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 org.junit.Test;
  import org.reactivestreams.Publisher;
  
  import io.reactivex.rxjava3.core.*;
  import io.reactivex.rxjava3.exceptions.TestException;
  import io.reactivex.rxjava3.functions.Function;
  import io.reactivex.rxjava3.internal.functions.Functions;
  import io.reactivex.rxjava3.processors.PublishProcessor;
  import io.reactivex.rxjava3.subjects.MaybeSubject;
  import io.reactivex.rxjava3.subscribers.TestSubscriber;
  import io.reactivex.rxjava3.testsupport.TestHelper;
  
  public class MaybeFlatMapPublisherTest extends RxJavaTest {
  
      @Test
      public void cancelMain() {
          MaybeSubject<Integer> ms = MaybeSubject.create();
          PublishProcessor<Integer> pp = PublishProcessor.create();
  
          TestSubscriber<Integer> ts = ms.flatMapPublisher(Functions.justFunction(pp))
                  .test();
  
          assertTrue(ms.hasObservers());
          assertFalse(pp.hasSubscribers());
  
          ts.cancel();
  
          assertFalse(ms.hasObservers());
          assertFalse(pp.hasSubscribers());
      }
  
      @Test
      public void cancelOther() {
          MaybeSubject<Integer> ms = MaybeSubject.create();
          PublishProcessor<Integer> pp = PublishProcessor.create();
  
          TestSubscriber<Integer> ts = ms.flatMapPublisher(Functions.justFunction(pp))
                  .test();
  
          assertTrue(ms.hasObservers());
          assertFalse(pp.hasSubscribers());
  
          ms.onSuccess(1);
  
          assertFalse(ms.hasObservers());
          assertTrue(pp.hasSubscribers());
  
          ts.cancel();
  
          assertFalse(ms.hasObservers());
          assertFalse(pp.hasSubscribers());
      }
  
      @Test
      public void mapperCrash() {
          Maybe.just(1).flatMapPublisher(new Function<Integer, Publisher<? extends Object>>() {
              @Override
              public Publisher<? extends Object> apply(Integer v) throws Exception {
                  throw new TestException();
              }
          })
          .test()
          .assertFailure(TestException.class);
      }
  
      @Test
      public void doubleOnSubscribe() {
          TestHelper.checkDoubleOnSubscribeMaybeToFlowable(new Function<Maybe<Object>, Publisher<Object>>() {
              @Override
              public Publisher<Object> apply(Maybe<Object> m) throws Exception {
                  return m.flatMapPublisher(Functions.justFunction(Flowable.never()));
              }
          });
      }
  }
  