/**
* Copyright (c) 2016-present, RxJava Contributors.
*
* 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 io.reactivex.observers;
import java.util.concurrent.atomic.AtomicReference;
import io.reactivex.*;
import io.reactivex.disposables.Disposable;
import io.reactivex.functions.Consumer;
import io.reactivex.internal.disposables.DisposableHelper;
import io.reactivex.internal.fuseable.QueueDisposable;
import io.reactivex.internal.util.*;
/**
* An Observer that records events and allows making assertions about them.
*
* <p>You can override the onSubscribe, onNext, onError, onComplete, onSuccess and
* cancel methods but not the others (this is by design).
*
* <p>The TestObserver implements Disposable for convenience where dispose calls cancel.
*
* @param <T> the value type
*/
public class TestObserver<T>
extends BaseTestConsumer<T, TestObserver<T>>
implements Observer<T>, Disposable, MaybeObserver<T>, SingleObserver<T>, CompletableObserver {
/** The actual observer to forward events to. */
private final Observer<? super T> actual;
/** Holds the current subscription if any. */
private final AtomicReference<Disposable> subscription = new AtomicReference<Disposable>();
private QueueDisposable<T> qs;
/**
* Constructs a non-forwarding TestObserver.
* @param <T> the value type received
* @return the new TestObserver instance
*/
public static <T> TestObserver<T> create() {
return new TestObserver<T>();
}
/**
* Constructs a forwarding TestObserver.
* @param <T> the value type received
* @param delegate the actual Observer to forward events to
* @return the new TestObserver instance
*/
public static <T> TestObserver<T> create(Observer<? super T> delegate) {
return new TestObserver<T>(delegate);
}
/**
* Constructs a non-forwarding TestObserver.
*/
public TestObserver() {
this(EmptyObserver.INSTANCE);
}
/**
* Constructs a forwarding TestObserver.
* @param actual the actual Observer to forward events to
*/
public TestObserver(Observer<? super T> actual) {
this.actual = actual;
}
@SuppressWarnings("unchecked")
@Override
public void onSubscribe(Disposable s) {
lastThread = Thread.currentThread();
if (s == null) {
errors.add(new NullPointerException("onSubscribe received a null Subscription"));
return;
}
if (!subscription.compareAndSet(null, s)) {
s.dispose();
if (subscription.get() != DisposableHelper.DISPOSED) {
errors.add(new IllegalStateException("onSubscribe received multiple subscriptions: " + s));
}
return;
}
if (initialFusionMode != 0) {
if (s instanceof QueueDisposable) {
qs = (QueueDisposable<T>)s;
int m = qs.requestFusion(initialFusionMode);
establishedFusionMode = m;
if (m == QueueDisposable.SYNC) {
checkSubscriptionOnce = true;
lastThread = Thread.currentThread();
try {
T t;
while ((t = qs.poll()) != null) {
values.add(t);
}
completions++;
subscription.lazySet(DisposableHelper.DISPOSED);
} catch (Throwable ex) {
// Exceptions.throwIfFatal(e); TODO add fatal exceptions?
errors.add(ex);
}
return;
}
}
}
actual.onSubscribe(s);
}
@Override
public void onNext(T t) {
if (!checkSubscriptionOnce) {
checkSubscriptionOnce = true;
if (subscription.get() == null) {
errors.add(new IllegalStateException("onSubscribe not called in proper order"));
}
}
lastThread = Thread.currentThread();
if (establishedFusionMode == QueueDisposable.ASYNC) {
try {
while ((t = qs.poll()) != null) {
values.add(t);
}
} catch (Throwable ex) {
// Exceptions.throwIfFatal(e); TODO add fatal exceptions?
errors.add(ex);
qs.dispose();
}
return;
}
values.add(t);
if (t == null) {
errors.add(new NullPointerException("onNext received a null value"));
}
actual.onNext(t);
}
@Override
public void onError(Throwable t) {
if (!checkSubscriptionOnce) {
checkSubscriptionOnce = true;
if (subscription.get() == null) {
errors.add(new IllegalStateException("onSubscribe not called in proper order"));
}
}
try {
lastThread = Thread.currentThread();
if (t == null) {
errors.add(new NullPointerException("onError received a null Throwable"));
} else {
errors.add(t);
}
actual.onError(t);
} finally {
done.countDown();
}
}
@Override
public void onComplete() {
if (!checkSubscriptionOnce) {
checkSubscriptionOnce = true;
if (subscription.get() == null) {
errors.add(new IllegalStateException("onSubscribe not called in proper order"));
}
}
try {
lastThread = Thread.currentThread();
completions++;
actual.onComplete();
} finally {
done.countDown();
}
}
/**
* Returns true if this TestObserver has been cancelled.
* @return true if this TestObserver has been cancelled
*/
public final boolean isCancelled() {
return isDisposed();
}
/**
* Cancels the TestObserver (before or after the subscription happened).
* <p>This operation is thread-safe.
* <p>This method is provided as a convenience when converting Flowable tests that cancel.
*/
public final void cancel() {
dispose();
}
@Override
public final void dispose() {
DisposableHelper.dispose(subscription);
}
@Override
public final boolean isDisposed() {
return DisposableHelper.isDisposed(subscription.get());
}
// state retrieval methods
/**
* Returns true if this TestObserver received a subscription.
* @return true if this TestObserver received a subscription
*/
public final boolean hasSubscription() {
return subscription.get() != null;
}
/**
* Assert that the onSubscribe method was called exactly once.
* @return this;
*/
@Override
public final TestObserver<T> assertSubscribed() {
if (subscription.get() == null) {
throw fail("Not subscribed!");
}
return this;
}
/**
* Assert that the onSubscribe method hasn't been called at all.
* @return this;
*/
@Override
public final TestObserver<T> assertNotSubscribed() {
if (subscription.get() != null) {
throw fail("Subscribed!");
} else
if (!errors.isEmpty()) {
throw fail("Not subscribed but errors found");
}
return this;
}
/**
* Run a check consumer with this TestObserver instance.
* @param check the check consumer to run
* @return this
*/
public final TestObserver<T> assertOf(Consumer<? super TestObserver<T>> check) {
try {
check.accept(this);
} catch (Throwable ex) {
throw ExceptionHelper.wrapOrThrow(ex);
}
return this;
}
/**
* Sets the initial fusion mode if the upstream supports fusion.
* <p>Package-private: avoid leaking the now internal fusion properties into the public API.
* Use ObserverFusion to work with such tests.
* @param mode the mode to establish, see the {@link QueueDisposable} constants
* @return this
*/
final TestObserver<T> setInitialFusionMode(int mode) {
this.initialFusionMode = mode;
return this;
}
/**
* Asserts that the given fusion mode has been established
* <p>Package-private: avoid leaking the now internal fusion properties into the public API.
* Use ObserverFusion to work with such tests.
* @param mode the expected mode
* @return this
*/
final TestObserver<T> assertFusionMode(int mode) {
int m = establishedFusionMode;
if (m != mode) {
if (qs != null) {
throw new AssertionError("Fusion mode different. Expected: " + fusionModeToString(mode)
+ ", actual: " + fusionModeToString(m));
} else {
throw fail("Upstream is not fuseable");
}
}
return this;
}
static String fusionModeToString(int mode) {
switch (mode) {
case QueueDisposable.NONE : return "NONE";
case QueueDisposable.SYNC : return "SYNC";
case QueueDisposable.ASYNC : return "ASYNC";
default: return "Unknown(" + mode + ")";
}
}
/**
* Assert that the upstream is a fuseable source.
* <p>Package-private: avoid leaking the now internal fusion properties into the public API.
* Use ObserverFusion to work with such tests.
* @return this
*/
final TestObserver<T> assertFuseable() {
if (qs == null) {
throw new AssertionError("Upstream is not fuseable.");
}
return this;
}
/**
* Assert that the upstream is not a fuseable source.
* <p>Package-private: avoid leaking the now internal fusion properties into the public API.
* Use ObserverFusion to work with such tests.
* @return this
*/
final TestObserver<T> assertNotFuseable() {
if (qs != null) {
throw new AssertionError("Upstream is fuseable.");
}
return this;
}
@Override
public void onSuccess(T value) {
onNext(value);
onComplete();
}
/**
* An observer that ignores all events and does not report errors.
*/
enum EmptyObserver implements Observer<Object> {
INSTANCE;
@Override
public void onSubscribe(Disposable d) {
}
@Override
public void onNext(Object t) {
}
@Override
public void onError(Throwable t) {
}
@Override
public void onComplete() {
}
}
}