[RxJava 2.0.0-RC2] Observable.delay doesn't respect the provided Scheduler

[nsk-mironov]

public class DelayBug {
  public static void main(String[] args) throws Exception {
    final CountDownLatch latch = new CountDownLatch(1);

    Observable.<String>error(new Exception())
        .delay(100, TimeUnit.MILLISECONDS, Schedulers.io())
        .doOnError(throwable -> System.out.println("onError @ " + Thread.currentThread().getName()))
        .onErrorResumeNext(Observable.empty())
        .doAfterTerminate(latch::countDown)
        .subscribe();

    latch.await();
  }
}

Output:

onError @ main

Expected output:

onError @ RxCachedThreadScheduler-1

[akarnokd]

Please check the available overloads for the feature you are looking for.

[nsk-mironov]

I don't want to delay the error, but I still want to receive onError callback on the provided scheduler. This is how RxJava 1 works (OperatorDelay.java#L66-L78). I think the following code ObservableDelay.java#L89-L105 should be:

@Override
public void onError(final Throwable t) {
    w.schedule(new Runnable() {
        @Override
        public void run() {
            try {
                actual.onError(t);
            } finally {
                w.dispose();
            }
        }
    }, delayError ? delay : 0, unit);
}

[akarnokd]

PR welcome.

[nsk-mironov]

Closed via #4522