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[Bug]: useFakeTimers on setTimeout within a promise

See original GitHub issue

Version

27.1.0

Steps to reproduce

test('should let me test sleep', () => {
    jest.useFakeTimers();

    const expectedTimeout = 4;

    const sleep = (seconds) =>
        new Promise((resolve) => setTimeout(resolve, seconds * 1000));

    sleep(expectedTimeout);

    expect(setTimeout)
        .toHaveBeenCalledTimes(1)
        .toHaveBeenCalledWith(expect.any(Function), expectedTimeout * 1000);
});

Test passes on jest 26, but fails on 27 unless legacy is passed.

Receive this error instead.

Cannot read property 'message' of undefined
TypeError: Cannot read property 'message' of undefined

Based on the documentation, I expected setTimeout to be a mock object as it was previously. Thank you for taking a look!

Expected behavior

The test should pass.

Actual behavior

Exception from reproduction steps occurs.

Additional context

No response

Environment

System:
    OS: macOS 11.5.2
    CPU: (12) x64 Intel(R) Core(TM) i7-9750H CPU @ 2.60GHz
  Binaries:
    Node: 12.22.5 - ~/.nvm/versions/node/v12.22.5/bin/node
    Yarn: 1.22.11 - ~/.nvm/versions/node/v12.22.5/bin/yarn
    npm: 6.14.14 - ~/.nvm/versions/node/v12.22.5/bin/npm
  npmPackages:
    jest: 27.1.0 => 27.1.0

Issue Analytics

State:
Created 2 years ago
Comments:5 (2 by maintainers)

Top GitHub Comments

1reaction

sigveiocommented, Aug 31, 2021

jest.spyOn(global, 'setTimeout');

Note that this has to come after jest.useFakeTimers()

0reactions

github-actions[bot]commented, Oct 1, 2021

This issue has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs. Please note this issue tracker is not a help forum. We recommend using StackOverflow or our discord channel for questions.

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