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.assertEquals;
  
  import java.util.concurrent.*;
  import java.util.concurrent.atomic.AtomicInteger;
  
  import org.junit.Test;
  import org.reactivestreams.Publisher;
  
  import io.reactivex.rxjava3.core.*;
  import io.reactivex.rxjava3.exceptions.*;
  import io.reactivex.rxjava3.functions.*;
  import io.reactivex.rxjava3.internal.operators.flowable.FlowableConcatMap.SimpleScalarSubscription;
  import io.reactivex.rxjava3.processors.*;
  import io.reactivex.rxjava3.schedulers.Schedulers;
  import io.reactivex.rxjava3.subscribers.TestSubscriber;
  import io.reactivex.rxjava3.testsupport.TestHelper;
  
  public class FlowableConcatMapTest extends RxJavaTest {
  
      @Test
      public void simpleSubscriptionRequest() {
          TestSubscriber<Integer> ts = new TestSubscriber<>(0);
          SimpleScalarSubscription<Integer> ws = new SimpleScalarSubscription<>(1, ts);
          ts.onSubscribe(ws);
  
          ws.request(0);
  
          ts.assertEmpty();
  
          ws.request(1);
  
          ts.assertResult(1);
  
          ws.request(1);
  
          ts.assertResult(1);
      }
  
      @Test
      public void boundaryFusion() {
          Flowable.range(1, 10000)
          .observeOn(Schedulers.single())
          .map(new Function<Integer, String>() {
              @Override
              public String apply(Integer t) throws Exception {
                  String name = Thread.currentThread().getName();
                  if (name.contains("RxSingleScheduler")) {
                      return "RxSingleScheduler";
                  }
                  return name;
              }
          })
          .concatMap(new Function<String, Publisher<? extends Object>>() {
              @Override
              public Publisher<? extends Object> apply(String v)
                      throws Exception {
                  return Flowable.just(v);
              }
          })
          .observeOn(Schedulers.computation())
          .distinct()
          .test()
          .awaitDone(5, TimeUnit.SECONDS)
          .assertResult("RxSingleScheduler");
      }
  
      @Test
      public void innerScalarRequestRace() {
          Flowable<Integer> just = Flowable.just(1);
          int n = 1000;
          for (int i = 0; i < TestHelper.RACE_DEFAULT_LOOPS; i++) {
              PublishProcessor<Flowable<Integer>> source = PublishProcessor.create();
  
              TestSubscriber<Integer> ts = source
                      .concatMap(v -> v, n + 1)
                      .test(1L);
  
              TestHelper.race(() -> {
                  for (int j = 0; j < n; j++) {
                      source.onNext(just);
                  }
              }, () -> {
                  for (int j = 0; j < n; j++) {
                      ts.request(1);
                  }
              });
  
              ts.assertValueCount(n);
          }
      }
  
      @Test
      public void innerScalarRequestRaceDelayError() {
          Flowable<Integer> just = Flowable.just(1);
          int n = 1000;
          for (int i = 0; i < TestHelper.RACE_DEFAULT_LOOPS; i++) {
              PublishProcessor<Flowable<Integer>> source = PublishProcessor.create();
  
              TestSubscriber<Integer> ts = source
                      .concatMapDelayError(v -> v, true, n + 1)
                      .test(1L);
  
              TestHelper.race(() -> {
                  for (int j = 0; j < n; j++) {
                      source.onNext(just);
                  }
              }, () -> {
                  for (int j = 0; j < n; j++) {
                      ts.request(1);
                  }
              });
  
              ts.assertValueCount(n);
          }
      }
  
      @Test
      public void boundaryFusionDelayError() {
          Flowable.range(1, 10000)
          .observeOn(Schedulers.single())
          .map(new Function<Integer, String>() {
              @Override
              public String apply(Integer t) throws Exception {
                  String name = Thread.currentThread().getName();
                  if (name.contains("RxSingleScheduler")) {
                      return "RxSingleScheduler";
                  }
                  return name;
              }
          })
          .concatMapDelayError(new Function<String, Publisher<? extends Object>>() {
              @Override
              public Publisher<? extends Object> apply(String v)
                      throws Exception {
                  return Flowable.just(v);
              }
          })
          .observeOn(Schedulers.computation())
          .distinct()
          .test()
          .awaitDone(5, TimeUnit.SECONDS)
          .assertResult("RxSingleScheduler");
      }
  
      @Test
      public void pollThrows() {
          Flowable.just(1)
          .map(new Function<Integer, Integer>() {
              @Override
              public Integer apply(Integer v) throws Exception {
                  throw new TestException();
              }
          })
          .compose(TestHelper.<Integer>flowableStripBoundary())
          .concatMap(new Function<Integer, Publisher<Integer>>() {
              @Override
              public Publisher<Integer> apply(Integer v)
                      throws Exception {
                  return Flowable.just(v);
              }
          })
          .test()
          .assertFailure(TestException.class);
      }
  
      @Test
      public void pollThrowsDelayError() {
          Flowable.just(1)
          .map(new Function<Integer, Integer>() {
              @Override
              public Integer apply(Integer v) throws Exception {
                  throw new TestException();
              }
          })
          .compose(TestHelper.<Integer>flowableStripBoundary())
          .concatMapDelayError(new Function<Integer, Publisher<Integer>>() {
              @Override
              public Publisher<Integer> apply(Integer v)
                      throws Exception {
                  return Flowable.just(v);
              }
          })
          .test()
          .assertFailure(TestException.class);
      }
  
      @Test
      public void noCancelPrevious() {
          final AtomicInteger counter = new AtomicInteger();
  
          Flowable.range(1, 5)
          .concatMap(new Function<Integer, Flowable<Integer>>() {
              @Override
              public Flowable<Integer> apply(Integer v) throws Exception {
                  return Flowable.just(v).doOnCancel(new Action() {
                      @Override
                      public void run() throws Exception {
                          counter.getAndIncrement();
                      }
                  });
              }
          })
          .test()
          .assertResult(1, 2, 3, 4, 5);
  
          assertEquals(0, counter.get());
      }
  
      @Test
      public void delayErrorCallableTillTheEnd() {
          Flowable.just(1, 2, 3, 101, 102, 23, 890, 120, 32)
          .concatMapDelayError(new Function<Integer, Flowable<Integer>>() {
            @Override public Flowable<Integer> apply(final Integer integer) throws Exception {
              return Flowable.fromCallable(new Callable<Integer>() {
                @Override public Integer call() throws Exception {
                  if (integer >= 100) {
                    throw new NullPointerException("test null exp");
                  }
                  return integer;
                }
              });
            }
          })
          .test()
          .assertFailure(CompositeException.class, 1, 2, 3, 23, 32);
      }
  
      @Test
      public void delayErrorCallableEager() {
          Flowable.just(1, 2, 3, 101, 102, 23, 890, 120, 32)
          .concatMapDelayError(new Function<Integer, Flowable<Integer>>() {
            @Override public Flowable<Integer> apply(final Integer integer) throws Exception {
              return Flowable.fromCallable(new Callable<Integer>() {
                @Override public Integer call() throws Exception {
                  if (integer >= 100) {
                    throw new NullPointerException("test null exp");
                  }
                  return integer;
                }
              });
            }
          }, false, 2)
          .test()
          .assertFailure(NullPointerException.class, 1, 2, 3);
      }
  
      @Test
      public void undeliverableUponCancel() {
          TestHelper.checkUndeliverableUponCancel(new FlowableConverter<Integer, Flowable<Integer>>() {
              @Override
              public Flowable<Integer> apply(Flowable<Integer> upstream) {
                  return upstream.concatMap(new Function<Integer, Publisher<Integer>>() {
                      @Override
                      public Publisher<Integer> apply(Integer v) throws Throwable {
                          return Flowable.just(v).hide();
                      }
                  });
              }
          });
      }
  
      @Test
      public void undeliverableUponCancelDelayError() {
          TestHelper.checkUndeliverableUponCancel(new FlowableConverter<Integer, Flowable<Integer>>() {
              @Override
              public Flowable<Integer> apply(Flowable<Integer> upstream) {
                  return upstream.concatMapDelayError(new Function<Integer, Publisher<Integer>>() {
                      @Override
                      public Publisher<Integer> apply(Integer v) throws Throwable {
                          return Flowable.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.concatMapDelayError(new Function<Integer, Publisher<Integer>>() {
                      @Override
                      public Publisher<Integer> apply(Integer v) throws Throwable {
                          return Flowable.just(v).hide();
                      }
                  }, true, 2);
              }
          });
      }
  
      @Test
      public void asyncFusedSource() {
          UnicastProcessor<Integer> up = UnicastProcessor.create();
          up.onNext(1);
          up.onComplete();
  
          up.concatMap(v -> Flowable.just(1).hide())
          .test()
          .assertResult(1);
      }
  
      @Test
      public void scalarCallableSource() {
          Flowable.fromCallable(() -> 1)
          .concatMap(v -> Flowable.just(1))
          .test()
          .assertResult(1);
      }
  }
  