jest test is not exiting after test passes with react-test-renderer - react-native

Question

I have a toMatchSnapshot test on a simple component with React Native 0.68.2/jest 29.0. Here is the component SysError:
import React, {useState, useContext, Component} from 'react';
import {Platform, Button, Text, TouchableOpacity } from 'react-native';
export default function SysError({route}) {
const message = route.params.message;
return (
<Text>{message}. System NOT available right now. Try again later</Text>
)
};
Here is the SysError.test.js:
import React from 'react';
import renderer from 'react-test-renderer'; //<<==v17.0.2
import SysError from './SysError';
it ('describe SysError page view with no message', () => {
const route = {params: {message:"noth"}};
const tree = renderer.create(<SysError route={route} />).toJSON();
expect(tree).toMatchSnapshot();
})
After yarn test --detectOpenHandle, test passes but is not exiting by itself. Here is the error for component SysError:
Jest has detected the following 2 open handles potentially keeping Jest from exiting:
● MESSAGEPORT
1 | import React from 'react';
> 2 | import renderer from 'react-test-renderer';
| ^
3 | import SysError from './SysError';
4 |
5 | it ('describe SysError page view with no message', () => {
at node_modules/scheduler/cjs/scheduler.development.js:178:17
at Object.<anonymous> (node_modules/scheduler/cjs/scheduler.development.js:13:3)
at Object.require (node_modules/scheduler/index.js:6:20)
at require (node_modules/react-test-renderer/cjs/react-test-renderer.development.js:19:19)
at Object.<anonymous> (node_modules/react-test-renderer/cjs/react-test-renderer.development.js:13:3)
at Object.require (node_modules/react-test-renderer/index.js:6:20)
at Object.<anonymous> (src/components/app/SysError.test.js:2:1)
at asyncGeneratorStep (node_modules/#babel/runtime/helpers/asyncToGenerator.js:3:24)
at _next (node_modules/#babel/runtime/helpers/asyncToGenerator.js:25:9)
There is no async call in SysError.js and what is missing here?

Answer 1

This seems to be caused by the scheduler package.
It was supposed to be fixed in React 17.1.0 but that never came around. There was even an issue for it.
What you can do, is any of the following:
Upgrade to React 18+ (Expo SDK 46+) and the corresponding RN version.
Use delete global.MessageChannel; which should do in your file where the issue is occurring.
Install the react-16-node-hanging-test-fix with yarn add react-16-node-hanging-test-fix or npm install react-16-node-hanging-test-fix which was made by a React core team member Dan Abramaov. This package essentially does step 2 with greater safety due to some checks and stuff.