/**
* 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.internal.operators.observable;
import static org.junit.Assert.*;
import static org.mockito.ArgumentMatchers.any;
import static org.mockito.Mockito.*;
import java.io.IOException;
import java.util.concurrent.atomic.AtomicReference;
import org.junit.*;
import org.mockito.Mockito;
import org.reactivestreams.Subscription;
import io.reactivex.*;
import io.reactivex.disposables.*;
import io.reactivex.functions.Function;
import io.reactivex.internal.functions.Functions;
import io.reactivex.observers.*;
import io.reactivex.schedulers.Schedulers;
public class ObservableOnErrorResumeNextViaFunctionTest {
@Test
public void testResumeNextWithSynchronousExecution() {
final AtomicReference<Throwable> receivedException = new AtomicReference<Throwable>();
Observable<String> w = Observable.unsafeCreate(new ObservableSource<String>() {
@Override
public void subscribe(Observer<? super String> observer) {
observer.onSubscribe(Disposables.empty());
observer.onNext("one");
observer.onError(new Throwable("injected failure"));
observer.onNext("two");
observer.onNext("three");
}
});
Function<Throwable, Observable<String>> resume = new Function<Throwable, Observable<String>>() {
@Override
public Observable<String> apply(Throwable t1) {
receivedException.set(t1);
return Observable.just("twoResume", "threeResume");
}
};
Observable<String> observable = w.onErrorResumeNext(resume);
Observer<String> observer = TestHelper.mockObserver();
observable.subscribe(observer);
verify(observer, Mockito.never()).onError(any(Throwable.class));
verify(observer, times(1)).onComplete();
verify(observer, times(1)).onNext("one");
verify(observer, Mockito.never()).onNext("two");
verify(observer, Mockito.never()).onNext("three");
verify(observer, times(1)).onNext("twoResume");
verify(observer, times(1)).onNext("threeResume");
assertNotNull(receivedException.get());
}
@Test
public void testResumeNextWithAsyncExecution() {
final AtomicReference<Throwable> receivedException = new AtomicReference<Throwable>();
Subscription s = mock(Subscription.class);
TestObservable w = new TestObservable(s, "one");
Function<Throwable, Observable<String>> resume = new Function<Throwable, Observable<String>>() {
@Override
public Observable<String> apply(Throwable t1) {
receivedException.set(t1);
return Observable.just("twoResume", "threeResume");
}
};
Observable<String> o = Observable.unsafeCreate(w).onErrorResumeNext(resume);
Observer<String> observer = TestHelper.mockObserver();
o.subscribe(observer);
try {
w.t.join();
} catch (InterruptedException e) {
fail(e.getMessage());
}
verify(observer, Mockito.never()).onError(any(Throwable.class));
verify(observer, times(1)).onComplete();
verify(observer, times(1)).onNext("one");
verify(observer, Mockito.never()).onNext("two");
verify(observer, Mockito.never()).onNext("three");
verify(observer, times(1)).onNext("twoResume");
verify(observer, times(1)).onNext("threeResume");
assertNotNull(receivedException.get());
}
/**
* Test that when a function throws an exception this is propagated through onError.
*/
@Test
public void testFunctionThrowsError() {
Subscription s = mock(Subscription.class);
TestObservable w = new TestObservable(s, "one");
Function<Throwable, Observable<String>> resume = new Function<Throwable, Observable<String>>() {
@Override
public Observable<String> apply(Throwable t1) {
throw new RuntimeException("exception from function");
}
};
Observable<String> o = Observable.unsafeCreate(w).onErrorResumeNext(resume);
@SuppressWarnings("unchecked")
DefaultObserver<String> observer = mock(DefaultObserver.class);
o.subscribe(observer);
try {
w.t.join();
} catch (InterruptedException e) {
fail(e.getMessage());
}
// we should get the "one" value before the error
verify(observer, times(1)).onNext("one");
// we should have received an onError call on the Observer since the resume function threw an exception
verify(observer, times(1)).onError(any(Throwable.class));
verify(observer, times(0)).onComplete();
}
/**
* Test that we receive the onError if an exception is thrown from an operator that
* does not have manual try/catch handling like map does.
*/
@Test
@Ignore("Failed operator may leave the child Observer in an inconsistent state which prevents further error delivery.")
public void testOnErrorResumeReceivesErrorFromPreviousNonProtectedOperator() {
TestObserver<String> ts = new TestObserver<String>();
Observable.just(1).lift(new ObservableOperator<String, Integer>() {
@Override
public Observer<? super Integer> apply(Observer<? super String> t1) {
throw new RuntimeException("failed");
}
}).onErrorResumeNext(new Function<Throwable, Observable<String>>() {
@Override
public Observable<String> apply(Throwable t1) {
if (t1.getMessage().equals("failed")) {
return Observable.just("success");
} else {
return Observable.error(t1);
}
}
}).subscribe(ts);
ts.assertTerminated();
System.out.println(ts.values());
ts.assertValue("success");
}
/**
* Test that we receive the onError if an exception is thrown from an operator that
* does not have manual try/catch handling like map does.
*/
@Test
@Ignore("A crashing operator may leave the downstream in an inconsistent state and not suitable for event delivery")
public void testOnErrorResumeReceivesErrorFromPreviousNonProtectedOperatorOnNext() {
TestObserver<String> ts = new TestObserver<String>();
Observable.just(1).lift(new ObservableOperator<String, Integer>() {
@Override
public Observer<? super Integer> apply(final Observer<? super String> t1) {
return new Observer<Integer>() {
@Override
public void onSubscribe(Disposable s) {
t1.onSubscribe(s);
}
@Override
public void onComplete() {
throw new RuntimeException("failed");
}
@Override
public void onError(Throwable e) {
throw new RuntimeException("failed");
}
@Override
public void onNext(Integer t) {
throw new RuntimeException("failed");
}
};
}
}).onErrorResumeNext(new Function<Throwable, Observable<String>>() {
@Override
public Observable<String> apply(Throwable t1) {
if (t1.getMessage().equals("failed")) {
return Observable.just("success");
} else {
return Observable.error(t1);
}
}
}).subscribe(ts);
ts.assertTerminated();
System.out.println(ts.values());
ts.assertValue("success");
}
@Test
public void testMapResumeAsyncNext() {
// Trigger multiple failures
Observable<String> w = Observable.just("one", "fail", "two", "three", "fail");
// Introduce map function that fails intermittently (Map does not prevent this when the Observer is a
// rx.operator incl onErrorResumeNextViaObservable)
w = w.map(new Function<String, String>() {
@Override
public String apply(String s) {
if ("fail".equals(s)) {
throw new RuntimeException("Forced Failure");
}
System.out.println("BadMapper:" + s);
return s;
}
});
Observable<String> o = w.onErrorResumeNext(new Function<Throwable, Observable<String>>() {
@Override
public Observable<String> apply(Throwable t1) {
return Observable.just("twoResume", "threeResume").subscribeOn(Schedulers.computation());
}
});
@SuppressWarnings("unchecked")
DefaultObserver<String> observer = mock(DefaultObserver.class);
TestObserver<String> ts = new TestObserver<String>(observer);
o.subscribe(ts);
ts.awaitTerminalEvent();
verify(observer, Mockito.never()).onError(any(Throwable.class));
verify(observer, times(1)).onComplete();
verify(observer, times(1)).onNext("one");
verify(observer, Mockito.never()).onNext("two");
verify(observer, Mockito.never()).onNext("three");
verify(observer, times(1)).onNext("twoResume");
verify(observer, times(1)).onNext("threeResume");
}
static class TestObservable implements ObservableSource<String> {
final String[] values;
Thread t;
TestObservable(Subscription s, String... values) {
this.values = values;
}
@Override
public void subscribe(final Observer<? super String> observer) {
System.out.println("TestObservable subscribed to ...");
observer.onSubscribe(Disposables.empty());
t = new Thread(new Runnable() {
@Override
public void run() {
try {
System.out.println("running TestObservable thread");
for (String s : values) {
System.out.println("TestObservable onNext: " + s);
observer.onNext(s);
}
throw new RuntimeException("Forced Failure");
} catch (Throwable e) {
observer.onError(e);
}
}
});
System.out.println("starting TestObservable thread");
t.start();
System.out.println("done starting TestObservable thread");
}
}
@Test
public void testBackpressure() {
TestObserver<Integer> ts = new TestObserver<Integer>();
Observable.range(0, 100000)
.onErrorResumeNext(new Function<Throwable, Observable<Integer>>() {
@Override
public Observable<Integer> apply(Throwable t1) {
return Observable.just(1);
}
})
.observeOn(Schedulers.computation())
.map(new Function<Integer, Integer>() {
int c;
@Override
public Integer apply(Integer t1) {
if (c++ <= 1) {
// slow
try {
Thread.sleep(500);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
return t1;
}
})
.subscribe(ts);
ts.awaitTerminalEvent();
ts.assertNoErrors();
}
@Test
public void badOtherSource() {
TestHelper.checkBadSourceObservable(new Function<Observable<Integer>, Object>() {
@Override
public Object apply(Observable<Integer> o) throws Exception {
return Observable.error(new IOException())
.onErrorResumeNext(Functions.justFunction(o));
}
}, false, 1, 1, 1);
}
}