tests with waitFor or findBy only pass with concurrentRoot: false

[gfreeman-karmak]

We're having an odd issue since upgrading to v13. We had a lot of tests suddenly break, and they were all tests that depended on waitFor, whether using it directly or using a findBy query. For some reason when the waitFor loop advances jest timers, the screen is no longer updating, so expectations and queries never resolve.

What I found fixed the issue for now is to set concurrentRoot: false, but that can only be temporary until react v19.

Interestingly, I also tried editing the wait-for.js code directly to wrap jest.advanceTimersByTime(interval); in act and that also worked. However it appears IS_REACT_ACT_ENVIRONMENT is purposely set to false, so I have to assume the omission of act is intentional, so I don't understand why concurrentRoot: true would suddenly break the tests.

I wrote a small test to illustrate:

import { afterEach, expect, jest, test } from '@jest/globals';
import { fireEvent, render, screen } from '@testing-library/react-native';
import { useEffect, useState } from 'react';
import { Pressable, View } from 'react-native';

jest.useFakeTimers();

const onPress = jest.fn();

function MockView() {
    const [buttonVisible, setButtonVisible] = useState(false);

    useEffect(() => {
        setTimeout(() => setButtonVisible(true), 100);
    }, []);

    return (
        <View>
            {buttonVisible && <Pressable accessibilityRole='button' onPress={onPress}>Button</Pressable>}
        </View>
    );
}

afterEach(() => {
    jest.clearAllMocks();
});

test.each([true, false])('button press, concurrentRoot: %s', async (concurrentRoot) => {
    render(<MockView />, { concurrentRoot });
    fireEvent.press(await screen.findByRole('button'));
    expect(onPress).toHaveBeenCalled();
});

The test with concurrentRoot: false passes with no issue, but in the concurrentRoot: true test, findBy never finds the button: Unable to find an element with role: button.

Any ideas?

react: 18.3.1
react-native: 0.77.0
react-test-renderer: 18.3.1
@testing-library/react-native: 13.0.1
jest: 29.7.0

Thanks

[flaviomsb]

I'm experiencing the same issue after the recent upgrade to react-native 0.77.1 and @testing-library/react-native: 13.0.1. I am also on react 18.3.1 and jest 29.7.0.