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.maybe;
  
  import static org.junit.Assert.assertEquals;
  
  import java.util.*;
  
  import org.junit.Test;
  
  import io.reactivex.rxjava3.core.*;
  import io.reactivex.rxjava3.exceptions.TestException;
  import io.reactivex.rxjava3.functions.Function;
  import io.reactivex.rxjava3.internal.util.CrashingMappedIterable;
  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 MaybeConcatIterableTest extends RxJavaTest {
  
      @Test
      public void take() {
          Maybe.concat(Arrays.asList(Maybe.just(1), Maybe.just(2), Maybe.just(3)))
          .take(1)
          .test()
          .assertResult(1);
      }
  
      @Test
      public void iteratorThrows() {
          Maybe.concat(new Iterable<MaybeSource<Object>>() {
              @Override
              public Iterator<MaybeSource<Object>> iterator() {
                  throw new TestException("iterator()");
              }
          })
          .to(TestHelper.<Object>testConsumer())
          .assertFailureAndMessage(TestException.class, "iterator()");
      }
  
      @Test
      public void error() {
          Maybe.concat(Arrays.asList(Maybe.just(1), Maybe.<Integer>error(new TestException()), Maybe.just(3)))
          .test()
          .assertFailure(TestException.class, 1);
      }
  
      @Test
      public void successCancelRace() {
          for (int i = 0; i < TestHelper.RACE_DEFAULT_LOOPS; i++) {
  
              final PublishProcessor<Integer> pp = PublishProcessor.create();
  
              final TestSubscriber<Integer> ts = Maybe.concat(Arrays.asList(pp.singleElement()))
              .test();
  
              pp.onNext(1);
  
              Runnable r1 = new Runnable() {
                  @Override
                  public void run() {
                      ts.cancel();
                  }
              };
  
              Runnable r2 = new Runnable() {
                  @Override
                  public void run() {
                      pp.onComplete();
                  }
              };
  
              TestHelper.race(r1, r2);
          }
      }
  
      @Test
      public void hasNextThrows() {
          Maybe.concat(new CrashingMappedIterable<>(100, 1, 100, new Function<Integer, Maybe<Integer>>() {
              @Override
              public Maybe<Integer> apply(Integer v) throws Exception {
                  return Maybe.just(1);
              }
          }))
          .to(TestHelper.<Integer>testConsumer())
          .assertFailureAndMessage(TestException.class, "hasNext()");
      }
  
      @Test
      public void nextThrows() {
          Maybe.concat(new CrashingMappedIterable<>(100, 100, 1, new Function<Integer, Maybe<Integer>>() {
              @Override
              public Maybe<Integer> apply(Integer v) throws Exception {
                  return Maybe.just(1);
              }
          }))
          .to(TestHelper.<Integer>testConsumer())
          .assertFailureAndMessage(TestException.class, "next()");
      }
  
      @Test
      public void nextReturnsNull() {
          Maybe.concat(new CrashingMappedIterable<>(100, 100, 100, new Function<Integer, Maybe<Integer>>() {
              @Override
              public Maybe<Integer> apply(Integer v) throws Exception {
                  return null;
              }
          }))
          .test()
          .assertFailure(NullPointerException.class);
      }
  
      @Test
      public void noSubsequentSubscription() {
          final int[] calls = { 0 };
  
          Maybe<Integer> source = Maybe.create(new MaybeOnSubscribe<Integer>() {
              @Override
              public void subscribe(MaybeEmitter<Integer> s) throws Exception {
                  calls[0]++;
                  s.onSuccess(1);
              }
          });
  
          Maybe.concat(Arrays.asList(source, source)).firstElement()
          .test()
          .assertResult(1);
  
          assertEquals(1, calls[0]);
      }
  
      @Test
      public void noSubsequentSubscriptionDelayError() {
          final int[] calls = { 0 };
  
          Maybe<Integer> source = Maybe.create(new MaybeOnSubscribe<Integer>() {
              @Override
              public void subscribe(MaybeEmitter<Integer> s) throws Exception {
                  calls[0]++;
                  s.onSuccess(1);
              }
          });
  
          Maybe.concatDelayError(Arrays.asList(source, source)).firstElement()
          .test()
          .assertResult(1);
  
          assertEquals(1, calls[0]);
      }
  
      @Test
      public void badRequest() {
          TestHelper.assertBadRequestReported(Maybe.concat(Arrays.asList(
                  MaybeSubject.create(),
                  MaybeSubject.create()
          )));
      }
  }
  