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.mixed;
  
  import static org.junit.Assert.*;
  
  import java.util.List;
  import java.util.concurrent.atomic.AtomicReference;
  
  import io.reactivex.rxjava3.disposables.Disposable;
  import org.junit.Test;
  import org.reactivestreams.*;
  
  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.internal.subscriptions.BooleanSubscription;
  import io.reactivex.rxjava3.plugins.RxJavaPlugins;
  import io.reactivex.rxjava3.processors.PublishProcessor;
  import io.reactivex.rxjava3.subjects.SingleSubject;
  import io.reactivex.rxjava3.subscribers.TestSubscriber;
  import io.reactivex.rxjava3.testsupport.*;
  
  public class FlowableSwitchMapSingleTest extends RxJavaTest {
  
      @Test
      public void simple() {
          Flowable.range(1, 5)
          .switchMapSingle(new Function<Integer, SingleSource<Integer>>() {
              @Override
              public SingleSource<Integer> apply(Integer v)
                      throws Exception {
                  return Single.just(v);
              }
          })
          .test()
          .assertResult(1, 2, 3, 4, 5);
      }
  
      @Test
      public void mainError() {
          Flowable.error(new TestException())
          .switchMapSingle(Functions.justFunction(Single.never()))
          .test()
          .assertFailure(TestException.class);
      }
  
      @Test
      public void innerError() {
          Flowable.just(1)
          .switchMapSingle(Functions.justFunction(Single.error(new TestException())))
          .test()
          .assertFailure(TestException.class);
      }
  
      @Test
      public void doubleOnSubscribe() {
          TestHelper.checkDoubleOnSubscribeFlowable(new Function<Flowable<Object>, Publisher<Object>>() {
              @Override
              public Publisher<Object> apply(Flowable<Object> f)
                      throws Exception {
                  return f
                          .switchMapSingle(Functions.justFunction(Single.never()));
              }
          }
          );
      }
  
      @Test
      public void limit() {
          Flowable.range(1, 5)
          .switchMapSingle(new Function<Integer, SingleSource<Integer>>() {
              @Override
              public SingleSource<Integer> apply(Integer v)
                      throws Exception {
                  return Single.just(v);
              }
          })
          .take(3)
          .test()
          .assertResult(1, 2, 3);
      }
  
      @Test
      public void switchOver() {
          PublishProcessor<Integer> pp = PublishProcessor.create();
  
          final SingleSubject<Integer> ms1 = SingleSubject.create();
          final SingleSubject<Integer> ms2 = SingleSubject.create();
  
          TestSubscriber<Integer> ts = pp.switchMapSingle(new Function<Integer, SingleSource<Integer>>() {
              @Override
              public SingleSource<Integer> apply(Integer v)
                      throws Exception {
                          if (v == 1) {
                              return ms1;
                          }
                          return ms2;
                      }
          }).test();
  
          ts.assertEmpty();
  
          pp.onNext(1);
  
          ts.assertEmpty();
  
          assertTrue(ms1.hasObservers());
  
          pp.onNext(2);
  
          assertFalse(ms1.hasObservers());
          assertTrue(ms2.hasObservers());
  
          ms2.onError(new TestException());
  
          assertFalse(pp.hasSubscribers());
  
          ts.assertFailure(TestException.class);
      }
  
      @Test
      public void switchOverDelayError() {
          PublishProcessor<Integer> pp = PublishProcessor.create();
  
          final SingleSubject<Integer> ms1 = SingleSubject.create();
          final SingleSubject<Integer> ms2 = SingleSubject.create();
  
          TestSubscriber<Integer> ts = pp.switchMapSingleDelayError(new Function<Integer, SingleSource<Integer>>() {
              @Override
              public SingleSource<Integer> apply(Integer v)
                      throws Exception {
                          if (v == 1) {
                              return ms1;
                          }
                          return ms2;
                      }
          }).test();
  
          ts.assertEmpty();
  
          pp.onNext(1);
  
          ts.assertEmpty();
  
          assertTrue(ms1.hasObservers());
  
          pp.onNext(2);
  
          assertFalse(ms1.hasObservers());
          assertTrue(ms2.hasObservers());
  
          ms2.onError(new TestException());
  
          ts.assertEmpty();
  
          assertTrue(pp.hasSubscribers());
  
          pp.onComplete();
  
          ts.assertFailure(TestException.class);
      }
  
      @Test
      public void mainErrorInnerCompleteDelayError() {
          PublishProcessor<Integer> pp = PublishProcessor.create();
  
          final SingleSubject<Integer> ms = SingleSubject.create();
  
          TestSubscriber<Integer> ts = pp.switchMapSingleDelayError(new Function<Integer, SingleSource<Integer>>() {
              @Override
              public SingleSource<Integer> apply(Integer v)
                      throws Exception {
                          return ms;
                      }
          }).test();
  
          ts.assertEmpty();
  
          pp.onNext(1);
  
          ts.assertEmpty();
  
          assertTrue(ms.hasObservers());
  
          pp.onError(new TestException());
  
          assertTrue(ms.hasObservers());
  
          ts.assertEmpty();
  
          ms.onSuccess(1);
  
          ts.assertFailure(TestException.class, 1);
      }
  
      @Test
      public void mainErrorInnerSuccessDelayError() {
          PublishProcessor<Integer> pp = PublishProcessor.create();
  
          final SingleSubject<Integer> ms = SingleSubject.create();
  
          TestSubscriber<Integer> ts = pp.switchMapSingleDelayError(new Function<Integer, SingleSource<Integer>>() {
              @Override
              public SingleSource<Integer> apply(Integer v)
                      throws Exception {
                          return ms;
                      }
          }).test();
  
          ts.assertEmpty();
  
          pp.onNext(1);
  
          ts.assertEmpty();
  
          assertTrue(ms.hasObservers());
  
          pp.onError(new TestException());
  
          assertTrue(ms.hasObservers());
  
          ts.assertEmpty();
  
          ms.onSuccess(1);
  
          ts.assertFailure(TestException.class, 1);
      }
  
      @Test
      public void mapperCrash() {
          Flowable.just(1)
          .switchMapSingle(new Function<Integer, SingleSource<? extends Object>>() {
              @Override
              public SingleSource<? extends Object> apply(Integer v)
                      throws Exception {
                          throw new TestException();
                      }
          })
          .test()
          .assertFailure(TestException.class);
      }
  
      @Test
      public void disposeBeforeSwitchInOnNext() {
          final TestSubscriber<Integer> ts = new TestSubscriber<>();
  
          Flowable.just(1)
          .switchMapSingle(new Function<Integer, SingleSource<Integer>>() {
              @Override
              public SingleSource<Integer> apply(Integer v)
                      throws Exception {
                          ts.cancel();
                          return Single.just(1);
                      }
          }).subscribe(ts);
  
          ts.assertEmpty();
      }
  
      @Test
      public void disposeOnNextAfterFirst() {
          final TestSubscriber<Integer> ts = new TestSubscriber<>();
  
          Flowable.just(1, 2)
          .switchMapSingle(new Function<Integer, SingleSource<Integer>>() {
              @Override
              public SingleSource<Integer> apply(Integer v)
                      throws Exception {
                  if (v == 2) {
                      ts.cancel();
                  }
                  return Single.just(1);
              }
          }).subscribe(ts);
  
          ts.assertValue(1)
          .assertNoErrors()
          .assertNotComplete();
      }
  
      @Test
      public void cancel() {
          PublishProcessor<Integer> pp = PublishProcessor.create();
  
          final SingleSubject<Integer> ms = SingleSubject.create();
  
          TestSubscriber<Integer> ts = pp.switchMapSingleDelayError(new Function<Integer, SingleSource<Integer>>() {
              @Override
              public SingleSource<Integer> apply(Integer v)
                      throws Exception {
                          return ms;
                      }
          }).test();
  
          ts.assertEmpty();
  
          pp.onNext(1);
  
          ts.assertEmpty();
  
          assertTrue(pp.hasSubscribers());
          assertTrue(ms.hasObservers());
  
          ts.cancel();
  
          assertFalse(pp.hasSubscribers());
          assertFalse(ms.hasObservers());
      }
  
      @Test
      public void mainErrorAfterTermination() {
          List<Throwable> errors = TestHelper.trackPluginErrors();
          try {
              new Flowable<Integer>() {
                  @Override
                  protected void subscribeActual(Subscriber<? super Integer> s) {
                      s.onSubscribe(new BooleanSubscription());
                      s.onNext(1);
                      s.onError(new TestException("outer"));
                  }
              }
              .switchMapSingle(new Function<Integer, SingleSource<Integer>>() {
                  @Override
                  public SingleSource<Integer> apply(Integer v)
                          throws Exception {
                      return Single.error(new TestException("inner"));
                  }
              })
              .to(TestHelper.<Integer>testConsumer())
              .assertFailureAndMessage(TestException.class, "inner");
  
              TestHelper.assertUndeliverable(errors, 0, TestException.class, "outer");
          } finally {
              RxJavaPlugins.reset();
          }
      }
  
      @Test
      public void innerErrorAfterTermination() {
          List<Throwable> errors = TestHelper.trackPluginErrors();
          try {
              final AtomicReference<SingleObserver<? super Integer>> moRef = new AtomicReference<>();
  
              TestSubscriberEx<Integer> ts = new Flowable<Integer>() {
                  @Override
                  protected void subscribeActual(Subscriber<? super Integer> s) {
                      s.onSubscribe(new BooleanSubscription());
                      s.onNext(1);
                      s.onError(new TestException("outer"));
                  }
              }
              .switchMapSingle(new Function<Integer, SingleSource<Integer>>() {
                  @Override
                  public SingleSource<Integer> apply(Integer v)
                          throws Exception {
                      return new Single<Integer>() {
                          @Override
                          protected void subscribeActual(
                                  SingleObserver<? super Integer> observer) {
                              observer.onSubscribe(Disposable.empty());
                              moRef.set(observer);
                          }
                      };
                  }
              })
              .to(TestHelper.<Integer>testConsumer());
  
              ts.assertFailureAndMessage(TestException.class, "outer");
  
              moRef.get().onError(new TestException("inner"));
  
              TestHelper.assertUndeliverable(errors, 0, TestException.class, "inner");
          } finally {
              RxJavaPlugins.reset();
          }
      }
  
      @Test
      public void nextCancelRace() {
          for (int i = 0; i < TestHelper.RACE_LONG_LOOPS; i++) {
  
              final PublishProcessor<Integer> pp = PublishProcessor.create();
  
              final SingleSubject<Integer> ms = SingleSubject.create();
  
              final TestSubscriber<Integer> ts = pp.switchMapSingleDelayError(new Function<Integer, SingleSource<Integer>>() {
                  @Override
                  public SingleSource<Integer> apply(Integer v)
                          throws Exception {
                              return ms;
                          }
              }).test();
  
              Runnable r1 = new Runnable() {
                  @Override
                  public void run() {
                      pp.onNext(1);
                  }
              };
  
              Runnable r2 = new Runnable() {
                  @Override
                  public void run() {
                      ts.cancel();
                  }
              };
  
              TestHelper.race(r1, r2);
  
              ts.assertNoErrors()
              .assertNotComplete();
          }
      }
  
      @Test
      public void nextInnerErrorRace() {
          final TestException ex = new TestException();
  
          for (int i = 0; i < TestHelper.RACE_LONG_LOOPS; i++) {
  
              List<Throwable> errors = TestHelper.trackPluginErrors();
              try {
                  final PublishProcessor<Integer> pp = PublishProcessor.create();
  
                  final SingleSubject<Integer> ms = SingleSubject.create();
  
                  final TestSubscriberEx<Integer> ts = pp.switchMapSingleDelayError(new Function<Integer, SingleSource<Integer>>() {
                      @Override
                      public SingleSource<Integer> apply(Integer v)
                              throws Exception {
                          if (v == 1) {
                              return ms;
                          }
                          return Single.never();
                      }
                  }).to(TestHelper.<Integer>testConsumer());
  
                  pp.onNext(1);
  
                  Runnable r1 = new Runnable() {
                      @Override
                      public void run() {
                          pp.onNext(2);
                      }
                  };
  
                  Runnable r2 = new Runnable() {
                      @Override
                      public void run() {
                          ms.onError(ex);
                      }
                  };
  
                  TestHelper.race(r1, r2);
  
                  if (ts.errors().size() != 0) {
                      assertTrue(errors.isEmpty());
                      ts.assertFailure(TestException.class);
                  } else if (!errors.isEmpty()) {
                      TestHelper.assertUndeliverable(errors, 0, TestException.class);
                  }
              } finally {
                  RxJavaPlugins.reset();
              }
          }
      }
  
      @Test
      public void mainErrorInnerErrorRace() {
          final TestException ex = new TestException();
          final TestException ex2 = new TestException();
  
          for (int i = 0; i < TestHelper.RACE_LONG_LOOPS; i++) {
  
              List<Throwable> errors = TestHelper.trackPluginErrors();
              try {
                  final PublishProcessor<Integer> pp = PublishProcessor.create();
  
                  final SingleSubject<Integer> ms = SingleSubject.create();
  
                  final TestSubscriber<Integer> ts = pp.switchMapSingleDelayError(new Function<Integer, SingleSource<Integer>>() {
                      @Override
                      public SingleSource<Integer> apply(Integer v)
                              throws Exception {
                          if (v == 1) {
                              return ms;
                          }
                          return Single.never();
                      }
                  }).test();
  
                  pp.onNext(1);
  
                  Runnable r1 = new Runnable() {
                      @Override
                      public void run() {
                          pp.onError(ex);
                      }
                  };
  
                  Runnable r2 = new Runnable() {
                      @Override
                      public void run() {
                          ms.onError(ex2);
                      }
                  };
  
                  TestHelper.race(r1, r2);
  
                  ts.assertError(new Predicate<Throwable>() {
                      @Override
                      public boolean test(Throwable e) throws Exception {
                          return e instanceof TestException || e instanceof CompositeException;
                      }
                  });
  
                  if (!errors.isEmpty()) {
                      TestHelper.assertUndeliverable(errors, 0, TestException.class);
                  }
              } finally {
                  RxJavaPlugins.reset();
              }
          }
      }
  
      @Test
      public void nextInnerSuccessRace() {
          for (int i = 0; i < TestHelper.RACE_LONG_LOOPS; i++) {
  
              final PublishProcessor<Integer> pp = PublishProcessor.create();
  
              final SingleSubject<Integer> ms = SingleSubject.create();
  
              final TestSubscriber<Integer> ts = pp.switchMapSingleDelayError(new Function<Integer, SingleSource<Integer>>() {
                  @Override
                  public SingleSource<Integer> apply(Integer v)
                          throws Exception {
                      if (v == 1) {
                              return ms;
                      }
                      return Single.never();
                  }
              }).test();
  
              pp.onNext(1);
  
              Runnable r1 = new Runnable() {
                  @Override
                  public void run() {
                      pp.onNext(2);
                  }
              };
  
              Runnable r2 = new Runnable() {
                  @Override
                  public void run() {
                      ms.onSuccess(3);
                  }
              };
  
              TestHelper.race(r1, r2);
  
              ts.assertNoErrors()
              .assertNotComplete();
          }
      }
  
      @Test
      public void requestMoreOnNext() {
          TestSubscriber<Integer> ts = new TestSubscriber<Integer>(1) {
              @Override
              public void onNext(Integer t) {
                  super.onNext(t);
                  requestMore(1);
              }
          };
          Flowable.range(1, 5)
          .switchMapSingle(Functions.justFunction(Single.just(1)))
          .subscribe(ts);
  
          ts.assertResult(1, 1, 1, 1, 1);
      }
  
      @Test
      public void backpressured() {
          Flowable.just(1)
          .switchMapSingle(Functions.justFunction(Single.just(1)))
          .test(0)
          .assertEmpty()
          .requestMore(1)
          .assertResult(1);
      }
  
      @Test
      public void undeliverableUponCancel() {
          TestHelper.checkUndeliverableUponCancel(new FlowableConverter<Integer, Flowable<Integer>>() {
              @Override
              public Flowable<Integer> apply(Flowable<Integer> upstream) {
                  return upstream.switchMapSingle(new Function<Integer, Single<Integer>>() {
                      @Override
                      public Single<Integer> apply(Integer v) throws Throwable {
                          return Single.just(v).hide();
                      }
                  });
              }
          });
      }
  
      @Test
      public void undeliverableUponCancelDelayError() {
          TestHelper.checkUndeliverableUponCancel(new FlowableConverter<Integer, Flowable<Integer>>() {
              @Override
              public Flowable<Integer> apply(Flowable<Integer> upstream) {
                  return upstream.switchMapSingleDelayError(new Function<Integer, Single<Integer>>() {
                      @Override
                      public Single<Integer> apply(Integer v) throws Throwable {
                          return Single.just(v).hide();
                      }
                  });
              }
          });
      }
  }
  