@Test(groups = "standalone") public void testToObservableError() { final TestSubscriber<Response> tester = new TestSubscriber<>(); try (AsyncHttpClient client = asyncHttpClient()) { Observable<Response> o1 = AsyncHttpObservable.toObservable(() -> client.prepareGet("http://gatling.io/ttfn")); o1.subscribe(tester); tester.awaitTerminalEvent(); tester.assertTerminalEvent(); tester.assertCompleted(); tester.assertNoErrors(); List<Response> responses = tester.getOnNextEvents(); assertNotNull(responses); assertEquals(responses.size(), 1); assertEquals(responses.get(0).getStatusCode(), 404); } catch (Exception e) { Thread.currentThread().interrupt(); } }