Cannot call Express Next function after throwing Error (TypeScript)

[ShinJustinHolly3317]

Env:

typescript 4.7.4
Node 14
Supertest 6.2.4
Jest 28.1.3
Express 4.18.1
Express-async-Handler 1.2.0

Test Code

import server, { app } from '/server.ts'

const mockGetCache = jest.fn();
const mockSetCache = jest.fn();

// This is mocking class
jest.mock('../../src/infra/clients/memcached-client', () => jest.fn().mockImplementation(() => ({
  getCache: mockGetCache,
  setCache: mockSetCache,
})));

it('POST cardData Error', async () => {
    mockGetCache.mockImplementation(() => {
      throw new Error('test-error in POST cardData');
    });

    const response = await request(app)
      .post('/api/v1/ad/cardData')
      .send(fakeCardData);

    expect(response.statusCode).toBe(500);
    expect(response.body).toEqual({ code: 9999, message: 'test-error in POST cardData' });
  });

Application code

1. server.ts

// ...
// set up routes
app.use('/api/v1', routes);

// set up error handler
app.use(errorHandler);
// ....

2. card data route

// ....
const router = express.Router();

router.post('/', asyncHandler(postCardDataHandler));

export default router;

3. postCardDataHandler.ts

  try {
    const { cardId } = req.body;
    const { appId } = req.body;

    // init repository
    const cacheClient = new MemcachedClient();
    const memcachedCardRepository = new MemcachedCardRepository(cacheClient);
    const postCardUsecase = new PostCardUsecase(memcachedCardRepository);

    // execute usecase
    const keywords = await postCardUsecase.exec(adId, appId);

    return res.status(200).json(keywordsDto);
  } catch (err) {
    console.error('[some warning]', err)
    return next(err)
  }
  

Simple workflow
My code doesn't respond 500 to client directly. I use express error handler to catch all error and responds error to client here.
So I also use express-async-handler to catch unexpected error, which will call next() and let error-handler catch the error.

Problem:
When I start server, everything works fine with both postman, curl, or my Frontend Website and Mobile.
However it went into Timeout problem when I do integration test with supertest.
Below is log

  ● ad server unit test ›POST cardData Error

    thrown: "Exceeded timeout of 5000 ms for a test.
    Use jest.setTimeout(newTimeout) to increase the timeout value, if this is a long-running test."

Possible reason

next function not working normally.

After digging deep to the express-async-handler, and I found that everything is good with it.
At the final step express-async-handler also call next(err), but my error-handler didn't catch the err.

found similar issue here #529

update

I tried remove express router, and use the handler directly by app.post(...) in server.ts
like

// ...
// set up routes
app.use('/api/v1',(req, res, next) => {
  try {
     //...
  } catch (err) {
     console.log('[handler Error]', err)
     return next(err)
  }

});

// set up error handler
app.use(errorHandler);
// ....

This will work correctly.
Still have no clue why.

anyone can save me?

[ShinJustinHolly3317]

This issue is because of jest.useFakeTimer will probably mock out some event loop function under next().
Prevent using jest.useFakeTimer will fix this issue.