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

[flextremedev]

Hi, I followed the docs testing section and when I run the tests jest logs:

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

This is my code:

import * as React from 'react';
import {QueryClient, QueryClientProvider, useQuery} from 'react-query';
import {renderHook} from '@testing-library/react-hooks';
export function useCustomHook() {
  const {data} = useQuery('customHook', () => 'Hello');
  return data;
}

const queryClient = new QueryClient();
const wrapper: React.FC = ({children}) => (
  <QueryClientProvider client={queryClient}>{children}</QueryClientProvider>
);
it('should work', () => {
  const {result} = renderHook(() => useCustomHook(), {wrapper});

  expect(result.current).toEqual('Hello');
});

Am I missing something or is anyone else experiencing this?
Thanks in advance!

[TkDodo]

I put your code in a codesandbox: https://codesandbox.io/s/react-query-basic-testing-nh6tv

what was missing for me was waiting for the query to transition into success state, I did what with waitFor. Even though you resolve the promise immediately, there will still be one render cycle were things are loading

[smikheiev]

@flextremedev @TkDodo So did you guys figure out if it's a bug or not and the way to fix it?

[TkDodo]

I'm seeing this:

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.

and then I do what jest says and run it with --detectOpenHandles and then it just works, without any additional output 🤔

could be related to this jest issue: jestjs/jest#9473 (comment)

and applying the workaround described there made it work for me:

- "test": "jest",
+ "test": "jest --detectOpenHandles --forceExit",

[flextremedev]

that's what I've done. but it's not very satisfying as it's generally bad practice to use forceExit.

[gabrielbull]

That's what I do too, but it's not a real solution. Should this discussion be moved to issues?

[TkDodo]

Yes, feel free to open an issue. I personally don’t know enough about react native or the internal timers to be of much help here

[gabrielbull]

I'm having the same issue

[dkershner6]

I am as well.

"@testing-library/react-native": "^7.1.0",
"react-native": "https://github.com/expo/react-native/archive/sdk-38.0.2.tar.gz",
"react-query": "^3.6.0",

[flextremedev]

Discussed further in #1847