/**
* Copyright 2014 Netflix, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package rx.subjects;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertFalse;
import static org.junit.Assert.assertNull;
import static org.junit.Assert.assertTrue;
import static org.junit.Assert.fail;
import static org.mockito.Matchers.any;
import static org.mockito.Matchers.anyString;
import static org.mockito.Mockito.inOrder;
import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.never;
import static org.mockito.Mockito.times;
import static org.mockito.Mockito.verify;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicReference;
import org.junit.Test;
import org.mockito.InOrder;
import org.mockito.Mockito;
import rx.Observer;
import rx.Subscription;
import rx.exceptions.CompositeException;
import rx.exceptions.OnErrorNotImplementedException;
import rx.exceptions.TestException;
import rx.functions.Action1;
import rx.observers.TestSubscriber;
public class AsyncSubjectTest {
private final Throwable testException = new Throwable();
@Test
public void testNeverCompleted() {
AsyncSubject<String> subject = AsyncSubject.create();
@SuppressWarnings("unchecked")
Observer<String> observer = mock(Observer.class);
subject.subscribe(observer);
subject.onNext("one");
subject.onNext("two");
subject.onNext("three");
verify(observer, Mockito.never()).onNext(anyString());
verify(observer, Mockito.never()).onError(testException);
verify(observer, Mockito.never()).onCompleted();
}
@Test
public void testCompleted() {
AsyncSubject<String> subject = AsyncSubject.create();
@SuppressWarnings("unchecked")
Observer<String> observer = mock(Observer.class);
subject.subscribe(observer);
subject.onNext("one");
subject.onNext("two");
subject.onNext("three");
subject.onCompleted();
verify(observer, times(1)).onNext("three");
verify(observer, Mockito.never()).onError(any(Throwable.class));
verify(observer, times(1)).onCompleted();
}
@Test
public void testNull() {
AsyncSubject<String> subject = AsyncSubject.create();
@SuppressWarnings("unchecked")
Observer<String> observer = mock(Observer.class);
subject.subscribe(observer);
subject.onNext(null);
subject.onCompleted();
verify(observer, times(1)).onNext(null);
verify(observer, Mockito.never()).onError(any(Throwable.class));
verify(observer, times(1)).onCompleted();
}
@Test
public void testSubscribeAfterCompleted() {
AsyncSubject<String> subject = AsyncSubject.create();
@SuppressWarnings("unchecked")
Observer<String> observer = mock(Observer.class);
subject.onNext("one");
subject.onNext("two");
subject.onNext("three");
subject.onCompleted();
subject.subscribe(observer);
verify(observer, times(1)).onNext("three");
verify(observer, Mockito.never()).onError(any(Throwable.class));
verify(observer, times(1)).onCompleted();
}
@Test
public void testSubscribeAfterError() {
AsyncSubject<String> subject = AsyncSubject.create();
@SuppressWarnings("unchecked")
Observer<String> observer = mock(Observer.class);
subject.onNext("one");
subject.onNext("two");
subject.onNext("three");
RuntimeException re = new RuntimeException("failed");
subject.onError(re);
subject.subscribe(observer);
verify(observer, times(1)).onError(re);
verify(observer, Mockito.never()).onNext(any(String.class));
verify(observer, Mockito.never()).onCompleted();
}
@Test
public void testError() {
AsyncSubject<String> subject = AsyncSubject.create();
@SuppressWarnings("unchecked")
Observer<String> observer = mock(Observer.class);
subject.subscribe(observer);
subject.onNext("one");
subject.onNext("two");
subject.onNext("three");
subject.onError(testException);
subject.onNext("four");
subject.onError(new Throwable());
subject.onCompleted();
verify(observer, Mockito.never()).onNext(anyString());
verify(observer, times(1)).onError(testException);
verify(observer, Mockito.never()).onCompleted();
}
@Test
public void testUnsubscribeBeforeCompleted() {
AsyncSubject<String> subject = AsyncSubject.create();
@SuppressWarnings("unchecked")
Observer<String> observer = mock(Observer.class);
Subscription subscription = subject.subscribe(observer);
subject.onNext("one");
subject.onNext("two");
subscription.unsubscribe();
verify(observer, Mockito.never()).onNext(anyString());
verify(observer, Mockito.never()).onError(any(Throwable.class));
verify(observer, Mockito.never()).onCompleted();
subject.onNext("three");
subject.onCompleted();
verify(observer, Mockito.never()).onNext(anyString());
verify(observer, Mockito.never()).onError(any(Throwable.class));
verify(observer, Mockito.never()).onCompleted();
}
@Test
public void testEmptySubjectCompleted() {
AsyncSubject<String> subject = AsyncSubject.create();
@SuppressWarnings("unchecked")
Observer<String> observer = mock(Observer.class);
subject.subscribe(observer);
subject.onCompleted();
InOrder inOrder = inOrder(observer);
inOrder.verify(observer, never()).onNext(null);
inOrder.verify(observer, never()).onNext(any(String.class));
inOrder.verify(observer, times(1)).onCompleted();
inOrder.verifyNoMoreInteractions();
}
/**
* Can receive timeout if subscribe never receives an onError/onCompleted ... which reveals a race condition.
*/
@Test(timeout = 10000)
public void testSubscribeCompletionRaceCondition() {
/*
* With non-threadsafe code this fails most of the time on my dev laptop and is non-deterministic enough
* to act as a unit test to the race conditions.
*
* With the synchronization code in place I can not get this to fail on my laptop.
*/
for (int i = 0; i < 50; i++) {
final AsyncSubject<String> subject = AsyncSubject.create();
final AtomicReference<String> value1 = new AtomicReference<String>();
subject.subscribe(new Action1<String>() {
@Override
public void call(String t1) {
try {
// simulate a slow observer
Thread.sleep(50);
} catch (InterruptedException e) {
e.printStackTrace();
}
value1.set(t1);
}
});
Thread t1 = new Thread(new Runnable() {
@Override
public void run() {
subject.onNext("value");
subject.onCompleted();
}
});
SubjectObserverThread t2 = new SubjectObserverThread(subject);
SubjectObserverThread t3 = new SubjectObserverThread(subject);
SubjectObserverThread t4 = new SubjectObserverThread(subject);
SubjectObserverThread t5 = new SubjectObserverThread(subject);
t2.start();
t3.start();
t1.start();
t4.start();
t5.start();
try {
t1.join();
t2.join();
t3.join();
t4.join();
t5.join();
} catch (InterruptedException e) {
throw new RuntimeException(e);
}
assertEquals("value", value1.get());
assertEquals("value", t2.value.get());
assertEquals("value", t3.value.get());
assertEquals("value", t4.value.get());
assertEquals("value", t5.value.get());
}
}
private static class SubjectObserverThread extends Thread {
private final AsyncSubject<String> subject;
private final AtomicReference<String> value = new AtomicReference<String>();
public SubjectObserverThread(AsyncSubject<String> subject) {
this.subject = subject;
}
@Override
public void run() {
try {
// a timeout exception will happen if we don't get a terminal state
String v = subject.timeout(2000, TimeUnit.MILLISECONDS).toBlocking().single();
value.set(v);
} catch (Exception e) {
e.printStackTrace();
}
}
}
@Test
public void testOnErrorThrowsDoesntPreventDelivery() {
AsyncSubject<String> ps = AsyncSubject.create();
ps.subscribe();
TestSubscriber<String> ts = new TestSubscriber<String>();
ps.subscribe(ts);
try {
ps.onError(new RuntimeException("an exception"));
fail("expect OnErrorNotImplementedException");
} catch (OnErrorNotImplementedException e) {
// ignore
}
// even though the onError above throws we should still receive it on the other subscriber
assertEquals(1, ts.getOnErrorEvents().size());
}
/**
* This one has multiple failures so should get a CompositeException
*/
@Test
public void testOnErrorThrowsDoesntPreventDelivery2() {
AsyncSubject<String> ps = AsyncSubject.create();
ps.subscribe();
ps.subscribe();
TestSubscriber<String> ts = new TestSubscriber<String>();
ps.subscribe(ts);
ps.subscribe();
ps.subscribe();
ps.subscribe();
try {
ps.onError(new RuntimeException("an exception"));
fail("expect OnErrorNotImplementedException");
} catch (CompositeException e) {
// we should have 5 of them
assertEquals(5, e.getExceptions().size());
}
// even though the onError above throws we should still receive it on the other subscriber
assertEquals(1, ts.getOnErrorEvents().size());
}
@Test
public void testCurrentStateMethodsNormal() {
AsyncSubject<Object> as = AsyncSubject.create();
assertFalse(as.hasValue());
assertFalse(as.hasThrowable());
assertFalse(as.hasCompleted());
assertNull(as.getValue());
assertNull(as.getThrowable());
as.onNext(1);
assertTrue(as.hasValue());
assertFalse(as.hasThrowable());
assertFalse(as.hasCompleted());
assertEquals(1, as.getValue());
assertNull(as.getThrowable());
as.onCompleted();
assertTrue(as.hasValue());
assertFalse(as.hasThrowable());
assertTrue(as.hasCompleted());
assertEquals(1, as.getValue());
assertNull(as.getThrowable());
}
@Test
public void testCurrentStateMethodsEmpty() {
AsyncSubject<Object> as = AsyncSubject.create();
assertFalse(as.hasValue());
assertFalse(as.hasThrowable());
assertFalse(as.hasCompleted());
assertNull(as.getValue());
assertNull(as.getThrowable());
as.onCompleted();
assertFalse(as.hasValue());
assertFalse(as.hasThrowable());
assertTrue(as.hasCompleted());
assertNull(as.getValue());
assertNull(as.getThrowable());
}
@Test
public void testCurrentStateMethodsError() {
AsyncSubject<Object> as = AsyncSubject.create();
assertFalse(as.hasValue());
assertFalse(as.hasThrowable());
assertFalse(as.hasCompleted());
assertNull(as.getValue());
assertNull(as.getThrowable());
as.onError(new TestException());
assertFalse(as.hasValue());
assertTrue(as.hasThrowable());
assertFalse(as.hasCompleted());
assertNull(as.getValue());
assertTrue(as.getThrowable() instanceof TestException);
}
}