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.observable;
  
  import static org.junit.Assert.assertEquals;
  
  import java.util.*;
  import java.util.concurrent.atomic.AtomicInteger;
  
  import org.junit.Test;
  
  import io.reactivex.rxjava3.core.Observable;
  import io.reactivex.rxjava3.core.RxJavaTest;
  import io.reactivex.rxjava3.exceptions.TestException;
  import io.reactivex.rxjava3.functions.*;
  import io.reactivex.rxjava3.subjects.PublishSubject;
  import io.reactivex.rxjava3.testsupport.TestHelper;
  
  public class ObservableFlattenIterableTest extends RxJavaTest {
  
      @Test
      public void dispose() {
          TestHelper.checkDisposed(PublishSubject.create().flatMapIterable(new Function<Object, Iterable<Integer>>() {
              @Override
              public Iterable<Integer> apply(Object v) throws Exception {
                  return Arrays.asList(10, 20);
              }
          }));
      }
  
      @Test
      public void badSource() {
          TestHelper.checkBadSourceObservable(new Function<Observable<Integer>, Object>() {
              @Override
              public Object apply(Observable<Integer> o) throws Exception {
                  return o.flatMapIterable(new Function<Object, Iterable<Integer>>() {
                      @Override
                      public Iterable<Integer> apply(Object v) throws Exception {
                          return Arrays.asList(10, 20);
                      }
                  });
              }
          }, false, 1, 1, 10, 20);
      }
  
      @Test
      public void failingInnerCancelsSource() {
          final AtomicInteger counter = new AtomicInteger();
          Observable.range(1, 5)
          .doOnNext(new Consumer<Integer>() {
              @Override
              public void accept(Integer v) throws Exception {
                  counter.getAndIncrement();
              }
          })
          .flatMapIterable(new Function<Integer, Iterable<Integer>>() {
              @Override
              public Iterable<Integer> apply(Integer v)
                      throws Exception {
                  return new Iterable<Integer>() {
                      @Override
                      public Iterator<Integer> iterator() {
                          return new Iterator<Integer>() {
                              @Override
                              public boolean hasNext() {
                                  return true;
                              }
  
                              @Override
                              public Integer next() {
                                  throw new TestException();
                              }
  
                              @Override
                              public void remove() {
                                  throw new UnsupportedOperationException();
                              }
                          };
                      }
                  };
              }
          })
          .test()
          .assertFailure(TestException.class);
  
          assertEquals(1, counter.get());
      }
  
      @Test
      public void doubleOnSubscribe() {
          TestHelper.checkDoubleOnSubscribeObservable(o -> o.flatMapIterable(v -> Collections.singletonList(v)));
      }
  }
  