@Test public void testUnsubscribeAfterTake() { Subscription s = mock(Subscription.class); TestObservable w = new TestObservable(s, "one", "two", "three"); @SuppressWarnings("unchecked") Observer<String> aObserver = mock(Observer.class); Observable<String> take = Observable.create(take(w, 1)); take.subscribe(aObserver); // wait for the Observable to complete try { w.t.join(); } catch (Exception e) { e.printStackTrace(); fail(e.getMessage()); } System.out.println("TestObservable thread finished"); verify(aObserver, times(1)).onNext("one"); verify(aObserver, never()).onNext("two"); verify(aObserver, never()).onNext("three"); verify(s, times(1)).unsubscribe(); }