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.fail;
  import static org.mockito.ArgumentMatchers.any;
  import static org.mockito.Mockito.*;
  
  import org.junit.Test;
  
  import io.reactivex.rxjava3.core.*;
  import io.reactivex.rxjava3.disposables.*;
  import io.reactivex.rxjava3.exceptions.TestException;
  import io.reactivex.rxjava3.functions.*;
  import io.reactivex.rxjava3.internal.functions.Functions;
  import io.reactivex.rxjava3.observers.TestObserver;
  import io.reactivex.rxjava3.subjects.*;
  import io.reactivex.rxjava3.testsupport.*;
  
  public class ObservableTakeWhileTest extends RxJavaTest {
  
      @Test
      public void takeWhile1() {
          Observable<Integer> w = Observable.just(1, 2, 3);
          Observable<Integer> take = w.takeWhile(new Predicate<Integer>() {
              @Override
              public boolean test(Integer input) {
                  return input < 3;
              }
          });
  
          Observer<Integer> observer = TestHelper.mockObserver();
          take.subscribe(observer);
          verify(observer, times(1)).onNext(1);
          verify(observer, times(1)).onNext(2);
          verify(observer, never()).onNext(3);
          verify(observer, never()).onError(any(Throwable.class));
          verify(observer, times(1)).onComplete();
      }
  
      @Test
      public void takeWhileOnSubject1() {
          Subject<Integer> s = PublishSubject.create();
          Observable<Integer> take = s.takeWhile(new Predicate<Integer>() {
              @Override
              public boolean test(Integer input) {
                  return input < 3;
              }
          });
  
          Observer<Integer> observer = TestHelper.mockObserver();
          take.subscribe(observer);
  
          s.onNext(1);
          s.onNext(2);
          s.onNext(3);
          s.onNext(4);
          s.onNext(5);
          s.onComplete();
  
          verify(observer, times(1)).onNext(1);
          verify(observer, times(1)).onNext(2);
          verify(observer, never()).onNext(3);
          verify(observer, never()).onNext(4);
          verify(observer, never()).onNext(5);
          verify(observer, never()).onError(any(Throwable.class));
          verify(observer, times(1)).onComplete();
      }
  
      @Test
      public void takeWhile2() {
          Observable<String> w = Observable.just("one", "two", "three");
          Observable<String> take = w.takeWhile(new Predicate<String>() {
              int index;
  
              @Override
              public boolean test(String input) {
                  return index++ < 2;
              }
          });
  
          Observer<String> observer = TestHelper.mockObserver();
          take.subscribe(observer);
          verify(observer, times(1)).onNext("one");
          verify(observer, times(1)).onNext("two");
          verify(observer, never()).onNext("three");
          verify(observer, never()).onError(any(Throwable.class));
          verify(observer, times(1)).onComplete();
      }
  
      @Test
      @SuppressUndeliverable
      public void takeWhileDoesntLeakErrors() {
          Observable<String> source = Observable.unsafeCreate(new ObservableSource<String>() {
              @Override
              public void subscribe(Observer<? super String> observer) {
                  observer.onSubscribe(Disposable.empty());
                  observer.onNext("one");
                  observer.onError(new Throwable("test failed"));
              }
          });
  
          source.takeWhile(new Predicate<String>() {
              @Override
              public boolean test(String s) {
                  return false;
              }
          }).blockingLast("");
      }
  
      @Test
      public void takeWhileProtectsPredicateCall() {
          TestObservable source = new TestObservable(mock(Disposable.class), "one");
          final RuntimeException testException = new RuntimeException("test exception");
  
          Observer<String> observer = TestHelper.mockObserver();
          Observable<String> take = Observable.unsafeCreate(source)
                  .takeWhile(new Predicate<String>() {
              @Override
              public boolean test(String s) {
                  throw testException;
              }
          });
          take.subscribe(observer);
  
          // wait for the Observable to complete
          try {
              source.t.join();
          } catch (Throwable e) {
              e.printStackTrace();
              fail(e.getMessage());
          }
  
          verify(observer, never()).onNext(any(String.class));
          verify(observer, times(1)).onError(testException);
      }
  
      @Test
      public void unsubscribeAfterTake() {
          Disposable upstream = mock(Disposable.class);
          TestObservable w = new TestObservable(upstream, "one", "two", "three");
  
          Observer<String> observer = TestHelper.mockObserver();
          Observable<String> take = Observable.unsafeCreate(w)
                  .takeWhile(new Predicate<String>() {
              int index;
  
              @Override
              public boolean test(String s) {
                  return index++ < 1;
              }
          });
          take.subscribe(observer);
  
          // wait for the Observable to complete
          try {
              w.t.join();
          } catch (Throwable e) {
              e.printStackTrace();
              fail(e.getMessage());
          }
  
          System.out.println("TestObservable thread finished");
          verify(observer, times(1)).onNext("one");
          verify(observer, never()).onNext("two");
          verify(observer, never()).onNext("three");
          verify(upstream, times(1)).dispose();
      }
  
      private static class TestObservable implements ObservableSource<String> {
  
          final Disposable upstream;
          final String[] values;
          Thread t;
  
          TestObservable(Disposable upstream, String... values) {
              this.upstream = upstream;
              this.values = values;
          }
  
          @Override
          public void subscribe(final Observer<? super String> observer) {
              System.out.println("TestObservable subscribed to ...");
              observer.onSubscribe(upstream);
              t = new Thread(new Runnable() {
  
                  @Override
                  public void run() {
                      try {
                          System.out.println("running TestObservable thread");
                          for (String s : values) {
                              System.out.println("TestObservable onNext: " + s);
                              observer.onNext(s);
                          }
                          observer.onComplete();
                      } catch (Throwable e) {
                          throw new RuntimeException(e);
                      }
                  }
  
              });
              System.out.println("starting TestObservable thread");
              t.start();
              System.out.println("done starting TestObservable thread");
          }
      }
  
      @Test
      public void noUnsubscribeDownstream() {
          Observable<Integer> source = Observable.range(1, 1000).takeWhile(new Predicate<Integer>() {
              @Override
              public boolean test(Integer t1) {
                  return t1 < 2;
              }
          });
          TestObserver<Integer> to = new TestObserver<>();
  
          source.subscribe(to);
  
          to.assertNoErrors();
          to.assertValue(1);
  
          // 2.0.2 - not anymore
  //        Assert.assertTrue("Not cancelled!", ts.isCancelled());
      }
  
      @Test
      public void errorCauseIncludesLastValue() {
          TestObserverEx<String> to = new TestObserverEx<>();
          Observable.just("abc").takeWhile(new Predicate<String>() {
              @Override
              public boolean test(String t1) {
                  throw new TestException();
              }
          }).subscribe(to);
  
          to.assertTerminated();
          to.assertNoValues();
          to.assertError(TestException.class);
          // FIXME last cause value not recorded
  //        assertTrue(ts.getOnErrorEvents().get(0).getCause().getMessage().contains("abc"));
      }
  
      @Test
      public void dispose() {
          TestHelper.checkDisposed(PublishSubject.create().takeWhile(Functions.alwaysTrue()));
      }
  
      @Test
      public void doubleOnSubscribe() {
          TestHelper.checkDoubleOnSubscribeObservable(new Function<Observable<Object>, ObservableSource<Object>>() {
              @Override
              public ObservableSource<Object> apply(Observable<Object> o) throws Exception {
                  return o.takeWhile(Functions.alwaysTrue());
              }
          });
      }
  
      @Test
      public void badSource() {
          new Observable<Integer>() {
              @Override
              protected void subscribeActual(Observer<? super Integer> observer) {
                  observer.onSubscribe(Disposable.empty());
                  observer.onComplete();
                  observer.onComplete();
              }
          }
          .takeWhile(Functions.alwaysTrue())
          .test()
          .assertResult();
      }
  }
  