feat(rule): do not check for the complete method to be called since i…

[nivekcode]

On Twitter people pointed out that we don't need to call the complete method of the destroy$.

I just had a look into the RxJS source code and saw that take until doesn't only unsubscribe from the source but also from the notifier.

  constructor(private notifier: Observable<any>) {
  }

  call(subscriber: Subscriber<T>, source: any): TeardownLogic {
    const takeUntilSubscriber = new TakeUntilSubscriber(subscriber);
    const notifierSubscription = subscribeToResult(takeUntilSubscriber, this.notifier);
    if (notifierSubscription && !takeUntilSubscriber.seenValue) {
      takeUntilSubscriber.add(notifierSubscription);
      return source.subscribe(takeUntilSubscriber);
    }
    return takeUntilSubscriber;
  }
}

Not only the source but also the notifier gets unsubscribed. So, therefore, we don't need to call complete. @macjohnny, @tomastrajan what do you think?

[macjohnny]

@kreuzerk good point, I think you are right. Some while ago I tested the effect of omitting the this.destroy$.complete() call, and there were no excessive Subscribers in the heap, but since this pattern is also used e.g. in
https://github.com/angular/components/blob/0ed9416ab9690be219eab799042777f31e5df823/src/cdk/layout/breakpoints-observer.ts#L52-L56
I was too afraid to remove it ;-)

So I think we should include your change.

[nivekcode]

Here's some further information about the topic:
https://twitter.com/Michael_Hladky/status/1193641068635590656

[macjohnny]

LGTM