Support aborting when() using AbortSignal

[deadbeef84]

I know the promise returned by when() can be aborted using promise.cancel(), but I think the new standard mechanism for aborting async operations is using AbortController / Signal.

I suggest adding a signal parameter to the options object:

const abortController = new AbortController()
await when(() => ..., { signal: abortController.signal })
// abortController.abort() would make the promise reject

[mweststrate]

Sounds like a great idea. PR welcome :)

[deadbeef84]

#3551

[spaguette]

I was wondering if we could do the same with the MobX flow (e.g. in case you have some ongoing HTTP requests you'd like to cancel)?

[deadbeef84]

I haven't used MobX flow, but normally you would just pass a signal to your function, and forward it when calling async functions.