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.Subscriber;
  
  import io.reactivex.rxjava3.core.*;
  import io.reactivex.rxjava3.exceptions.*;
  import io.reactivex.rxjava3.functions.Function;
  import io.reactivex.rxjava3.internal.functions.Functions;
  import io.reactivex.rxjava3.internal.operators.mixed.FlowableConcatMapSingle.ConcatMapSingleSubscriber;
  import io.reactivex.rxjava3.internal.subscriptions.BooleanSubscription;
  import io.reactivex.rxjava3.internal.util.ErrorMode;
  import io.reactivex.rxjava3.plugins.RxJavaPlugins;
  import io.reactivex.rxjava3.processors.*;
  import io.reactivex.rxjava3.subjects.SingleSubject;
  import io.reactivex.rxjava3.subscribers.TestSubscriber;
  import io.reactivex.rxjava3.testsupport.*;
  
  public class FlowableConcatMapSingleTest extends RxJavaTest {
  
      @Test
      public void simple() {
          Flowable.range(1, 5)
          .concatMapSingle(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 simpleLongPrefetch() {
          Flowable.range(1, 1024)
          .concatMapSingle(Single::just, 32)
          .test()
          .assertValueCount(1024)
          .assertNoErrors()
          .assertComplete();
      }
  
      @Test
      public void simpleLongPrefetchHidden() {
          Flowable.range(1, 1024).hide()
          .concatMapSingle(Single::just, 32)
          .test()
          .assertValueCount(1024)
          .assertNoErrors()
          .assertComplete();
      }
  
      @Test
      public void backpressure() {
          TestSubscriber<Integer> ts = Flowable.range(1, 1024)
          .concatMapSingle(new Function<Integer, SingleSource<Integer>>() {
              @Override
              public SingleSource<Integer> apply(Integer v)
                      throws Exception {
                  return Single.just(v);
              }
          }, 32)
          .test(0);
  
          for (int i = 1; i <= 1024; i++) {
              ts.assertValueCount(i - 1)
              .assertNoErrors()
              .assertNotComplete()
              .requestMore(1)
              .assertValueCount(i)
              .assertNoErrors();
          }
  
          ts.assertComplete();
      }
  
      @Test
      public void mainError() {
          Flowable.error(new TestException())
          .concatMapSingle(Functions.justFunction(Single.just(1)))
          .test()
          .assertFailure(TestException.class);
      }
  
      @Test
      public void innerError() {
          Flowable.just(1)
          .concatMapSingle(Functions.justFunction(Single.error(new TestException())))
          .test()
          .assertFailure(TestException.class);
      }
  
      @Test
      public void mainBoundaryErrorInnerSuccess() {
          PublishProcessor<Integer> pp = PublishProcessor.create();
          SingleSubject<Integer> ms = SingleSubject.create();
  
          TestSubscriber<Integer> ts = pp.concatMapSingleDelayError(Functions.justFunction(ms), false).test();
  
          ts.assertEmpty();
  
          pp.onNext(1);
  
          assertTrue(ms.hasObservers());
  
          pp.onError(new TestException());
  
          assertTrue(ms.hasObservers());
  
          ts.assertEmpty();
  
          ms.onSuccess(1);
  
          ts.assertFailure(TestException.class, 1);
      }
  
      @Test
      public void doubleOnSubscribe() {
          TestHelper.checkDoubleOnSubscribeFlowable(
                  new Function<Flowable<Object>, Flowable<Object>>() {
                      @Override
                      public Flowable<Object> apply(Flowable<Object> f)
                              throws Exception {
                          return f.concatMapSingleDelayError(
                                  Functions.justFunction(Single.just((Object)1)));
                      }
                  }
          );
      }
  
      @Test
      public void queueOverflow() {
          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.onNext(2);
                      s.onNext(3);
                      s.onError(new TestException());
                  }
              }
              .concatMapSingle(
                      Functions.justFunction(Single.never()), 1
              )
              .test()
              .assertFailure(QueueOverflowException.class);
  
              TestHelper.assertUndeliverable(errors, 0, TestException.class);
          } finally {
              RxJavaPlugins.reset();
          }
      }
  
      @Test
      public void limit() {
          Flowable.range(1, 5)
          .concatMapSingle(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 cancel() {
          Flowable.range(1, 5)
          .concatMapSingle(new Function<Integer, SingleSource<Integer>>() {
              @Override
              public SingleSource<Integer> apply(Integer v)
                      throws Exception {
                  return Single.just(v);
              }
          })
          .test(3)
          .assertValues(1, 2, 3)
          .assertNoErrors()
          .assertNotComplete()
          .cancel();
      }
  
      @Test
      public void innerErrorAfterMainError() {
          List<Throwable> errors = TestHelper.trackPluginErrors();
          try {
              final PublishProcessor<Integer> pp = PublishProcessor.create();
  
              final AtomicReference<SingleObserver<? super Integer>> obs = new AtomicReference<>();
  
              TestSubscriberEx<Integer> ts = pp.concatMapSingle(
                      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());
                                          obs.set(observer);
                                      }
                              };
                          }
                      }
              ).to(TestHelper.<Integer>testConsumer());
  
              pp.onNext(1);
  
              pp.onError(new TestException("outer"));
              obs.get().onError(new TestException("inner"));
  
              ts.assertFailureAndMessage(TestException.class, "outer");
  
              TestHelper.assertUndeliverable(errors, 0, TestException.class, "inner");
          } finally {
              RxJavaPlugins.reset();
          }
      }
  
      @Test
      public void delayAllErrors() {
          TestSubscriberEx<Object> ts = Flowable.range(1, 5)
          .concatMapSingleDelayError(new Function<Integer, SingleSource<? extends Object>>() {
              @Override
              public SingleSource<? extends Object> apply(Integer v)
                      throws Exception {
                  return Single.error(new TestException());
              }
          })
          .to(TestHelper.<Object>testConsumer())
          .assertFailure(CompositeException.class)
          ;
  
          CompositeException ce = (CompositeException)ts.errors().get(0);
          assertEquals(5, ce.getExceptions().size());
      }
  
      @Test
      public void mapperCrash() {
          final PublishProcessor<Integer> pp = PublishProcessor.create();
  
          TestSubscriber<Object> ts = pp
          .concatMapSingle(new Function<Integer, SingleSource<? extends Object>>() {
              @Override
              public SingleSource<? extends Object> apply(Integer v)
                      throws Exception {
                          throw new TestException();
                      }
          })
          .test();
  
          ts.assertEmpty();
  
          assertTrue(pp.hasSubscribers());
  
          pp.onNext(1);
  
          ts.assertFailure(TestException.class);
  
          assertFalse(pp.hasSubscribers());
      }
  
      @Test
      public void cancelNoConcurrentClean() {
          TestSubscriber<Integer> ts = new TestSubscriber<>();
          ConcatMapSingleSubscriber<Integer, Integer> operator =
                  new ConcatMapSingleSubscriber<>(
                          ts, Functions.justFunction(Single.<Integer>never()), 16, ErrorMode.IMMEDIATE);
  
          operator.onSubscribe(new BooleanSubscription());
  
          operator.queue.offer(1);
  
          operator.getAndIncrement();
  
          ts.cancel();
  
          assertFalse(operator.queue.isEmpty());
  
          operator.addAndGet(-2);
  
          operator.cancel();
  
          assertTrue(operator.queue.isEmpty());
      }
  
      @Test
      public void innerSuccessDisposeRace() {
          for (int i = 0; i < TestHelper.RACE_LONG_LOOPS; i++) {
  
              final SingleSubject<Integer> ss = SingleSubject.create();
  
              final TestSubscriber<Integer> ts = Flowable.just(1)
                      .hide()
                      .concatMapSingle(Functions.justFunction(ss))
                      .test();
  
              Runnable r1 = new Runnable() {
                  @Override
                  public void run() {
                      ss.onSuccess(1);
                  }
              };
              Runnable r2 = new Runnable() {
                  @Override
                  public void run() {
                      ts.cancel();
                  }
              };
  
              TestHelper.race(r1, r2);
  
              ts.assertNoErrors();
          }
      }
  
      @Test
      public void undeliverableUponCancel() {
          TestHelper.checkUndeliverableUponCancel(new FlowableConverter<Integer, Flowable<Integer>>() {
              @Override
              public Flowable<Integer> apply(Flowable<Integer> upstream) {
                  return upstream.concatMapSingle(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.concatMapSingleDelayError(new Function<Integer, Single<Integer>>() {
                      @Override
                      public Single<Integer> apply(Integer v) throws Throwable {
                          return Single.just(v).hide();
                      }
                  }, false, 2);
              }
          });
      }
  
      @Test
      public void undeliverableUponCancelDelayErrorTillEnd() {
          TestHelper.checkUndeliverableUponCancel(new FlowableConverter<Integer, Flowable<Integer>>() {
              @Override
              public Flowable<Integer> apply(Flowable<Integer> upstream) {
                  return upstream.concatMapSingleDelayError(new Function<Integer, Single<Integer>>() {
                      @Override
                      public Single<Integer> apply(Integer v) throws Throwable {
                          return Single.just(v).hide();
                      }
                  }, true, 2);
              }
          });
      }
  
      @Test
      public void basicNonFused() {
          Flowable.range(1, 5).hide()
          .concatMapSingle(v -> Single.just(v).hide())
          .test()
          .assertResult(1, 2, 3, 4, 5);
      }
  
      @Test
      public void basicSyncFused() {
          Flowable.range(1, 5)
          .concatMapSingle(v -> Single.just(v).hide())
          .test()
          .assertResult(1, 2, 3, 4, 5);
      }
  
      @Test
      public void basicAsyncFused() {
          UnicastProcessor<Integer> up = UnicastProcessor.create();
          TestHelper.emit(up, 1, 2, 3, 4, 5);
  
          up
          .concatMapSingle(v -> Single.just(v).hide())
          .test()
          .assertResult(1, 2, 3, 4, 5);
      }
  
      @Test
      public void basicFusionRejected() {
          TestHelper.<Integer>rejectFlowableFusion()
          .concatMapSingle(v -> Single.just(v).hide())
          .test()
          .assertEmpty();
      }
  
      @Test
      public void fusedPollCrash() {
          Flowable.range(1, 5)
          .map(v -> {
              if (v == 3) {
                  throw new TestException();
              }
              return v;
          })
          .compose(TestHelper.flowableStripBoundary())
          .concatMapSingle(v -> Single.just(v).hide())
          .test()
          .assertFailure(TestException.class, 1, 2);
      }
  }
  