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.subjects;
  
  import static org.junit.Assert.*;
  import static org.mockito.ArgumentMatchers.any;
  import static org.mockito.Mockito.*;
  
  import java.util.List;
  import java.util.concurrent.*;
  import java.util.concurrent.atomic.AtomicReference;
  
  import org.junit.*;
  import org.mockito.*;
  
  import io.reactivex.rxjava3.core.*;
  import io.reactivex.rxjava3.disposables.*;
  import io.reactivex.rxjava3.exceptions.TestException;
  import io.reactivex.rxjava3.functions.Function;
  import io.reactivex.rxjava3.observers.*;
  import io.reactivex.rxjava3.plugins.RxJavaPlugins;
  import io.reactivex.rxjava3.schedulers.Schedulers;
  import io.reactivex.rxjava3.subjects.BehaviorSubject.BehaviorDisposable;
  import io.reactivex.rxjava3.testsupport.TestHelper;
  
  public class BehaviorSubjectTest extends SubjectTest<Integer> {
  
      private final Throwable testException = new Throwable();
  
      @Override
      protected Subject<Integer> create() {
          return BehaviorSubject.create();
      }
  
      @Test
      public void thatSubscriberReceivesDefaultValueAndSubsequentEvents() {
          BehaviorSubject<String> subject = BehaviorSubject.createDefault("default");
  
          Observer<String> observer = TestHelper.mockObserver();
          subject.subscribe(observer);
  
          subject.onNext("one");
          subject.onNext("two");
          subject.onNext("three");
  
          verify(observer, times(1)).onNext("default");
          verify(observer, times(1)).onNext("one");
          verify(observer, times(1)).onNext("two");
          verify(observer, times(1)).onNext("three");
          verify(observer, Mockito.never()).onError(testException);
          verify(observer, Mockito.never()).onComplete();
      }
  
      @Test
      public void thatSubscriberReceivesLatestAndThenSubsequentEvents() {
          BehaviorSubject<String> subject = BehaviorSubject.createDefault("default");
  
          subject.onNext("one");
  
          Observer<String> observer = TestHelper.mockObserver();
          subject.subscribe(observer);
  
          subject.onNext("two");
          subject.onNext("three");
  
          verify(observer, Mockito.never()).onNext("default");
          verify(observer, times(1)).onNext("one");
          verify(observer, times(1)).onNext("two");
          verify(observer, times(1)).onNext("three");
          verify(observer, Mockito.never()).onError(testException);
          verify(observer, Mockito.never()).onComplete();
      }
  
      @Test
      public void subscribeThenOnComplete() {
          BehaviorSubject<String> subject = BehaviorSubject.createDefault("default");
  
          Observer<String> observer = TestHelper.mockObserver();
          subject.subscribe(observer);
  
          subject.onNext("one");
          subject.onComplete();
  
          verify(observer, times(1)).onNext("default");
          verify(observer, times(1)).onNext("one");
          verify(observer, Mockito.never()).onError(any(Throwable.class));
          verify(observer, times(1)).onComplete();
      }
  
      @Test
      public void subscribeToCompletedOnlyEmitsOnComplete() {
          BehaviorSubject<String> subject = BehaviorSubject.createDefault("default");
          subject.onNext("one");
          subject.onComplete();
  
          Observer<String> observer = TestHelper.mockObserver();
          subject.subscribe(observer);
  
          verify(observer, never()).onNext("default");
          verify(observer, never()).onNext("one");
          verify(observer, Mockito.never()).onError(any(Throwable.class));
          verify(observer, times(1)).onComplete();
      }
  
      @Test
      public void subscribeToErrorOnlyEmitsOnError() {
          BehaviorSubject<String> subject = BehaviorSubject.createDefault("default");
          subject.onNext("one");
          RuntimeException re = new RuntimeException("test error");
          subject.onError(re);
  
          Observer<String> observer = TestHelper.mockObserver();
          subject.subscribe(observer);
  
          verify(observer, never()).onNext("default");
          verify(observer, never()).onNext("one");
          verify(observer, times(1)).onError(re);
          verify(observer, never()).onComplete();
      }
  
      @Test
      public void completedStopsEmittingData() {
          BehaviorSubject<Integer> channel = BehaviorSubject.createDefault(2013);
          Observer<Object> observerA = TestHelper.mockObserver();
          Observer<Object> observerB = TestHelper.mockObserver();
          Observer<Object> observerC = TestHelper.mockObserver();
  
          TestObserver<Object> to = new TestObserver<>(observerA);
  
          channel.subscribe(to);
          channel.subscribe(observerB);
  
          InOrder inOrderA = inOrder(observerA);
          InOrder inOrderB = inOrder(observerB);
          InOrder inOrderC = inOrder(observerC);
  
          inOrderA.verify(observerA).onNext(2013);
          inOrderB.verify(observerB).onNext(2013);
  
          channel.onNext(42);
  
          inOrderA.verify(observerA).onNext(42);
          inOrderB.verify(observerB).onNext(42);
  
          to.dispose();
          inOrderA.verifyNoMoreInteractions();
  
          channel.onNext(4711);
  
          inOrderB.verify(observerB).onNext(4711);
  
          channel.onComplete();
  
          inOrderB.verify(observerB).onComplete();
  
          channel.subscribe(observerC);
  
          inOrderC.verify(observerC).onComplete();
  
          channel.onNext(13);
  
          inOrderB.verifyNoMoreInteractions();
          inOrderC.verifyNoMoreInteractions();
      }
  
      @Test
      public void completedAfterErrorIsNotSent() {
          BehaviorSubject<String> subject = BehaviorSubject.createDefault("default");
  
          Observer<String> observer = TestHelper.mockObserver();
          subject.subscribe(observer);
  
          subject.onNext("one");
          subject.onError(testException);
          subject.onNext("two");
          subject.onComplete();
  
          verify(observer, times(1)).onNext("default");
          verify(observer, times(1)).onNext("one");
          verify(observer, times(1)).onError(testException);
          verify(observer, never()).onNext("two");
          verify(observer, never()).onComplete();
      }
  
      @Test
      public void completedAfterErrorIsNotSent2() {
          BehaviorSubject<String> subject = BehaviorSubject.createDefault("default");
  
          Observer<String> observer = TestHelper.mockObserver();
          subject.subscribe(observer);
  
          subject.onNext("one");
          subject.onError(testException);
          subject.onNext("two");
          subject.onComplete();
  
          verify(observer, times(1)).onNext("default");
          verify(observer, times(1)).onNext("one");
          verify(observer, times(1)).onError(testException);
          verify(observer, never()).onNext("two");
          verify(observer, never()).onComplete();
  
          Observer<Object> o2 = TestHelper.mockObserver();
          subject.subscribe(o2);
          verify(o2, times(1)).onError(testException);
          verify(o2, never()).onNext(any());
          verify(o2, never()).onComplete();
      }
  
      @Test
      public void completedAfterErrorIsNotSent3() {
          BehaviorSubject<String> subject = BehaviorSubject.createDefault("default");
  
          Observer<String> observer = TestHelper.mockObserver();
          subject.subscribe(observer);
  
          subject.onNext("one");
          subject.onComplete();
          subject.onNext("two");
          subject.onComplete();
  
          verify(observer, times(1)).onNext("default");
          verify(observer, times(1)).onNext("one");
          verify(observer, times(1)).onComplete();
          verify(observer, never()).onError(any(Throwable.class));
          verify(observer, never()).onNext("two");
  
          Observer<Object> o2 = TestHelper.mockObserver();
          subject.subscribe(o2);
          verify(o2, times(1)).onComplete();
          verify(o2, never()).onNext(any());
          verify(observer, never()).onError(any(Throwable.class));
      }
  
      @Test
      public void unsubscriptionCase() {
          BehaviorSubject<String> src = BehaviorSubject.createDefault("null"); // FIXME was plain null which is not allowed
  
          for (int i = 0; i < 10; i++) {
              final Observer<Object> o = TestHelper.mockObserver();
              InOrder inOrder = inOrder(o);
              String v = "" + i;
              src.onNext(v);
              System.out.printf("Turn: %d%n", i);
              src.firstElement()
                  .toObservable()
                  .flatMap(new Function<String, Observable<String>>() {
  
                      @Override
                      public Observable<String> apply(String t1) {
                          return Observable.just(t1 + ", " + t1);
                      }
                  })
                  .subscribe(new DefaultObserver<String>() {
                      @Override
                      public void onNext(String t) {
                          o.onNext(t);
                      }
  
                      @Override
                      public void onError(Throwable e) {
                          o.onError(e);
                      }
  
                      @Override
                      public void onComplete() {
                          o.onComplete();
                      }
                  });
              inOrder.verify(o).onNext(v + ", " + v);
              inOrder.verify(o).onComplete();
              verify(o, never()).onError(any(Throwable.class));
          }
      }
  
      @Test
      public void startEmpty() {
          BehaviorSubject<Integer> source = BehaviorSubject.create();
          final Observer<Object> o = TestHelper.mockObserver();
          InOrder inOrder = inOrder(o);
  
          source.subscribe(o);
  
          inOrder.verify(o, never()).onNext(any());
          inOrder.verify(o, never()).onComplete();
  
          source.onNext(1);
  
          source.onComplete();
  
          source.onNext(2);
  
          verify(o, never()).onError(any(Throwable.class));
  
          inOrder.verify(o).onNext(1);
          inOrder.verify(o).onComplete();
          inOrder.verifyNoMoreInteractions();
      }
  
      @Test
      public void startEmptyThenAddOne() {
          BehaviorSubject<Integer> source = BehaviorSubject.create();
          final Observer<Object> o = TestHelper.mockObserver();
          InOrder inOrder = inOrder(o);
  
          source.onNext(1);
  
          source.subscribe(o);
  
          inOrder.verify(o).onNext(1);
  
          source.onComplete();
  
          source.onNext(2);
  
          inOrder.verify(o).onComplete();
          inOrder.verifyNoMoreInteractions();
  
          verify(o, never()).onError(any(Throwable.class));
  
      }
  
      @Test
      public void startEmptyCompleteWithOne() {
          BehaviorSubject<Integer> source = BehaviorSubject.create();
          final Observer<Object> o = TestHelper.mockObserver();
  
          source.onNext(1);
          source.onComplete();
  
          source.onNext(2);
  
          source.subscribe(o);
  
          verify(o).onComplete();
          verify(o, never()).onError(any(Throwable.class));
          verify(o, never()).onNext(any());
      }
  
      @Test
      public void takeOneSubscriber() {
          BehaviorSubject<Integer> source = BehaviorSubject.createDefault(1);
          final Observer<Object> o = TestHelper.mockObserver();
  
          source.take(1).subscribe(o);
  
          verify(o).onNext(1);
          verify(o).onComplete();
          verify(o, never()).onError(any(Throwable.class));
  
          assertEquals(0, source.subscriberCount());
          assertFalse(source.hasObservers());
      }
  
      @Test
      public void emissionSubscriptionRace() throws Exception {
          Scheduler s = Schedulers.io();
          Scheduler.Worker worker = Schedulers.io().createWorker();
          try {
              for (int i = 0; i < 50000; i++) {
                  if (i % 1000 == 0) {
                      System.out.println(i);
                  }
                  final BehaviorSubject<Object> rs = BehaviorSubject.create();
  
                  final CountDownLatch finish = new CountDownLatch(1);
                  final CountDownLatch start = new CountDownLatch(1);
  
                  worker.schedule(new Runnable() {
                      @Override
                      public void run() {
                          try {
                              start.await();
                          } catch (Exception e1) {
                              e1.printStackTrace();
                          }
                          rs.onNext(1);
                      }
                  });
  
                  final AtomicReference<Object> o = new AtomicReference<>();
  
                  rs.subscribeOn(s).observeOn(Schedulers.io())
                  .subscribe(new DefaultObserver<Object>() {
  
                      @Override
                      public void onComplete() {
                          o.set(-1);
                          finish.countDown();
                      }
  
                      @Override
                      public void onError(Throwable e) {
                          o.set(e);
                          finish.countDown();
                      }
  
                      @Override
                      public void onNext(Object t) {
                          o.set(t);
                          finish.countDown();
                      }
  
                  });
                  start.countDown();
  
                  if (!finish.await(5, TimeUnit.SECONDS)) {
                      System.out.println(o.get());
                      System.out.println(rs.hasObservers());
                      rs.onComplete();
                      Assert.fail("Timeout @ " + i);
                      break;
                  } else {
                      Assert.assertEquals(1, o.get());
                      worker.schedule(new Runnable() {
                          @Override
                          public void run() {
                              rs.onComplete();
                          }
                      });
                  }
              }
          } finally {
              worker.dispose();
          }
      }
  
      @Test
      public void currentStateMethodsNormalEmptyStart() {
          BehaviorSubject<Object> as = BehaviorSubject.create();
  
          assertFalse(as.hasValue());
          assertFalse(as.hasThrowable());
          assertFalse(as.hasComplete());
          assertNull(as.getValue());
          assertNull(as.getThrowable());
  
          as.onNext(1);
  
          assertTrue(as.hasValue());
          assertFalse(as.hasThrowable());
          assertFalse(as.hasComplete());
          assertEquals(1, as.getValue());
          assertNull(as.getThrowable());
  
          as.onComplete();
  
          assertFalse(as.hasValue());
          assertFalse(as.hasThrowable());
          assertTrue(as.hasComplete());
          assertNull(as.getValue());
          assertNull(as.getThrowable());
      }
  
      @Test
      public void currentStateMethodsNormalSomeStart() {
          BehaviorSubject<Object> as = BehaviorSubject.createDefault((Object)1);
  
          assertTrue(as.hasValue());
          assertFalse(as.hasThrowable());
          assertFalse(as.hasComplete());
          assertEquals(1, as.getValue());
          assertNull(as.getThrowable());
  
          as.onNext(2);
  
          assertTrue(as.hasValue());
          assertFalse(as.hasThrowable());
          assertFalse(as.hasComplete());
          assertEquals(2, as.getValue());
          assertNull(as.getThrowable());
  
          as.onComplete();
          assertFalse(as.hasValue());
          assertFalse(as.hasThrowable());
          assertTrue(as.hasComplete());
          assertNull(as.getValue());
          assertNull(as.getThrowable());
      }
  
      @Test
      public void currentStateMethodsEmpty() {
          BehaviorSubject<Object> as = BehaviorSubject.create();
  
          assertFalse(as.hasValue());
          assertFalse(as.hasThrowable());
          assertFalse(as.hasComplete());
          assertNull(as.getValue());
          assertNull(as.getThrowable());
  
          as.onComplete();
  
          assertFalse(as.hasValue());
          assertFalse(as.hasThrowable());
          assertTrue(as.hasComplete());
          assertNull(as.getValue());
          assertNull(as.getThrowable());
      }
  
      @Test
      public void currentStateMethodsError() {
          BehaviorSubject<Object> as = BehaviorSubject.create();
  
          assertFalse(as.hasValue());
          assertFalse(as.hasThrowable());
          assertFalse(as.hasComplete());
          assertNull(as.getValue());
          assertNull(as.getThrowable());
  
          as.onError(new TestException());
  
          assertFalse(as.hasValue());
          assertTrue(as.hasThrowable());
          assertFalse(as.hasComplete());
          assertNull(as.getValue());
          assertTrue(as.getThrowable() instanceof TestException);
      }
  
      @Test
      public void cancelOnArrival() {
          BehaviorSubject<Object> p = BehaviorSubject.create();
  
          assertFalse(p.hasObservers());
  
          p.test(true).assertEmpty();
  
          assertFalse(p.hasObservers());
      }
  
      @Test
      public void onSubscribe() {
          BehaviorSubject<Object> p = BehaviorSubject.create();
  
          Disposable bs = Disposable.empty();
  
          p.onSubscribe(bs);
  
          assertFalse(bs.isDisposed());
  
          p.onComplete();
  
          bs = Disposable.empty();
  
          p.onSubscribe(bs);
  
          assertTrue(bs.isDisposed());
      }
  
      @Test
      public void onErrorAfterComplete() {
          BehaviorSubject<Object> p = BehaviorSubject.create();
  
          p.onComplete();
  
          List<Throwable> errors = TestHelper.trackPluginErrors();
          try {
              p.onError(new TestException());
  
              TestHelper.assertUndeliverable(errors, 0, TestException.class);
          } finally {
              RxJavaPlugins.reset();
          }
      }
  
      @Test
      public void cancelOnArrival2() {
          BehaviorSubject<Object> p = BehaviorSubject.create();
  
          TestObserver<Object> to = p.test();
  
          p.test(true).assertEmpty();
  
          p.onNext(1);
          p.onComplete();
  
          to.assertResult(1);
      }
  
      @Test
      public void addRemoveRace() {
          for (int i = 0; i < TestHelper.RACE_DEFAULT_LOOPS; i++) {
              final BehaviorSubject<Object> p = BehaviorSubject.create();
  
              final TestObserver<Object> to = p.test();
  
              Runnable r1 = new Runnable() {
                  @Override
                  public void run() {
                      p.test();
                  }
              };
  
              Runnable r2 = new Runnable() {
                  @Override
                  public void run() {
                      to.dispose();
                  }
              };
  
              TestHelper.race(r1, r2);
          }
      }
  
      @SuppressWarnings({ "rawtypes", "unchecked" })
      @Test
      public void subscribeOnNextRace() {
          for (int i = 0; i < TestHelper.RACE_DEFAULT_LOOPS; i++) {
              final BehaviorSubject<Object> p = BehaviorSubject.createDefault((Object)1);
  
              final TestObserver[] to = { null };
  
              Runnable r1 = new Runnable() {
                  @Override
                  public void run() {
                      to[0] = p.test();
                  }
              };
  
              Runnable r2 = new Runnable() {
                  @Override
                  public void run() {
                      p.onNext(2);
                  }
              };
  
              TestHelper.race(r1, r2);
  
              if (to[0].values().size() == 1) {
                  to[0].assertValue(2).assertNoErrors().assertNotComplete();
              } else {
                  to[0].assertValues(1, 2).assertNoErrors().assertNotComplete();
              }
          }
      }
  
      @Test
      public void innerDisposed() {
          BehaviorSubject.create()
          .subscribe(new Observer<Object>() {
              @Override
              public void onSubscribe(Disposable d) {
                  assertFalse(d.isDisposed());
  
                  d.dispose();
  
                  assertTrue(d.isDisposed());
              }
  
              @Override
              public void onNext(Object value) {
  
              }
  
              @Override
              public void onError(Throwable e) {
  
              }
  
              @Override
              public void onComplete() {
  
              }
          });
      }
  
      @Test
      public void completeSubscribeRace() throws Exception {
          for (int i = 0; i < TestHelper.RACE_DEFAULT_LOOPS; i++) {
              final BehaviorSubject<Object> p = BehaviorSubject.create();
  
              final TestObserver<Object> to = new TestObserver<>();
  
              Runnable r1 = new Runnable() {
                  @Override
                  public void run() {
                      p.subscribe(to);
                  }
              };
  
              Runnable r2 = new Runnable() {
                  @Override
                  public void run() {
                      p.onComplete();
                  }
              };
  
              TestHelper.race(r1, r2);
  
              to.assertResult();
          }
      }
  
      @Test
      public void errorSubscribeRace() throws Exception {
          for (int i = 0; i < TestHelper.RACE_DEFAULT_LOOPS; i++) {
              final BehaviorSubject<Object> p = BehaviorSubject.create();
  
              final TestObserver<Object> to = new TestObserver<>();
  
              final TestException ex = new TestException();
  
              Runnable r1 = new Runnable() {
                  @Override
                  public void run() {
                      p.subscribe(to);
                  }
              };
  
              Runnable r2 = new Runnable() {
                  @Override
                  public void run() {
                      p.onError(ex);
                  }
              };
  
              TestHelper.race(r1, r2);
  
              to.assertFailure(TestException.class);
          }
      }
  
      @Test
      public void behaviorDisposableDisposeState() {
          BehaviorSubject<Integer> bs = BehaviorSubject.create();
          bs.onNext(1);
  
          TestObserver<Integer> to = new TestObserver<>();
  
          BehaviorDisposable<Integer> bd = new BehaviorDisposable<>(to, bs);
          to.onSubscribe(bd);
  
          assertFalse(bd.isDisposed());
  
          bd.dispose();
  
          assertTrue(bd.isDisposed());
  
          bd.dispose();
  
          assertTrue(bd.isDisposed());
  
          assertTrue(bd.test(2));
  
          bd.emitFirst();
  
          to.assertEmpty();
  
          bd.emitNext(2, 0);
      }
  
      @Test
      public void emitFirstDisposeRace() {
          for (int i = 0; i < TestHelper.RACE_LONG_LOOPS; i++) {
  
              BehaviorSubject<Integer> bs = BehaviorSubject.create();
              bs.onNext(1);
  
              TestObserver<Integer> to = new TestObserver<>();
  
              final BehaviorDisposable<Integer> bd = new BehaviorDisposable<>(to, bs);
              to.onSubscribe(bd);
  
              Runnable r1 = new Runnable() {
                  @Override
                  public void run() {
                      bd.emitFirst();
                  }
              };
              Runnable r2 = new Runnable() {
                  @Override
                  public void run() {
                      bd.dispose();
                  }
              };
  
              TestHelper.race(r1, r2);
          }
      }
  
      @Test
      public void emitNextDisposeRace() {
          for (int i = 0; i < TestHelper.RACE_LONG_LOOPS; i++) {
  
              BehaviorSubject<Integer> bs = BehaviorSubject.create();
              bs.onNext(1);
  
              TestObserver<Integer> to = new TestObserver<>();
  
              final BehaviorDisposable<Integer> bd = new BehaviorDisposable<>(to, bs);
              to.onSubscribe(bd);
  
              Runnable r1 = new Runnable() {
                  @Override
                  public void run() {
                      bd.emitNext(2, 0);
                  }
              };
              Runnable r2 = new Runnable() {
                  @Override
                  public void run() {
                      bd.dispose();
                  }
              };
  
              TestHelper.race(r1, r2);
          }
      }
  
      @Test
      public void emittingEmitNext() {
          BehaviorSubject<Integer> bs = BehaviorSubject.create();
          bs.onNext(1);
  
          TestObserver<Integer> to = new TestObserver<>();
  
          final BehaviorDisposable<Integer> bd = new BehaviorDisposable<>(to, bs);
          to.onSubscribe(bd);
  
          bd.emitting = true;
          bd.emitNext(2, 1);
          bd.emitNext(3, 2);
  
          assertNotNull(bd.queue);
      }
  
      @Test
      public void hasObservers() {
          BehaviorSubject<Integer> bs = BehaviorSubject.create();
  
          assertFalse(bs.hasObservers());
  
          TestObserver<Integer> to = bs.test();
  
          assertTrue(bs.hasObservers());
  
          to.dispose();
  
          assertFalse(bs.hasObservers());
      }
  }
  