code: /*
   * 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.rxjava3.internal.operators.flowable;
  
  import static org.junit.Assert.fail;
  import static org.mockito.ArgumentMatchers.any;
  import static org.mockito.Mockito.*;
  
  import java.util.concurrent.TimeUnit;
  
  import org.junit.Test;
  import org.mockito.Mockito;
  import org.reactivestreams.*;
  
  import io.reactivex.rxjava3.core.*;
  import io.reactivex.rxjava3.exceptions.TestException;
  import io.reactivex.rxjava3.functions.Function;
  import io.reactivex.rxjava3.processors.PublishProcessor;
  import io.reactivex.rxjava3.schedulers.Schedulers;
  import io.reactivex.rxjava3.subscribers.TestSubscriber;
  import io.reactivex.rxjava3.testsupport.TestHelper;
  
  public class FlowableOnErrorResumeNextViaFlowableTest extends RxJavaTest {
  
      @Test
      public void resumeNext() {
          Subscription s = mock(Subscription.class);
          // Trigger failure on second element
          TestObservable f = new TestObservable(s, "one", "fail", "two", "three");
          Flowable<String> w = Flowable.unsafeCreate(f);
          Flowable<String> resume = Flowable.just("twoResume", "threeResume");
          Flowable<String> flowable = w.onErrorResumeWith(resume);
  
          Subscriber<String> subscriber = TestHelper.mockSubscriber();
          flowable.subscribe(subscriber);
  
          try {
              f.t.join();
          } catch (InterruptedException e) {
              fail(e.getMessage());
          }
  
          verify(subscriber, Mockito.never()).onError(any(Throwable.class));
          verify(subscriber, times(1)).onComplete();
          verify(subscriber, times(1)).onNext("one");
          verify(subscriber, Mockito.never()).onNext("two");
          verify(subscriber, Mockito.never()).onNext("three");
          verify(subscriber, times(1)).onNext("twoResume");
          verify(subscriber, times(1)).onNext("threeResume");
      }
  
      @Test
      public void mapResumeAsyncNext() {
          Subscription sr = mock(Subscription.class);
          // Trigger multiple failures
          Flowable<String> w = Flowable.just("one", "fail", "two", "three", "fail");
          // Resume Observable is async
          TestObservable f = new TestObservable(sr, "twoResume", "threeResume");
          Flowable<String> resume = Flowable.unsafeCreate(f);
  
          // 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;
              }
          });
  
          Flowable<String> flowable = w.onErrorResumeWith(resume);
  
          Subscriber<String> subscriber = TestHelper.mockSubscriber();
  
          flowable.subscribe(subscriber);
  
          try {
              f.t.join();
          } catch (InterruptedException e) {
              fail(e.getMessage());
          }
  
          verify(subscriber, Mockito.never()).onError(any(Throwable.class));
          verify(subscriber, times(1)).onComplete();
          verify(subscriber, times(1)).onNext("one");
          verify(subscriber, Mockito.never()).onNext("two");
          verify(subscriber, Mockito.never()).onNext("three");
          verify(subscriber, times(1)).onNext("twoResume");
          verify(subscriber, times(1)).onNext("threeResume");
      }
  
      static final class TestObservable implements Publisher<String> {
  
          final Subscription upstream;
          final String[] values;
          Thread t;
  
          TestObservable(Subscription s, String... values) {
              this.upstream = s;
              this.values = values;
          }
  
          @Override
          public void subscribe(final Subscriber<? super String> subscriber) {
              System.out.println("TestObservable subscribed to ...");
              subscriber.onSubscribe(upstream);
              t = new Thread(new Runnable() {
  
                  @Override
                  public void run() {
                      try {
                          System.out.println("running TestObservable thread");
                          for (String s : values) {
                              if ("fail".equals(s)) {
                                  throw new RuntimeException("Forced Failure");
                              }
                              System.out.println("TestObservable onNext: " + s);
                              subscriber.onNext(s);
                          }
                          System.out.println("TestObservable onComplete");
                          subscriber.onComplete();
                      } catch (Throwable e) {
                          System.out.println("TestObservable onError: " + e);
                          subscriber.onError(e);
                      }
                  }
  
              });
              System.out.println("starting TestObservable thread");
              t.start();
              System.out.println("done starting TestObservable thread");
          }
      }
  
      @Test
      public void backpressure() {
          TestSubscriber<Integer> ts = new TestSubscriber<>();
          Flowable.range(0, 100000)
                  .onErrorResumeWith(Flowable.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.awaitDone(5, TimeUnit.SECONDS);
          ts.assertNoErrors();
      }
  
      @Test
      public void normalBackpressure() {
          TestSubscriber<Integer> ts = TestSubscriber.create(0);
  
          PublishProcessor<Integer> pp = PublishProcessor.create();
  
          pp.onErrorResumeWith(Flowable.range(3, 2)).subscribe(ts);
  
          ts.request(2);
  
          pp.onNext(1);
          pp.onNext(2);
          pp.onError(new TestException("Forced failure"));
  
          ts.assertValues(1, 2);
          ts.assertNoErrors();
          ts.assertNotComplete();
  
          ts.request(2);
  
          ts.assertValues(1, 2, 3, 4);
          ts.assertNoErrors();
          ts.assertComplete();
      }
  
  }
  