@Test
public void testDefer() throws Throwable {
Supplier<Observable<String>> factory = mock(Supplier.class);
Observable<String> firstObservable = Observable.just("one", "two");
Observable<String> secondObservable = Observable.just("three", "four");
when(factory.get()).thenReturn(firstObservable, secondObservable);
Observable<String> deferred = Observable.defer(factory);
verifyZeroInteractions(factory);
Subscriber<String> firstObserver = TestHelper.mockSubscriber();
deferred.subscribe(firstObserver);
verify(factory, times(1)).get();
verify(firstObserver, times(1)).onNext("one");
verify(firstObserver, times(1)).onNext("two");
verify(firstObserver, times(0)).onNext("three");
verify(firstObserver, times(0)).onNext("four");
verify(firstObserver, times(1)).onComplete();
Subscriber<String> secondObserver = TestHelper.mockSubscriber();
deferred.subscribe(secondObserver);
verify(factory, times(2)).get();
verify(secondObserver, times(0)).onNext("one");
verify(secondObserver, times(0)).onNext("two");
verify(secondObserver, times(1)).onNext("three");
verify(secondObserver, times(1)).onNext("four");
verify(secondObserver, times(1)).onComplete();
}
@Test
public void testDeferFunctionThrows() {
Supplier<Observable<String>> factory = mock(Supplier.class);
when(factory.get()).thenThrow(new TestException());
Observable<String> result = Observable.defer(factory);
Observer<String> o = mock(Observer.class);
result.subscribe(o);
verify(o).onError(any(TestException.class));
verify(o, never()).onNext(any(String.class));
verify(o, never()).onComplete();
}