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.observable;
  
  import static org.junit.Assert.assertEquals;
  import static org.mockito.ArgumentMatchers.any;
  import static org.mockito.Mockito.*;
  
  import java.io.IOException;
  import java.util.List;
  import java.util.concurrent.atomic.AtomicInteger;
  
  import io.reactivex.rxjava3.disposables.Disposable;
  import org.junit.*;
  
  import io.reactivex.rxjava3.core.*;
  import io.reactivex.rxjava3.exceptions.*;
  import io.reactivex.rxjava3.functions.*;
  import io.reactivex.rxjava3.internal.functions.Functions;
  import io.reactivex.rxjava3.observers.TestObserver;
  import io.reactivex.rxjava3.operators.QueueFuseable;
  import io.reactivex.rxjava3.plugins.RxJavaPlugins;
  import io.reactivex.rxjava3.subjects.UnicastSubject;
  import io.reactivex.rxjava3.testsupport.*;
  
  public class ObservableDoOnEachTest extends RxJavaTest {
  
      Observer<String> subscribedObserver;
      Observer<String> sideEffectObserver;
  
      @Before
      public void before() {
          subscribedObserver = TestHelper.mockObserver();
          sideEffectObserver = TestHelper.mockObserver();
      }
  
      @Test
      public void doOnEach() {
          Observable<String> base = Observable.just("a", "b", "c");
          Observable<String> doOnEach = base.doOnEach(sideEffectObserver);
  
          doOnEach.subscribe(subscribedObserver);
  
          // ensure the leaf Observer is still getting called
          verify(subscribedObserver, never()).onError(any(Throwable.class));
          verify(subscribedObserver, times(1)).onNext("a");
          verify(subscribedObserver, times(1)).onNext("b");
          verify(subscribedObserver, times(1)).onNext("c");
          verify(subscribedObserver, times(1)).onComplete();
  
          // ensure our injected Observer is getting called
          verify(sideEffectObserver, never()).onError(any(Throwable.class));
          verify(sideEffectObserver, times(1)).onNext("a");
          verify(sideEffectObserver, times(1)).onNext("b");
          verify(sideEffectObserver, times(1)).onNext("c");
          verify(sideEffectObserver, times(1)).onComplete();
      }
  
      @Test
      public void doOnEachWithError() {
          Observable<String> base = Observable.just("one", "fail", "two", "three", "fail");
          Observable<String> errs = base.map(new Function<String, String>() {
              @Override
              public String apply(String s) {
                  if ("fail".equals(s)) {
                      throw new RuntimeException("Forced Failure");
                  }
                  return s;
              }
          });
  
          Observable<String> doOnEach = errs.doOnEach(sideEffectObserver);
  
          doOnEach.subscribe(subscribedObserver);
          verify(subscribedObserver, times(1)).onNext("one");
          verify(subscribedObserver, never()).onNext("two");
          verify(subscribedObserver, never()).onNext("three");
          verify(subscribedObserver, never()).onComplete();
          verify(subscribedObserver, times(1)).onError(any(Throwable.class));
  
          verify(sideEffectObserver, times(1)).onNext("one");
          verify(sideEffectObserver, never()).onNext("two");
          verify(sideEffectObserver, never()).onNext("three");
          verify(sideEffectObserver, never()).onComplete();
          verify(sideEffectObserver, times(1)).onError(any(Throwable.class));
      }
  
      @Test
      public void doOnEachWithErrorInCallback() {
          Observable<String> base = Observable.just("one", "two", "fail", "three");
          Observable<String> doOnEach = base.doOnNext(new Consumer<String>() {
              @Override
              public void accept(String s) {
                  if ("fail".equals(s)) {
                      throw new RuntimeException("Forced Failure");
                  }
              }
          });
  
          doOnEach.subscribe(subscribedObserver);
          verify(subscribedObserver, times(1)).onNext("one");
          verify(subscribedObserver, times(1)).onNext("two");
          verify(subscribedObserver, never()).onNext("three");
          verify(subscribedObserver, never()).onComplete();
          verify(subscribedObserver, times(1)).onError(any(Throwable.class));
  
      }
  
      @Test
      public void issue1451Case1() {
          // https://github.com/Netflix/RxJava/issues/1451
          final int expectedCount = 3;
          final AtomicInteger count = new AtomicInteger();
          for (int i = 0; i < expectedCount; i++) {
              Observable
                      .just(Boolean.TRUE, Boolean.FALSE)
                      .takeWhile(new Predicate<Boolean>() {
                          @Override
                          public boolean test(Boolean value) {
                              return value;
                          }
                      })
                      .toList()
                      .doOnSuccess(new Consumer<List<Boolean>>() {
                          @Override
                          public void accept(List<Boolean> booleans) {
                              count.incrementAndGet();
                          }
                      })
                      .subscribe();
          }
          assertEquals(expectedCount, count.get());
      }
  
      @Test
      public void issue1451Case2() {
          // https://github.com/Netflix/RxJava/issues/1451
          final int expectedCount = 3;
          final AtomicInteger count = new AtomicInteger();
          for (int i = 0; i < expectedCount; i++) {
              Observable
                      .just(Boolean.TRUE, Boolean.FALSE, Boolean.FALSE)
                      .takeWhile(new Predicate<Boolean>() {
                          @Override
                          public boolean test(Boolean value) {
                              return value;
                          }
                      })
                      .toList()
                      .doOnSuccess(new Consumer<List<Boolean>>() {
                          @Override
                          public void accept(List<Boolean> booleans) {
                              count.incrementAndGet();
                          }
                      })
                      .subscribe();
          }
          assertEquals(expectedCount, count.get());
      }
  
      // FIXME crashing ObservableSource can't propagate to an Observer
  //    @Test
  //    public void testFatalError() {
  //        try {
  //            Observable.just(1, 2, 3)
  //                    .flatMap(new Function<Integer, Observable<?>>() {
  //                        @Override
  //                        public Observable<?> apply(Integer integer) {
  //                            return Observable.create(new ObservableSource<Object>() {
  //                                @Override
  //                                public void accept(Observer<Object> o) {
  //                                    throw new NullPointerException("Test NPE");
  //                                }
  //                            });
  //                        }
  //                    })
  //                    .doOnNext(new Consumer<Object>() {
  //                        @Override
  //                        public void accept(Object o) {
  //                            System.out.println("Won't come here");
  //                        }
  //                    })
  //                    .subscribe();
  //            fail("should have thrown an exception");
  //        } catch (OnErrorNotImplementedException e) {
  //            assertTrue(e.getCause() instanceof NullPointerException);
  //            assertEquals(e.getCause().getMessage(), "Test NPE");
  //            System.out.println("Received exception: " + e);
  //        }
  //    }
  
      @Test
      public void onErrorThrows() {
          TestObserverEx<Object> to = new TestObserverEx<>();
  
          Observable.error(new TestException())
          .doOnError(new Consumer<Throwable>() {
              @Override
              public void accept(Throwable e) {
                  throw new TestException();
              }
          }).subscribe(to);
  
          to.assertNoValues();
          to.assertNotComplete();
          to.assertError(CompositeException.class);
  
          CompositeException ex = (CompositeException)to.errors().get(0);
  
          List<Throwable> exceptions = ex.getExceptions();
          assertEquals(2, exceptions.size());
          Assert.assertTrue(exceptions.get(0) instanceof TestException);
          Assert.assertTrue(exceptions.get(1) instanceof TestException);
      }
  
      @Test
      public void ignoreCancel() {
          List<Throwable> errors = TestHelper.trackPluginErrors();
  
          try {
              Observable.wrap(new ObservableSource<Object>() {
                  @Override
                  public void subscribe(Observer<? super Object> observer) {
                      observer.onSubscribe(Disposable.empty());
                      observer.onNext(1);
                      observer.onNext(2);
                      observer.onError(new IOException());
                      observer.onComplete();
                  }
              })
              .doOnNext(new Consumer<Object>() {
                  @Override
                  public void accept(Object e) throws Exception {
                      throw new TestException();
                  }
              })
              .test()
              .assertFailure(TestException.class);
  
              TestHelper.assertUndeliverable(errors, 0, IOException.class);
          } finally {
              RxJavaPlugins.reset();
          }
      }
  
      @Test
      public void onErrorAfterCrash() {
          List<Throwable> errors = TestHelper.trackPluginErrors();
  
          try {
              Observable.wrap(new ObservableSource<Object>() {
                  @Override
                  public void subscribe(Observer<? super Object> observer) {
                      observer.onSubscribe(Disposable.empty());
                      observer.onError(new TestException());
                  }
              })
              .doAfterTerminate(new Action() {
                  @Override
                  public void run() throws Exception {
                      throw new IOException();
                  }
              })
              .test()
              .assertFailure(TestException.class);
  
              TestHelper.assertUndeliverable(errors, 0, IOException.class);
          } finally {
              RxJavaPlugins.reset();
          }
      }
  
      @Test
      public void onCompleteAfterCrash() {
          List<Throwable> errors = TestHelper.trackPluginErrors();
  
          try {
              Observable.wrap(new ObservableSource<Object>() {
                  @Override
                  public void subscribe(Observer<? super Object> observer) {
                      observer.onSubscribe(Disposable.empty());
                      observer.onComplete();
                  }
              })
              .doAfterTerminate(new Action() {
                  @Override
                  public void run() throws Exception {
                      throw new IOException();
                  }
              })
              .test()
              .assertResult();
  
              TestHelper.assertUndeliverable(errors, 0, IOException.class);
          } finally {
              RxJavaPlugins.reset();
          }
      }
  
      @Test
      public void onCompleteCrash() {
          Observable.wrap(new ObservableSource<Object>() {
              @Override
              public void subscribe(Observer<? super Object> observer) {
                  observer.onSubscribe(Disposable.empty());
                  observer.onComplete();
              }
          })
          .doOnComplete(new Action() {
              @Override
              public void run() throws Exception {
                  throw new IOException();
              }
          })
          .test()
          .assertFailure(IOException.class);
      }
  
      @Test
      public void ignoreCancelConditional() {
          List<Throwable> errors = TestHelper.trackPluginErrors();
  
          try {
              Observable.wrap(new ObservableSource<Object>() {
                  @Override
                  public void subscribe(Observer<? super Object> observer) {
                      observer.onSubscribe(Disposable.empty());
                      observer.onNext(1);
                      observer.onNext(2);
                      observer.onError(new IOException());
                      observer.onComplete();
                  }
              })
              .doOnNext(new Consumer<Object>() {
                  @Override
                  public void accept(Object e) throws Exception {
                      throw new TestException();
                  }
              })
              .filter(Functions.alwaysTrue())
              .test()
              .assertFailure(TestException.class);
  
              TestHelper.assertUndeliverable(errors, 0, IOException.class);
          } finally {
              RxJavaPlugins.reset();
          }
      }
  
      @Test
      public void onErrorAfterCrashConditional() {
          List<Throwable> errors = TestHelper.trackPluginErrors();
  
          try {
              Observable.wrap(new ObservableSource<Object>() {
                  @Override
                  public void subscribe(Observer<? super Object> observer) {
                      observer.onSubscribe(Disposable.empty());
                      observer.onError(new TestException());
                  }
              })
              .doAfterTerminate(new Action() {
                  @Override
                  public void run() throws Exception {
                      throw new IOException();
                  }
              })
              .filter(Functions.alwaysTrue())
              .test()
              .assertFailure(TestException.class);
  
              TestHelper.assertUndeliverable(errors, 0, IOException.class);
          } finally {
              RxJavaPlugins.reset();
          }
      }
  
      @Test
      public void onCompleteAfter() {
          final int[] call = { 0 };
          Observable.just(1)
          .doAfterTerminate(new Action() {
              @Override
              public void run() throws Exception {
                  call[0]++;
              }
          })
          .test()
          .assertResult(1);
  
          assertEquals(1, call[0]);
      }
  
      @Test
      public void onCompleteAfterCrashConditional() {
          List<Throwable> errors = TestHelper.trackPluginErrors();
  
          try {
              Observable.wrap(new ObservableSource<Object>() {
                  @Override
                  public void subscribe(Observer<? super Object> observer) {
                      observer.onSubscribe(Disposable.empty());
                      observer.onComplete();
                  }
              })
              .doAfterTerminate(new Action() {
                  @Override
                  public void run() throws Exception {
                      throw new IOException();
                  }
              })
              .filter(Functions.alwaysTrue())
              .test()
              .assertResult();
  
              TestHelper.assertUndeliverable(errors, 0, IOException.class);
          } finally {
              RxJavaPlugins.reset();
          }
      }
  
      @Test
      public void onCompleteCrashConditional() {
          Observable.wrap(new ObservableSource<Object>() {
              @Override
              public void subscribe(Observer<? super Object> observer) {
                  observer.onSubscribe(Disposable.empty());
                  observer.onComplete();
              }
          })
          .doOnComplete(new Action() {
              @Override
              public void run() throws Exception {
                  throw new IOException();
              }
          })
          .filter(Functions.alwaysTrue())
          .test()
          .assertFailure(IOException.class);
      }
  
      @Test
      public void onErrorOnErrorCrashConditional() {
          TestObserverEx<Object> to = Observable.error(new TestException("Outer"))
          .doOnError(new Consumer<Throwable>() {
              @Override
              public void accept(Throwable e) throws Exception {
                  throw new TestException("Inner");
              }
          })
          .filter(Functions.alwaysTrue())
          .to(TestHelper.testConsumer())
          .assertFailure(CompositeException.class);
  
          List<Throwable> errors = TestHelper.compositeList(to.errors().get(0));
  
          TestHelper.assertError(errors, 0, TestException.class, "Outer");
          TestHelper.assertError(errors, 1, TestException.class, "Inner");
      }
  
      @Test
      @Ignore("Fusion not supported yet") // TODO decide/implement fusion
      public void fused() {
          TestObserverEx<Integer> to = new TestObserverEx<>(QueueFuseable.ANY);
  
          final int[] call = { 0, 0 };
  
          Observable.range(1, 5)
          .doOnNext(new Consumer<Integer>() {
              @Override
              public void accept(Integer v) throws Exception {
                  call[0]++;
              }
          })
          .doOnComplete(new Action() {
              @Override
              public void run() throws Exception {
                  call[1]++;
              }
          })
          .subscribe(to);
  
          to.assertFuseable()
          .assertFusionMode(QueueFuseable.SYNC)
          .assertResult(1, 2, 3, 4, 5);
  
          assertEquals(5, call[0]);
          assertEquals(1, call[1]);
      }
  
      @Test
      @Ignore("Fusion not supported yet") // TODO decide/implement fusion
      public void fusedOnErrorCrash() {
          TestObserverEx<Integer> to = new TestObserverEx<>(QueueFuseable.ANY);
  
          final int[] call = { 0 };
  
          Observable.range(1, 5)
          .doOnNext(new Consumer<Integer>() {
              @Override
              public void accept(Integer v) throws Exception {
                  throw new TestException();
              }
          })
          .doOnComplete(new Action() {
              @Override
              public void run() throws Exception {
                  call[0]++;
              }
          })
          .subscribe(to);
  
          to.assertFuseable()
          .assertFusionMode(QueueFuseable.SYNC)
          .assertFailure(TestException.class);
  
          assertEquals(0, call[0]);
      }
  
      @Test
      @Ignore("Fusion not supported yet") // TODO decide/implement fusion
      public void fusedConditional() {
          TestObserverEx<Integer> to = new TestObserverEx<>(QueueFuseable.ANY);
  
          final int[] call = { 0, 0 };
  
          Observable.range(1, 5)
          .doOnNext(new Consumer<Integer>() {
              @Override
              public void accept(Integer v) throws Exception {
                  call[0]++;
              }
          })
          .doOnComplete(new Action() {
              @Override
              public void run() throws Exception {
                  call[1]++;
              }
          })
          .filter(Functions.alwaysTrue())
          .subscribe(to);
  
          to.assertFuseable()
          .assertFusionMode(QueueFuseable.SYNC)
          .assertResult(1, 2, 3, 4, 5);
  
          assertEquals(5, call[0]);
          assertEquals(1, call[1]);
      }
  
      @Test
      @Ignore("Fusion not supported yet") // TODO decide/implement fusion
      public void fusedOnErrorCrashConditional() {
          TestObserverEx<Integer> to = new TestObserverEx<>(QueueFuseable.ANY);
  
          final int[] call = { 0 };
  
          Observable.range(1, 5)
          .doOnNext(new Consumer<Integer>() {
              @Override
              public void accept(Integer v) throws Exception {
                  throw new TestException();
              }
          })
          .doOnComplete(new Action() {
              @Override
              public void run() throws Exception {
                  call[0]++;
              }
          })
          .filter(Functions.alwaysTrue())
          .subscribe(to);
  
          to.assertFuseable()
          .assertFusionMode(QueueFuseable.SYNC)
          .assertFailure(TestException.class);
  
          assertEquals(0, call[0]);
      }
  
      @Test
      @Ignore("Fusion not supported yet") // TODO decide/implement fusion
      public void fusedAsync() {
          TestObserverEx<Integer> to = new TestObserverEx<>(QueueFuseable.ANY);
  
          final int[] call = { 0, 0 };
  
          UnicastSubject<Integer> us = UnicastSubject.create();
  
          us
          .doOnNext(new Consumer<Integer>() {
              @Override
              public void accept(Integer v) throws Exception {
                  call[0]++;
              }
          })
          .doOnComplete(new Action() {
              @Override
              public void run() throws Exception {
                  call[1]++;
              }
          })
          .subscribe(to);
  
          TestHelper.emit(us, 1, 2, 3, 4, 5);
  
          to.assertFuseable()
          .assertFusionMode(QueueFuseable.ASYNC)
          .assertResult(1, 2, 3, 4, 5);
  
          assertEquals(5, call[0]);
          assertEquals(1, call[1]);
      }
  
      @Test
      @Ignore("Fusion not supported yet") // TODO decide/implement fusion
      public void fusedAsyncConditional() {
          TestObserverEx<Integer> to = new TestObserverEx<>(QueueFuseable.ANY);
  
          final int[] call = { 0, 0 };
  
          UnicastSubject<Integer> us = UnicastSubject.create();
  
          us
          .doOnNext(new Consumer<Integer>() {
              @Override
              public void accept(Integer v) throws Exception {
                  call[0]++;
              }
          })
          .doOnComplete(new Action() {
              @Override
              public void run() throws Exception {
                  call[1]++;
              }
          })
          .filter(Functions.alwaysTrue())
          .subscribe(to);
  
          TestHelper.emit(us, 1, 2, 3, 4, 5);
  
          to.assertFuseable()
          .assertFusionMode(QueueFuseable.ASYNC)
          .assertResult(1, 2, 3, 4, 5);
  
          assertEquals(5, call[0]);
          assertEquals(1, call[1]);
      }
  
      @Test
      @Ignore("Fusion not supported yet") // TODO decide/implement fusion
      public void fusedAsyncConditional2() {
          TestObserverEx<Integer> to = new TestObserverEx<>(QueueFuseable.ANY);
  
          final int[] call = { 0, 0 };
  
          UnicastSubject<Integer> us = UnicastSubject.create();
  
          us.hide()
          .doOnNext(new Consumer<Integer>() {
              @Override
              public void accept(Integer v) throws Exception {
                  call[0]++;
              }
          })
          .doOnComplete(new Action() {
              @Override
              public void run() throws Exception {
                  call[1]++;
              }
          })
          .filter(Functions.alwaysTrue())
          .subscribe(to);
  
          TestHelper.emit(us, 1, 2, 3, 4, 5);
  
          to.assertFuseable()
          .assertFusionMode(QueueFuseable.NONE)
          .assertResult(1, 2, 3, 4, 5);
  
          assertEquals(5, call[0]);
          assertEquals(1, call[1]);
      }
  
      @Test
      public void dispose() {
          TestHelper.checkDisposed(Observable.just(1).doOnEach(new TestObserver<>()));
      }
  
      @Test
      public void doubleOnSubscribe() {
          TestHelper.checkDoubleOnSubscribeObservable(new Function<Observable<Object>, ObservableSource<Object>>() {
              @Override
              public ObservableSource<Object> apply(Observable<Object> o) throws Exception {
                  return o.doOnEach(new TestObserver<>());
              }
          });
      }
  }
  