/**
* 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.subscribers;
import java.util.concurrent.atomic.*;
import org.reactivestreams.*;
import io.reactivex.FlowableSubscriber;
import io.reactivex.disposables.Disposable;
import io.reactivex.functions.Consumer;
import io.reactivex.internal.fuseable.QueueSubscription;
import io.reactivex.internal.subscriptions.SubscriptionHelper;
import io.reactivex.internal.util.ExceptionHelper;
import io.reactivex.observers.BaseTestConsumer;
/**
* A subscriber that records events and allows making assertions about them.
*
* <p>You can override the onSubscribe, onNext, onError, onComplete, request and
* cancel methods but not the others (this is by design).
*
* <p>The TestSubscriber implements Disposable for convenience where dispose calls cancel.
*
* <p>When calling the default request method, you are requesting on behalf of the
* wrapped actual subscriber.
*
* @param <T> the value type
*/
public class TestSubscriber<T>
extends BaseTestConsumer<T, TestSubscriber<T>>
implements FlowableSubscriber<T>, Subscription, Disposable {
/** The actual subscriber to forward events to. */
private final Subscriber<? super T> actual;
/** Makes sure the incoming Subscriptions get cancelled immediately. */
private volatile boolean cancelled;
/** Holds the current subscription if any. */
private final AtomicReference<Subscription> subscription;
/** Holds the requested amount until a subscription arrives. */
private final AtomicLong missedRequested;
private QueueSubscription<T> qs;
/**
* Creates a TestSubscriber with Long.MAX_VALUE initial request.
* @param <T> the value type
* @return the new TestSubscriber instance.
*/
public static <T> TestSubscriber<T> create() {
return new TestSubscriber<T>();
}
/**
* Creates a TestSubscriber with the given initial request.
* @param <T> the value type
* @param initialRequested the initial requested amount
* @return the new TestSubscriber instance.
*/
public static <T> TestSubscriber<T> create(long initialRequested) {
return new TestSubscriber<T>(initialRequested);
}
/**
* Constructs a forwarding TestSubscriber.
* @param <T> the value type received
* @param delegate the actual Subscriber to forward events to
* @return the new TestObserver instance
*/
public static <T> TestSubscriber<T> create(Subscriber<? super T> delegate) {
return new TestSubscriber<T>(delegate);
}
/**
* Constructs a non-forwarding TestSubscriber with an initial request value of Long.MAX_VALUE.
*/
public TestSubscriber() {
this(EmptySubscriber.INSTANCE, Long.MAX_VALUE);
}
/**
* Constructs a non-forwarding TestSubscriber with the specified initial request value.
* <p>The TestSubscriber doesn't validate the initialRequest value so one can
* test sources with invalid values as well.
* @param initialRequest the initial request value
*/
public TestSubscriber(long initialRequest) {
this(EmptySubscriber.INSTANCE, initialRequest);
}
/**
* Constructs a forwarding TestSubscriber but leaves the requesting to the wrapped subscriber.
* @param actual the actual Subscriber to forward events to
*/
public TestSubscriber(Subscriber<? super T> actual) {
this(actual, Long.MAX_VALUE);
}
/**
* Constructs a forwarding TestSubscriber with the specified initial request value.
* <p>The TestSubscriber doesn't validate the initialRequest value so one can
* test sources with invalid values as well.
* @param actual the actual Subscriber to forward events to
* @param initialRequest the initial request value
*/
public TestSubscriber(Subscriber<? super T> actual, long initialRequest) {
super();
if (initialRequest < 0) {
throw new IllegalArgumentException("Negative initial request not allowed");
}
this.actual = actual;
this.subscription = new AtomicReference<Subscription>();
this.missedRequested = new AtomicLong(initialRequest);
}
@SuppressWarnings("unchecked")
@Override
public void onSubscribe(Subscription s) {
lastThread = Thread.currentThread();
if (s == null) {
errors.add(new NullPointerException("onSubscribe received a null Subscription"));
return;
}
if (!subscription.compareAndSet(null, s)) {
s.cancel();
if (subscription.get() != SubscriptionHelper.CANCELLED) {
errors.add(new IllegalStateException("onSubscribe received multiple subscriptions: " + s));
}
return;
}
if (initialFusionMode != 0) {
if (s instanceof QueueSubscription) {
qs = (QueueSubscription<T>)s;
int m = qs.requestFusion(initialFusionMode);
establishedFusionMode = m;
if (m == QueueSubscription.SYNC) {
checkSubscriptionOnce = true;
lastThread = Thread.currentThread();
try {
T t;
while ((t = qs.poll()) != null) {
values.add(t);
}
completions++;
} catch (Throwable ex) {
// Exceptions.throwIfFatal(e); TODO add fatal exceptions?
errors.add(ex);
}
return;
}
}
}
actual.onSubscribe(s);
long mr = missedRequested.getAndSet(0L);
if (mr != 0L) {
s.request(mr);
}
onStart();
}
/**
* Called after the onSubscribe is called and handled.
*/
protected void onStart() {
}
@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 == QueueSubscription.ASYNC) {
try {
while ((t = qs.poll()) != null) {
values.add(t);
}
} catch (Throwable ex) {
// Exceptions.throwIfFatal(e); TODO add fatal exceptions?
errors.add(ex);
qs.cancel();
}
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 NullPointerException("onSubscribe not called in proper order"));
}
}
try {
lastThread = Thread.currentThread();
errors.add(t);
if (t == null) {
errors.add(new IllegalStateException("onError received a null Throwable"));
}
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();
}
}
@Override
public final void request(long n) {
SubscriptionHelper.deferredRequest(subscription, missedRequested, n);
}
@Override
public final void cancel() {
if (!cancelled) {
cancelled = true;
SubscriptionHelper.cancel(subscription);
}
}
/**
* Returns true if this TestSubscriber has been cancelled.
* @return true if this TestSubscriber has been cancelled
*/
public final boolean isCancelled() {
return cancelled;
}
@Override
public final void dispose() {
cancel();
}
@Override
public final boolean isDisposed() {
return cancelled;
}
// state retrieval methods
/**
* Returns true if this TestSubscriber received a subscription.
* @return true if this TestSubscriber received a subscription
*/
public final boolean hasSubscription() {
return subscription.get() != null;
}
// assertion methods
/**
* Assert that the onSubscribe method was called exactly once.
* @return this
*/
@Override
public final TestSubscriber<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 TestSubscriber<T> assertNotSubscribed() {
if (subscription.get() != null) {
throw fail("Subscribed!");
} else
if (!errors.isEmpty()) {
throw fail("Not subscribed but errors found");
}
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 SubscriberFusion to work with such tests.
* @param mode the mode to establish, see the {@link QueueSubscription} constants
* @return this
*/
final TestSubscriber<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 SubscriberFusion to work with such tests.
* @param mode the expected mode
* @return this
*/
final TestSubscriber<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 QueueSubscription.NONE : return "NONE";
case QueueSubscription.SYNC : return "SYNC";
case QueueSubscription.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 SubscriberFusion to work with such tests.
* @return this
*/
final TestSubscriber<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 SubscriberFusion to work with such tests.
* @return this
*/
final TestSubscriber<T> assertNotFuseable() {
if (qs != null) {
throw new AssertionError("Upstream is fuseable.");
}
return this;
}
/**
* Run a check consumer with this TestSubscriber instance.
* @param check the check consumer to run
* @return this
*/
public final TestSubscriber<T> assertOf(Consumer<? super TestSubscriber<T>> check) {
try {
check.accept(this);
} catch (Throwable ex) {
throw ExceptionHelper.wrapOrThrow(ex);
}
return this;
}
/**
* Calls {@link #request(long)} and returns this.
* <p>History: 2.0.1 - experimental
* @param n the request amount
* @return this
* @since 2.1
*/
public final TestSubscriber<T> requestMore(long n) {
request(n);
return this;
}
/**
* A subscriber that ignores all events and does not report errors.
*/
enum EmptySubscriber implements FlowableSubscriber<Object> {
INSTANCE;
@Override
public void onSubscribe(Subscription s) {
}
@Override
public void onNext(Object t) {
}
@Override
public void onError(Throwable t) {
}
@Override
public void onComplete() {
}
}
}