CODEWITHSUNDEEP
javascriptnode.jsexpressjestjs
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Reputation: 6461

Jest - A worker process has failed to exit gracefully and has been force exited

I have a test file called integration.test.js

import app from "../app";
import request from "supertest";

describe("testing /users", () => {
  const app = request(app);
  // 5 test cases here. Both use app for api testing
})

describe("testing /images", () => {
  const app = request(app);
  // 6 test cases here. Both use app for api testing
})

describe("testing /blogs", () => {
  const app = request(app);
  // 7 test cases here. Both use app for api testing
})

When I run jest to run the test cases, it returns a warning

A worker process has failed to exit gracefully and has been force exited. This is likely caused by tests leaking due to improper teardown. Try runn
ing with --detectOpenHandles to find leaks. Active timers can also cause this, ensure that .unref() was called on them.

It also takes around 5 seconds to complete the testing, which seems to be slow

How can I fix the warning and the time of running the test cases?

app.js

import express from "express";

const app = express();
const PORT = process.env.PORT || 3000;

app.use(express.json());

app.get("/", (req, res) => {
  res.status(200).send("Hello");
});

app.post("/users", (req, res) => {...});
app.post("/images", (req, res) => {...});
app.post("/blogs", (req, res) => {...});


app.listen(PORT, () => {
  console.log(`Server running on ${PORT}`);
});

export default app;

Upvotes: 10

Views: 26364

Answers (3)

Wildan Maulana Syahidillah
Wildan Maulana Syahidillah

Reputation: 904

You will need to close the HTTP server on test teardown.

Instead of exporting the express.js app, you need to export the http.Server created from app.listen.

export const server = app.listen(PORT, () => {
  console.log(`Server running on ${PORT}`);
});

Pass server instead of app into supertest, then on the tests afterAll hook, call server.close():

import { server } from "../app";
import request from "supertest";

describe("testing /users", () => {
  const app = request(server);

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

  // 5 test cases here. Both use app for api testing
})

Upvotes: 2

Michael Durrant
Michael Durrant

Reputation: 96544

We struggled with this for a couple of days and finally came up with a fix which works both locally and in our CI (github actions). We were experiencing this issue with using create-react-app plus Firebase-firestore

The trick was that we needed both of the params below to both suppress the message and force the exit.

"test": "react-scripts test --detectOpenHandles --forceExit",

Whether this is covering up a more significant issue remains to be seen

Upvotes: 16

Tin Po Chan
Tin Po Chan

Reputation: 125

I am guessing it's related to asynchronous behaviour, maybe try to use async for test case.

Example:

const supertest = require('supertest')
const app = require('../app')
const api = supertest(app)

describe("testing /users", () => {
    test('get all users', async () => {
        await api
            .get('/api/users')
            .expect(200)
            .expect('Content-Type', /application\/json/)
    })
})

Upvotes: 1

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