Fix unhandled promise rejection in onceWithCleanup

[IceTank]

From MDN:

Returns an equivalent Promise with its finally handler set to the specified function. If the handler throws an error or returns a rejected promise, the promise returned by finally() will be rejected with that value instead

So finally will throw an unhandled promise rejection if the task promise rejects. Causing a un-catchable promise rejection on the onceWithCleanup function

[extremeheat]

This does not seem right. You're silently letting this fail.

[IceTank]

The promise returned by finally is a copy off the promise the task itself will return. This is why there is a unhandled promise rejection in the first place. No one is handling the promise returned by finally because it is also returned by the promise in task.

[IceTank]

Altho this does not work with the linter. Maybe promise.catch(() => {}).finally(() => ...) would be better?

[extremeheat]

You’re right, I missed that. It’s a chained promise, so it should be catching error removing the event (if I’m not mistaken)

[IceTank]

@extremeheat Changed it

[extremeheat]

Why did you change it ? I said you were right.

[IceTank]

I changed it because the old version caused a lint error. This version works.