vi.useFakeTimers() doesn't fake performance by default despite docs claiming it does

[a-non-a-mouse]

Documentation is

• Missing
• Outdated
• Confusing
• Not sure?

Explain in Detail

Docs state that toFake defaults to "everything available globally except nextTick and queueMicrotask", which should include performance.

However, performance.now() is not faked unless explicitly specified:

import { beforeEach, expect, it, vi } from 'vitest';

beforeEach(() => {
  vi.useFakeTimers();
});

it('fails - performance.now not advancing', () => {
  const start = performance.now();
  vi.advanceTimersByTime(100);
  expect(performance.now() - start).toBe(100); // fails: expected 100, got 0.1....
});

Requires:

vi.useFakeTimers({ toFake: ['performance'] });

Similarly, https://vitest.dev/api/vi states:

If fake timers are enabled, this method simulates a user changing the system clock (will affect date related API like hrtime, performance.now or new Date())

and

vi.useFakeTimers() does not automatically mock process.nextTick and queueMicrotask. But you can enable it by specifying the option in toFake argument: vi.useFakeTimers({ toFake: ['nextTick', 'queueMicrotask'] }).

Which appear to be wrong / incomplete

Your Suggestion for Changes

Update docs to remove performance, possibly others, from list of default mocked timers

Reproduction

No response

[sheremet-va]

I cannot confirm this: https://stackblitz.com/edit/vitest-dev-vitest-kwnkzsam?file=test%2Fbasic.test.ts&initialPath=__vitest__/

Perhaps, you set fakeTimers in the config?

[github-actions]

Hello @a-non-a-mouse. Please provide a minimal reproduction using a GitHub repository or StackBlitz (you can also use examples). Issues marked with needs reproduction will be closed if they have no activity within 3 days.

[a-non-a-mouse]

Issue was we had 2 conflicting versions and vitest 2.1.8 was running, which had this behavior