[drdaeman]

> Indeed, so why doesn't setTimeout internally do that?

Given that `setTimeout` is a part of JavaScript's ancient reptilian brain, I wouldn't be surprised it doesn't do those checks just because there's some silly compatibility requirement still lingering and no one in the committees is brave enough to make a breaking change.

(And then, what should setTimeout do if delay is NaN? Do nothing? Call immediately? Throw an exception? Personally I'd prefer it to throw, but I don't think there's any single undeniably correct answer.)

Given the trend to move away from the callbacks, I wonder why there is no `async function sleep(delay)` in the language, that would be free to sort this out nicely without having to be compatible with stuff from '90s. Or something like that.

[erinaceousjones]

I think it's more likely that it's just "undefined behaviour" and up to the implementers of the JavaScript engines. Given that modern browsers do limit and throttle how much you can do with setTimeout in some situations (try to use setTimeout on a page after you've switched to a VR context! More than like 120hz and it'll just.... Not run the timeout anymore, from experience with Chrome).

The browser devs have decided it's acceptable to change the behaviour of setTimeout in some situations.

https://developer.chrome.com/blog/timer-throttling-in-chrome...