debounce durationSelector param has incorrect typings

[patsissons]

RxJS version:
5.5.3

Code to reproduce:

Observable
  .of('foo')
  .debounce(() => Observable.of('bar').delay(1000))
  .subscribe();

Expected behavior:
no compiler errors

Actual behavior:
error TS2345: Argument of type '() => Observable<string>' is not assignable to parameter of type '(value: string) => SubscribableOrPromise<number>'.

Additional information:
It looks like this was previously just working due to a type checking deficiency that has been corrected (not sure what has changed recently, possibly the 5.5.2 to 5.5.3 update?)

This can be easily patched by just projecting the duration selector to a number, but it's not very elegant and it make for very confusing looking observable composition.

Observable
  .of('foo')
  .debounce(() => Observable.of('bar').delay(1000).map(() => 0))
  .subscribe();

The debounce operator does not actually use the value of the duration selector, only its asynchrony to manipulate the debounce operator.

The proper typing should be durationSelector: (value: T) => SubscribableOrPromise<any> (or something more appropriate if any is not acceptable).

[lock]

This thread has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.