queueMarkAsRead, test: Check messageFlags is not called in less than 2s.

src/__tests__/exampleData.js

@@ -4,9 +4,10 @@ import { createStore } from 'redux';
 
 import type { CrossRealmBot, Message, PmRecipientUser, Stream, User } from '../api/modelTypes';
 import type { GlobalState, RealmState } from '../reduxTypes';
-import type { Account } from '../types';
+import type { Auth, Account } from '../types';
 import { ACCOUNT_SWITCH, LOGIN_SUCCESS } from '../actionConstants';
 import rootReducer from '../boot/reducers';
+import { authOfAccount } from '../account/accountMisc';
 
 // TODO either fix Jest test-discovery patterns, or rename this file,
 // so this dummy test isn't required.
@@ -66,6 +67,7 @@ const makeAccount = (user: User): Account => ({
 
 const selfUser: User = makeUser({ name: 'self' });
 const selfAccount: Account = makeAccount(selfUser);
+const selfAuth: Auth = authOfAccount(selfAccount);
 
 const otherUser: User = makeUser({ name: 'other' });
 
@@ -221,6 +223,7 @@ export const eg = {
   makeCrossRealmBot,
   selfUser,
   selfAccount,
+  selfAuth,
   otherUser,
   crossRealmBot,
   makeStream,

src/api/__tests__/queueMarkAsRead-test.js

@@ -0,0 +1,40 @@
+/* @flow strict-local */
+import queueMarkAsRead, { resetAll } from '../queueMarkAsRead';
+import * as messagesFlags from '../messages/messagesFlags';
+import { eg } from '../../__tests__/exampleData';
+
+// $FlowFixMe Make flow understand about mocking
+messagesFlags.default = jest.fn(() => {});
+
+describe('queueMarkAsRead', () => {
+  beforeEach(() => {
+    resetAll();
+    jest.clearAllMocks();
+    jest.clearAllTimers();
+  });
+
+  test('should not call messagesFlags on consecutive calls of queueMarkAsRead', () => {
+    queueMarkAsRead(eg.selfAuth, [1, 2, 3]);
+    queueMarkAsRead(eg.selfAuth, [4, 5, 6]);
+    queueMarkAsRead(eg.selfAuth, [7, 8, 9]);
+    queueMarkAsRead(eg.selfAuth, [10, 11, 12]);
+
+    expect(messagesFlags.default).toHaveBeenCalledTimes(1);
+  });
+
+  test('should call messagesFlags, if calls to queueMarkAsRead are 2s apart', async () => {
+    const currentDate = Date.now();
+    const secondCall = currentDate + 2100;
+    // $FlowFixMe Make flow understand about mocking
+    Date.now = jest.fn().mockReturnValue(currentDate);
+
+    queueMarkAsRead(eg.selfAuth, [13, 14, 15]);
+
+    // $FlowFixMe Make flow understand about mocking
+    Date.now = jest.fn().mockReturnValue(secondCall);
+
+    queueMarkAsRead(eg.selfAuth, [16, 17, 18]);
+
+    expect(messagesFlags.default).toHaveBeenCalledTimes(2);
+  });
+});

src/api/queueMarkAsRead.js

@@ -5,6 +5,15 @@ import messagesFlags from './messages/messagesFlags';
 let unsentMessageIds = [];
 let lastSentTime = 0;
 
+/**
+ * Exported so that it can be used in test
+ * See queueMarkAsRead-test.js
+ */
+export const resetAll = () => {
+  unsentMessageIds = [];
+  lastSentTime = 0;
+};
+
 const processQueue = (auth: Auth) => {
   if (Date.now() - lastSentTime > 2000) {
     messagesFlags(auth, unsentMessageIds, 'add', 'read');