/**
* 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.observers;
import java.util.List;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.TimeUnit;
import rx.Notification;
import rx.Observer;
import rx.Subscriber;
/**
* Subscriber usable for unit testing to perform assertions, inspect received events, or wrap a mocked
* Subscriber.
*/
public class TestSubscriber<T> extends Subscriber<T> {
private final TestObserver<T> testObserver;
private final CountDownLatch latch = new CountDownLatch(1);
private volatile Thread lastSeenThread;
public TestSubscriber(Subscriber<T> delegate) {
this.testObserver = new TestObserver<T>(delegate);
}
public TestSubscriber(Observer<T> delegate) {
this.testObserver = new TestObserver<T>(delegate);
}
public TestSubscriber() {
this.testObserver = new TestObserver<T>(new Observer<T>() {
@Override
public void onCompleted() {
// do nothing
}
@Override
public void onError(Throwable e) {
// do nothing
}
@Override
public void onNext(T t) {
// do nothing
}
});
}
@Override
public void onCompleted() {
try {
lastSeenThread = Thread.currentThread();
testObserver.onCompleted();
} finally {
latch.countDown();
}
}
/**
* Get the {@link Notification}s representing each time this Subscriber was notified of sequence completion
* via {@link #onCompleted}, as a {@link List}.
*
* @return a list of Notifications representing calls to this Subscriber's {@link #onCompleted} method
*/
public List<Notification<T>> getOnCompletedEvents() {
return testObserver.getOnCompletedEvents();
}
@Override
public void onError(Throwable e) {
try {
lastSeenThread = Thread.currentThread();
testObserver.onError(e);
} finally {
latch.countDown();
}
}
/**
* Get the {@link Throwable}s this Subscriber was notified of via {@link #onError} as a {@link List}.
*
* @return a list of the Throwables that were passed to this Subscriber's {@link #onError} method
*/
public List<Throwable> getOnErrorEvents() {
return testObserver.getOnErrorEvents();
}
@Override
public void onNext(T t) {
lastSeenThread = Thread.currentThread();
testObserver.onNext(t);
}
/**
* Allow calling the protected {@link #request(long)} from unit tests.
* @param n
*/
public void requestMore(long n) {
request(n);
}
/**
* Get the sequence of items observed by this Subscriber, as an ordered {@link List}.
*
* @return a list of items observed by this Subscriber, in the order in which they were observed
*/
public List<T> getOnNextEvents() {
return testObserver.getOnNextEvents();
}
/**
* Assert that a particular sequence of items was received by this Subscriber in order.
*
* @param items
* the sequence of items expected to have been observed
* @throws AssertionError
* if the sequence of items observed does not exactly match {@code items}
*/
public void assertReceivedOnNext(List<T> items) {
testObserver.assertReceivedOnNext(items);
}
/**
* Assert that a single terminal event occurred, either {@link #onCompleted} or {@link #onError}.
*
* @throws AssertionError
* if not exactly one terminal event notification was received
*/
public void assertTerminalEvent() {
testObserver.assertTerminalEvent();
}
/**
* Assert that this {@code Subscriber} is unsubscribed.
*
* @throws AssertionError
* if this {@code Subscriber} is not unsubscribed
*/
public void assertUnsubscribed() {
if (!isUnsubscribed()) {
throw new AssertionError("Not unsubscribed.");
}
}
/**
* Assert that this {@code Subscriber} has received no {@code onError} notifications.
*
* @throws AssertionError
* if this {@code Subscriber} has received one or more {@code onError} notifications
*/
public void assertNoErrors() {
if (getOnErrorEvents().size() > 0) {
// can't use AssertionError because (message, cause) doesn't exist until Java 7
throw new RuntimeException("Unexpected onError events: " + getOnErrorEvents().size(), getOnErrorEvents().get(0));
// TODO possibly check for Java7+ and then use AssertionError at runtime (since we always compile with 7)
}
}
/**
* Blocks until this Subscriber receives a notification that the Observable is complete (either an
* {@code onCompleted} or {@code onError} notification).
*
* @throws RuntimeException
* if the Subscriber is interrupted before the Observable is able to complete
*/
public void awaitTerminalEvent() {
try {
latch.await();
} catch (InterruptedException e) {
throw new RuntimeException("Interrupted", e);
}
}
/**
* Blocks until this Subscriber receives a notification that the Observable is complete (either an
* {@code onCompleted} or {@code onError} notification), or until a timeout expires.
*
* @param timeout
* the duration of the timeout
* @param unit
* the units in which {@code timeout} is expressed
* @throws RuntimeException
* if the Subscriber is interrupted before the Observable is able to complete
*/
public void awaitTerminalEvent(long timeout, TimeUnit unit) {
try {
latch.await(timeout, unit);
} catch (InterruptedException e) {
throw new RuntimeException("Interrupted", e);
}
}
/**
* Blocks until this Subscriber receives a notification that the Observable is complete (either an
* {@code onCompleted} or {@code onError} notification), or until a timeout expires; if the Subscriber
* is interrupted before either of these events take place, this method unsubscribes the Subscriber from the
* Observable).
*
* @param timeout
* the duration of the timeout
* @param unit
* the units in which {@code timeout} is expressed
*/
public void awaitTerminalEventAndUnsubscribeOnTimeout(long timeout, TimeUnit unit) {
try {
awaitTerminalEvent(timeout, unit);
} catch (RuntimeException e) {
unsubscribe();
}
}
/**
* Returns the last thread that was in use when an item or notification was received by this Subscriber.
*
* @return the {@code Thread} on which this Subscriber last received an item or notification from the
* Observable it is subscribed to
*/
public Thread getLastSeenThread() {
return lastSeenThread;
}
}