useFakeTimers doesn't fake performance.now()

[panrafal]

As using perfomance.now() is more robust for timeouts than Date.now(), it'd be nice if creating a clock would "pause" or synchronize performance.now to provided now value and calling clock.tick would move it.

[mroderick]

Why would you use Date.now() or performance.now for setTimeout?

Can you give a usage example?

[panrafal]

@mroderick "for timeouts" I've meant when you check if enough time has passed:

var started = performance.now();

function calledLater() {
  if (performance.now() - started > 5000) {
    // do something
  }
}

In my use case I'm checking if some visual feedback was visible to the user long enough before removing it. Performance.now() guarantees it'll only go forward and it's not possible to break it by adjusting the system clock.

I've fixed this for myself by stubbing performance.now() with Date.now() sinon.stub(performance, 'now', Date.now)

Since posting this I've found that timers are handled by lolex, so probably it's better to move this issue there?

[mroderick]

Why not just use setTimeout?

setTimeout(function calledLater(){
    // do something
}, 5000);

[panrafal]

It's not an operation that should be run after some time, but a check if sufficient amount of time has passed.

[mroderick]

It's not an operation that should be run after some time, but a check if sufficient amount of time has passed.

setTimeout guarantees that sufficient time has passed, that's what it's for ...

[mroderick]

In any case, pull requests to lolex would be most welcome

[mroderick]

I am closing the issue here. If you feel like contributing to lolex, please open a pull request in that repository.