Jest did not exit one second after the test run has completed using express

Question

I'm using JEST for unit testing my express routes.

While running the yarn test all my test case are getting passed, but I'm getting an error

Jest did not exit one second after the test run has completed.

This usually means that there are asynchronous operations that weren't stopped in your tests. Consider running Jest with `--detectOpenHandles` to troubleshoot this issue.

I used async & done, but still it throws the above error.

Below is my spec code. Please help

routes.spec.ts

const request = require('supertest');
describe('Test the root path', () => {
  const app = require('./index');

  test('GET /gql/gql-communication-portal/release-notes', async (done) => {
    const response = await request(app).get('/gql/gql-communication-portal/release-notes');
    expect(response.status).toBe(200);
    done();
  });
});

Answer 1

My problem was solved by this code:

beforeAll(done => {
  done()
})

afterAll(done => {
  // Closing the DB connection allows Jest to exit successfully.
  mongoose.connection.close()
  done()
})

Answer 2

I have added this line to package.json

It worked for me

jest --runInBand --detectOpenHandles --forceExit

Answer 3

For me it was a different issue I was using supertest to test routes itself so I had to close the connection to the server itself.

afterAll(done => {
    server.close();
    done();
});

You can start server in beforeAll block and close in after all:

beforeAll(() => {
   server = app.listen(someRandomNumberHere); // Random number is needed to avoid using same port in different tests if you run in parallel
})

afterAll(() => {
   server.close()
})

If this is not the case for you this issue might have something for you

Answer 4

On my side, I just separate app.listen() from my app. So with express, your app finish with an export.

// index.js
module.exports = app;

And just create another file to listen the port.

// server.js
const app = require('./index')
app.listen(...)

And if you import just the index (app index.js) in your tests, it should work with no extra config. Of course your need to adjust the start of your express app. It should use now server.js.

Answer 5

I was having the same issue but in my package.json file i added "test": "jest --detectOpenHandles" and ran npm test --detectOpenHandles. I didn't get the error message this time. Maybe you can try doing that.

Answer 6

Adding

jest.useFakeTimers();

at the beginning of the test suite fixed it for me.

Might come from timers defined in components part of the render (like throttled buttons, mocks etc..).

Answer 7

This worked for me

const mongoose = require('mongoose');
    afterAll(async(done) => {
  // Closing the DB connection allows Jest to exit successfully.
  try {
    await mongoose.connection.close();
    done()
  } catch (error) {
    console.log(error);
    done()
  }
  // done()
})

Answer 8

For Firebase I had to call cleanup()

import {
    assertFails,
    assertSucceeds,
    initializeTestEnvironment,
    RulesTestEnvironment,
} from "@firebase/rules-unit-testing";
import { doc, setDoc } from "firebase/firestore";

it('creates a new user document in firebase', async () => {
    const testEnv = await initializeTestEnvironment({
        projectId: "appname-test",
        firestore: {
            host: 'localhost',
            port: 8088
        }
    });

    const alice = testEnv.authenticatedContext("alice");

    await assertSucceeds(setDoc(doc(alice.firestore(), "users", "alice"), {
        fname: "Alice",
        lname: "Wonderland",
        dob: "18/01/1999",
        email: "alice@example.com"
    }));

    return await testEnv.cleanup();
});

Answer 9

You can try this one

"test": "jest --runInBand --force-exit"

Answer 10

I was running into the same issue but, I was using the pg module with my NodeJS Express app. I want to post this for those using this stack as well if it helps them.

Essentially, supertest creates a server connection, which some people might get the TCPSERVERWRAP error because it doesn't get closed, regardless whether I use async/await or the jest done callback. So, this has to be closed after each test. On top of that, the database connection remains open so I mocked it.

Closing the server connection and mocking pg together solved the error for me.

products.tests.ts

import request from 'supertest'
import { Pool } from 'pg'
import app from '../app'
import type { Server } from 'http'

jest.mock('pg')

const { ROUTE_VERSION = '/v1' } = process.env
const route = (path: string) => [ROUTE_VERSION, path].join('')
const pool = new Pool()
let server: Server

beforeEach(() => {
   server = app.listen(4000)
})

afterEach(() => {
   server.close()
})

describe('GET /products', () => {
   it('returns array of products', async () => {
      await request(server)
         .get(route('/products'))
         .expect(200)
         .expect((res) => {
            expect(pool.query).toBeCalledTimes(1)
            expect(res.body).toBeInstanceOf(Array)
            expect(res.body).not.toHaveLength(0)
         })
   })
})

UPDATE: Meant to use beforeEach and afterEach to close the server after EACH test, otherwise, it still remains open like before.

UPDATE 2: Using async/await otherwise, it will always pass because request is asynchronous and doesn't complete unless you wait for it to finish.

Answer 11

I got the same problem due to not closing the database connection after all the test cases runs. It can be done using jest.config.js and adding a new file to root folder which will globally close the database connection after all the test cases.

In jest.config.js file add the following to the module.exports ,

module.exports = {
   setupFilesAfterEnv: ['<rootDir>/src/runAfterAllTests.ts'],
}

Then add runAfterAllTests.ts to src folder.

runAfterAllTests.ts will globally close the db connection. For mongodb it should be something like this.

import { client } from './database/connect';

global.afterAll(async () => {
  await client.close();
});

This will close the db connection after all the tests and fix the issue.

Answer 12

In NestJs apps, where you have something like

app = moduleFixture.createNestApplication();
await app.init();

Just add this in your test file

afterAll(done => {
    app.close()
    done()
})

You can as well use async

afterAll(async() => {
    await app.close()
})

Answer 13

My problem is that I use Sequilize ORM and I forgot to close it at the end of testing inside the afterAll function callback.

This is my code:

afterAll((done) => {
    MatrixTableHeaderCol.destroy({
        where: {},
        force: true
    }).then(() => {
        done();
    });
});