waitFor is not working with jest fakeTimers

[Geoffroy Vincent]

• @testing-library/react version: v14.0.0
• Testing Framework and version:
  • jest version 29.5.0
• DOM Environment:
  • jsdom version 29.5.0

Relevant code or config:

Here is the test code (designed to fail):

import {renderHook, waitFor} from "@testing-library/react";
import {useState} from "react";

beforeAll(() => {
  jest.useFakeTimers();
});

describe("dummy test", () => {
  it("I will fail", async () => {
    const { result } = renderHook(() => {
      const [data] = useState(false);
      return { data };
    });

    await waitFor(
      () => {
        // Will obviously fail, but should do so after 5s.
        expect(result.current.data).toBeTruthy();
      },
      { timeout: 5000 }
    );
  });
});

What you did:

Running tests with npm run test.

What happened:

The test failed nearly instantly.

However, if I comment the jest.useFakeTimers() line, it works as expected.

Reproduction:

I made a basic repro here.

Problem description:

Using jest fake timers breaks the waitFor function.

[Jacek Tomaszewski]

I guess it's the same as #1187 . Jest since v27 uses new implementation of fake timers, and as described in #1187, testing library doesn't work with them as of the moment.