changed, 328 insertions, 2 deletions

diff --git a/app/assets/javascripts/api.js b/app/assets/javascripts/api.js
index 4f66a5d080c..a649c521405 100644
--- a/app/assets/javascripts/api.js
+++ b/app/assets/javascripts/api.js
@@ -24,6 +24,7 @@ const Api = {
   issuableTemplatePath: '/:namespace_path/:project_path/templates/:type/:key',
   projectTemplatePath: '/api/:version/projects/:id/templates/:type/:key',
   projectTemplatesPath: '/api/:version/projects/:id/templates/:type',
+  userCountsPath: '/api/:version/user_counts',
   usersPath: '/api/:version/users.json',
   userPath: '/api/:version/users/:id',
   userStatusPath: '/api/:version/users/:id/status',
@@ -312,6 +313,11 @@ const Api = {
     });
   },
 
+  userCounts() {
+    const url = Api.buildUrl(this.userCountsPath);
+    return axios.get(url);
+  },
+
   userStatus(id, options) {
     const url = Api.buildUrl(this.userStatusPath).replace(':id', encodeURIComponent(id));
     return axios.get(url, {
diff --git a/app/assets/javascripts/commons/index.js b/app/assets/javascripts/commons/index.js
index 0d2fe2925d8..ad0f6cc1496 100644
--- a/app/assets/javascripts/commons/index.js
+++ b/app/assets/javascripts/commons/index.js
@@ -4,3 +4,6 @@ import './jquery';
 import './bootstrap';
 import './vue';
 import '../lib/utils/axios_utils';
+import { openUserCountsBroadcast } from './nav/user_merge_requests';
+
+openUserCountsBroadcast();
diff --git a/app/assets/javascripts/commons/nav/user_merge_requests.js b/app/assets/javascripts/commons/nav/user_merge_requests.js
new file mode 100644
index 00000000000..8e694cca6a1
--- /dev/null
+++ b/app/assets/javascripts/commons/nav/user_merge_requests.js
@@ -0,0 +1,67 @@
+import Api from '~/api';
+
+let channel;
+
+function broadcastCount(newCount) {
+  if (!channel) {
+    return;
+  }
+
+  channel.postMessage(newCount);
+}
+
+function updateUserMergeRequestCounts(newCount) {
+  const mergeRequestsCountEl = document.querySelector('.merge-requests-count');
+  mergeRequestsCountEl.textContent = newCount.toLocaleString();
+  mergeRequestsCountEl.classList.toggle('hidden', Number(newCount) === 0);
+}
+
+/**
+ * Refresh user counts (and broadcast if open)
+ */
+export function refreshUserMergeRequestCounts() {
+  return Api.userCounts()
+    .then(({ data }) => {
+      const count = data.merge_requests;
+
+      updateUserMergeRequestCounts(count);
+      broadcastCount(count);
+    })
+    .catch(ex => {
+      console.error(ex); // eslint-disable-line no-console
+    });
+}
+
+/**
+ * Close the broadcast channel for user counts
+ */
+export function closeUserCountsBroadcast() {
+  if (!channel) {
+    return;
+  }
+
+  channel.close();
+  channel = null;
+}
+
+/**
+ * Open the broadcast channel for user counts, adds user id so we only update
+ *
+ * **Please note:**
+ * Not supported in all browsers, but not polyfilling for now
+ * to keep bundle size small and
+ * no special functionality lost except cross tab notifications
+ */
+export function openUserCountsBroadcast() {
+  closeUserCountsBroadcast();
+
+  if (window.BroadcastChannel) {
+    const currentUserId = typeof gon !== 'undefined' && gon && gon.current_user_id;
+    if (currentUserId) {
+      channel = new BroadcastChannel(`mr_count_channel_${currentUserId}`);
+      channel.onmessage = ev => {
+        updateUserMergeRequestCounts(ev.data);
+      };
+    }
+  }
+}
diff --git a/app/assets/javascripts/notes/components/comment_form.vue b/app/assets/javascripts/notes/components/comment_form.vue
index 6c1738f0f1b..fda494fec07 100644
--- a/app/assets/javascripts/notes/components/comment_form.vue
+++ b/app/assets/javascripts/notes/components/comment_form.vue
@@ -13,6 +13,7 @@ import {
   splitCamelCase,
   slugifyWithUnderscore,
 } from '../../lib/utils/text_utility';
+import { refreshUserMergeRequestCounts } from '~/commons/nav/user_merge_requests';
 import * as constants from '../constants';
 import eventHub from '../event_hub';
 import issueWarning from '../../vue_shared/components/issue/issue_warning.vue';
@@ -234,7 +235,10 @@ export default {
     toggleIssueState() {
       if (this.isOpen) {
         this.closeIssue()
-          .then(() => this.enableButton())
+          .then(() => {
+            this.enableButton();
+            refreshUserMergeRequestCounts();
+          })
           .catch(() => {
             this.enableButton();
             this.toggleStateButtonLoading(false);
@@ -247,7 +251,10 @@ export default {
           });
       } else {
         this.reopenIssue()
-          .then(() => this.enableButton())
+          .then(() => {
+            this.enableButton();
+            refreshUserMergeRequestCounts();
+          })
           .catch(({ data }) => {
             this.enableButton();
             this.toggleStateButtonLoading(false);
diff --git a/app/assets/javascripts/sidebar/components/assignees/sidebar_assignees.vue b/app/assets/javascripts/sidebar/components/assignees/sidebar_assignees.vue
index 70dc3d2cdfa..be1e4811856 100644
--- a/app/assets/javascripts/sidebar/components/assignees/sidebar_assignees.vue
+++ b/app/assets/javascripts/sidebar/components/assignees/sidebar_assignees.vue
@@ -2,6 +2,7 @@
 import Flash from '~/flash';
 import eventHub from '~/sidebar/event_hub';
 import Store from '~/sidebar/stores/sidebar_store';
+import { refreshUserMergeRequestCounts } from '~/commons/nav/user_merge_requests';
 import AssigneeTitle from './assignee_title.vue';
 import Assignees from './assignees.vue';
 import { __ } from '~/locale';
@@ -73,6 +74,9 @@ export default {
       this.mediator
         .saveAssignees(this.field)
         .then(setLoadingFalse.bind(this))
+        .then(() => {
+          refreshUserMergeRequestCounts();
+        })
         .catch(() => {
           setLoadingFalse();
           return new Flash(__('Error occurred when saving assignees'));
diff --git a/app/assets/javascripts/vue_merge_request_widget/components/states/ready_to_merge.vue b/app/assets/javascripts/vue_merge_request_widget/components/states/ready_to_merge.vue
index d1f75593d14..d4514767912 100644
--- a/app/assets/javascripts/vue_merge_request_widget/components/states/ready_to_merge.vue
+++ b/app/assets/javascripts/vue_merge_request_widget/components/states/ready_to_merge.vue
@@ -6,6 +6,7 @@ import simplePoll from '~/lib/utils/simple_poll';
 import { __ } from '~/locale';
 import readyToMergeMixin from 'ee_else_ce/vue_merge_request_widget/mixins/ready_to_merge';
 import MergeRequest from '../../../merge_request';
+import { refreshUserMergeRequestCounts } from '~/commons/nav/user_merge_requests';
 import Flash from '../../../flash';
 import statusIcon from '../mr_widget_status_icon.vue';
 import eventHub from '../../event_hub';
@@ -174,6 +175,8 @@ export default {
             MergeRequest.decreaseCounter();
             stopPolling();
 
+            refreshUserMergeRequestCounts();
+
             // If user checked remove source branch and we didn't remove the branch yet
             // we should start another polling for source branch remove process
             if (this.removeSourceBranch && data.source_branch_exists) {
diff --git a/changelogs/unreleased/tz-update-mr-count-over-tabs.yml b/changelogs/unreleased/tz-update-mr-count-over-tabs.yml
new file mode 100644
index 00000000000..61a49dd8ecc
--- /dev/null
+++ b/changelogs/unreleased/tz-update-mr-count-over-tabs.yml
@@ -0,0 +1,6 @@
+---
+title: New API for User Counts, updates on success of an MR the count on top and in
+  other tabs
+merge_request: 29441
+author:
+type: added
diff --git a/doc/api/users.md b/doc/api/users.md
index 884a02dd2bf..213d1865aca 100644
--- a/doc/api/users.md
+++ b/doc/api/users.md
@@ -593,6 +593,30 @@ Example responses
 }
 ```
 
+## User counts
+
+Get the counts (same as in top right menu) of the currently signed in user. 
+
+| Attribute | Type | Description |
+| --------- | ---- | ----------- |
+| `merge_requests`   | number | Merge requests that are active and assigned to current user. |
+
+```
+GET /user_counts
+```
+
+```bash
+curl --header "PRIVATE-TOKEN: <your_access_token>" "https://gitlab.example.com/user_counts"
+```
+
+Example response:
+
+```json
+{
+  "merge_requests": 4
+}
+```
+
 ## List user projects
 
 Please refer to the [List of user projects](projects.md#list-user-projects).
diff --git a/lib/api/api.rb b/lib/api/api.rb
index 42499c5b41e..7016a66593d 100644
--- a/lib/api/api.rb
+++ b/lib/api/api.rb
@@ -166,6 +166,7 @@ module API
     mount ::API::Templates
     mount ::API::Todos
     mount ::API::Triggers
+    mount ::API::UserCounts
     mount ::API::Users
     mount ::API::Variables
     mount ::API::Version
diff --git a/lib/api/user_counts.rb b/lib/api/user_counts.rb
new file mode 100644
index 00000000000..8df4b381bbf
--- /dev/null
+++ b/lib/api/user_counts.rb
@@ -0,0 +1,18 @@
+# frozen_string_literal: true
+
+module API
+  class UserCounts < Grape::API
+    resource :user_counts do
+      desc 'Return the user specific counts' do
+        detail 'Open MR Count'
+      end
+      get do
+        unauthorized! unless current_user
+
+        {
+          merge_requests: current_user.assigned_open_merge_requests_count
+        }
+      end
+    end
+  end
+end
diff --git a/spec/frontend/api_spec.js b/spec/frontend/api_spec.js
index 0188d12a57d..7004373be0e 100644
--- a/spec/frontend/api_spec.js
+++ b/spec/frontend/api_spec.js
@@ -412,6 +412,22 @@ describe('Api', () => {
     });
   });
 
+  describe('user counts', () => {
+    it('fetches single user counts', done => {
+      const expectedUrl = `${dummyUrlRoot}/api/${dummyApiVersion}/user_counts`;
+      mock.onGet(expectedUrl).reply(200, {
+        merge_requests: 4,
+      });
+
+      Api.userCounts()
+        .then(({ data }) => {
+          expect(data.merge_requests).toBe(4);
+        })
+        .then(done)
+        .catch(done.fail);
+    });
+  });
+
   describe('user status', () => {
     it('fetches single user status', done => {
       const userId = '123456';
diff --git a/spec/frontend/commons/nav/user_merge_requests_spec.js b/spec/frontend/commons/nav/user_merge_requests_spec.js
new file mode 100644
index 00000000000..4da6d53557a
--- /dev/null
+++ b/spec/frontend/commons/nav/user_merge_requests_spec.js
@@ -0,0 +1,113 @@
+import {
+  openUserCountsBroadcast,
+  closeUserCountsBroadcast,
+  refreshUserMergeRequestCounts,
+} from '~/commons/nav/user_merge_requests';
+import Api from '~/api';
+
+jest.mock('~/api');
+
+const TEST_COUNT = 1000;
+const MR_COUNT_CLASS = 'merge-requests-count';
+
+describe('User Merge Requests', () => {
+  let channelMock;
+  let newBroadcastChannelMock;
+
+  beforeEach(() => {
+    global.gon.current_user_id = 123;
+
+    channelMock = {
+      postMessage: jest.fn(),
+      close: jest.fn(),
+    };
+    newBroadcastChannelMock = jest.fn().mockImplementation(() => channelMock);
+
+    global.BroadcastChannel = newBroadcastChannelMock;
+    setFixtures(`<div class="${MR_COUNT_CLASS}">0</div>`);
+  });
+
+  const findMRCountText = () => document.body.querySelector(`.${MR_COUNT_CLASS}`).textContent;
+
+  describe('refreshUserMergeRequestCounts', () => {
+    beforeEach(() => {
+      Api.userCounts.mockReturnValue(
+        Promise.resolve({
+          data: { merge_requests: TEST_COUNT },
+        }),
+      );
+    });
+
+    describe('with open broadcast channel', () => {
+      beforeEach(() => {
+        openUserCountsBroadcast();
+
+        return refreshUserMergeRequestCounts();
+      });
+
+      it('updates the top count of merge requests', () => {
+        expect(findMRCountText()).toEqual(TEST_COUNT.toLocaleString());
+      });
+
+      it('calls the API', () => {
+        expect(Api.userCounts).toHaveBeenCalled();
+      });
+
+      it('posts count to BroadcastChannel', () => {
+        expect(channelMock.postMessage).toHaveBeenCalledWith(TEST_COUNT);
+      });
+    });
+
+    describe('without open broadcast channel', () => {
+      beforeEach(() => refreshUserMergeRequestCounts());
+
+      it('does not post anything', () => {
+        expect(channelMock.postMessage).not.toHaveBeenCalled();
+      });
+    });
+  });
+
+  describe('openUserCountsBroadcast', () => {
+    beforeEach(() => {
+      openUserCountsBroadcast();
+    });
+
+    it('creates BroadcastChannel that updates DOM on message received', () => {
+      expect(findMRCountText()).toEqual('0');
+
+      channelMock.onmessage({ data: TEST_COUNT });
+
+      expect(findMRCountText()).toEqual(TEST_COUNT.toLocaleString());
+    });
+
+    it('closes if called while already open', () => {
+      expect(channelMock.close).not.toHaveBeenCalled();
+
+      openUserCountsBroadcast();
+
+      expect(channelMock.close).toHaveBeenCalled();
+    });
+  });
+
+  describe('closeUserCountsBroadcast', () => {
+    describe('when not opened', () => {
+      it('does nothing', () => {
+        expect(channelMock.close).not.toHaveBeenCalled();
+      });
+    });
+
+    describe('when opened', () => {
+      beforeEach(() => {
+        openUserCountsBroadcast();
+      });
+
+      it('closes', () => {
+        expect(channelMock.close).not.toHaveBeenCalled();
+
+        closeUserCountsBroadcast();
+
+        expect(channelMock.close).toHaveBeenCalled();
+      });
+    });
+  });
+});
diff --git a/spec/javascripts/notes/components/comment_form_spec.js b/spec/javascripts/notes/components/comment_form_spec.js
index 362963ddaf4..88c86746992 100644
--- a/spec/javascripts/notes/components/comment_form_spec.js
+++ b/spec/javascripts/notes/components/comment_form_spec.js
@@ -251,6 +251,21 @@ describe('issue_comment_form component', () => {
           });
         });
       });
+
+      describe('when toggling state', () => {
+        it('should update MR count', done => {
+          spyOn(vm, 'closeIssue').and.returnValue(Promise.resolve());
+
+          const updateMrCountSpy = spyOnDependency(CommentForm, 'refreshUserMergeRequestCounts');
+          vm.toggleIssueState();
+
+          Vue.nextTick(() => {
+            expect(updateMrCountSpy).toHaveBeenCalled();
+
+            done();
+          });
+        });
+      });
     });
 
     describe('issue is confidential', () => {
diff --git a/spec/javascripts/vue_mr_widget/components/states/mr_widget_ready_to_merge_spec.js b/spec/javascripts/vue_mr_widget/components/states/mr_widget_ready_to_merge_spec.js
index bb76616be56..ba3ba01944d 100644
--- a/spec/javascripts/vue_mr_widget/components/states/mr_widget_ready_to_merge_spec.js
+++ b/spec/javascripts/vue_mr_widget/components/states/mr_widget_ready_to_merge_spec.js
@@ -58,9 +58,11 @@ const createComponent = (customConfig = {}) => {
 
 describe('ReadyToMerge', () => {
   let vm;
+  let updateMrCountSpy;
 
   beforeEach(() => {
     vm = createComponent();
+    updateMrCountSpy = spyOnDependency(ReadyToMerge, 'refreshUserMergeRequestCounts');
   });
 
   afterEach(() => {
@@ -461,6 +463,7 @@ describe('ReadyToMerge', () => {
           expect(eventHub.$emit).toHaveBeenCalledWith('MRWidgetUpdateRequested');
           expect(eventHub.$emit).toHaveBeenCalledWith('FetchActionsContent');
           expect(vm.initiateRemoveSourceBranchPolling).toHaveBeenCalled();
+          expect(updateMrCountSpy).toHaveBeenCalled();
           expect(cpc).toBeFalsy();
           expect(spc).toBeTruthy();
 
diff --git a/spec/requests/api/user_counts_spec.rb b/spec/requests/api/user_counts_spec.rb
new file mode 100644
index 00000000000..c833bd047e2
--- /dev/null
+++ b/spec/requests/api/user_counts_spec.rb
@@ -0,0 +1,40 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe API::UserCounts do
+  let(:user) { create(:user) }
+  let(:project) { create(:project, :public) }
+
+  let!(:merge_request) { create(:merge_request, :simple, author: user, assignees: [user], source_project: project, title: "Test") }
+
+  describe 'GET /user_counts' do
+    context 'when unauthenticated' do
+      it 'returns authentication error' do
+        get api('/user_counts')
+
+        expect(response.status).to eq(401)
+      end
+    end
+
+    context 'when authenticated' do
+      it 'returns open counts for current user' do
+        get api('/user_counts', user)
+
+        expect(response.status).to eq(200)
+        expect(json_response).to be_a Hash
+        expect(json_response['merge_requests']).to eq(1)
+      end
+
+      it 'updates the mr count when a new mr is assigned' do
+        create(:merge_request, source_project: project, author: user, assignees: [user])
+
+        get api('/user_counts', user)
+
+        expect(response.status).to eq(200)
+        expect(json_response).to be_a Hash
+        expect(json_response['merge_requests']).to eq(2)
+      end
+    end
+  end
+end