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.flowable;
  
  import static org.junit.Assert.assertFalse;
  import static org.mockito.ArgumentMatchers.any;
  import static org.mockito.Mockito.*;
  
  import java.util.concurrent.TimeUnit;
  
  import org.junit.*;
  import org.mockito.InOrder;
  import org.reactivestreams.*;
  
  import io.reactivex.rxjava3.core.*;
  import io.reactivex.rxjava3.exceptions.*;
  import io.reactivex.rxjava3.functions.Function;
  import io.reactivex.rxjava3.internal.subscriptions.BooleanSubscription;
  import io.reactivex.rxjava3.processors.*;
  import io.reactivex.rxjava3.schedulers.*;
  import io.reactivex.rxjava3.subscribers.TestSubscriber;
  import io.reactivex.rxjava3.testsupport.TestHelper;
  
  public class FlowableSampleTest extends RxJavaTest {
      private TestScheduler scheduler;
      private Scheduler.Worker innerScheduler;
      private Subscriber<Long> subscriber;
      private Subscriber<Object> subscriber2;
  
      @Before
      // due to mocking
      public void before() {
          scheduler = new TestScheduler();
          innerScheduler = scheduler.createWorker();
          subscriber = TestHelper.mockSubscriber();
          subscriber2 = TestHelper.mockSubscriber();
      }
  
      @Test
      public void sample() {
          Flowable<Long> source = Flowable.unsafeCreate(new Publisher<Long>() {
              @Override
              public void subscribe(final Subscriber<? super Long> subscriber1) {
                  subscriber1.onSubscribe(new BooleanSubscription());
                  innerScheduler.schedule(new Runnable() {
                      @Override
                      public void run() {
                          subscriber1.onNext(1L);
                      }
                  }, 1, TimeUnit.SECONDS);
                  innerScheduler.schedule(new Runnable() {
                      @Override
                      public void run() {
                          subscriber1.onNext(2L);
                      }
                  }, 2, TimeUnit.SECONDS);
                  innerScheduler.schedule(new Runnable() {
                      @Override
                      public void run() {
                          subscriber1.onComplete();
                      }
                  }, 3, TimeUnit.SECONDS);
              }
          });
  
          Flowable<Long> sampled = source.sample(400L, TimeUnit.MILLISECONDS, scheduler);
          sampled.subscribe(subscriber);
  
          InOrder inOrder = inOrder(subscriber);
  
          scheduler.advanceTimeTo(800L, TimeUnit.MILLISECONDS);
          verify(subscriber, never()).onNext(any(Long.class));
          verify(subscriber, never()).onComplete();
          verify(subscriber, never()).onError(any(Throwable.class));
  
          scheduler.advanceTimeTo(1200L, TimeUnit.MILLISECONDS);
          inOrder.verify(subscriber, times(1)).onNext(1L);
          verify(subscriber, never()).onNext(2L);
          verify(subscriber, never()).onComplete();
          verify(subscriber, never()).onError(any(Throwable.class));
  
          scheduler.advanceTimeTo(1600L, TimeUnit.MILLISECONDS);
          inOrder.verify(subscriber, never()).onNext(1L);
          verify(subscriber, never()).onNext(2L);
          verify(subscriber, never()).onComplete();
          verify(subscriber, never()).onError(any(Throwable.class));
  
          scheduler.advanceTimeTo(2000L, TimeUnit.MILLISECONDS);
          inOrder.verify(subscriber, never()).onNext(1L);
          inOrder.verify(subscriber, times(1)).onNext(2L);
          verify(subscriber, never()).onComplete();
          verify(subscriber, never()).onError(any(Throwable.class));
  
          scheduler.advanceTimeTo(3000L, TimeUnit.MILLISECONDS);
          inOrder.verify(subscriber, never()).onNext(1L);
          inOrder.verify(subscriber, never()).onNext(2L);
          verify(subscriber, times(1)).onComplete();
          verify(subscriber, never()).onError(any(Throwable.class));
      }
  
      @Test
      public void sampleWithSamplerNormal() {
          PublishProcessor<Integer> source = PublishProcessor.create();
          PublishProcessor<Integer> sampler = PublishProcessor.create();
  
          Flowable<Integer> m = source.sample(sampler);
          m.subscribe(subscriber2);
  
          source.onNext(1);
          source.onNext(2);
          sampler.onNext(1);
          source.onNext(3);
          source.onNext(4);
          sampler.onNext(2);
          source.onComplete();
          sampler.onNext(3);
  
          InOrder inOrder = inOrder(subscriber2);
          inOrder.verify(subscriber2, never()).onNext(1);
          inOrder.verify(subscriber2, times(1)).onNext(2);
          inOrder.verify(subscriber2, never()).onNext(3);
          inOrder.verify(subscriber2, times(1)).onNext(4);
          inOrder.verify(subscriber2, times(1)).onComplete();
          verify(subscriber, never()).onError(any(Throwable.class));
      }
  
      @Test
      public void sampleWithSamplerNoDuplicates() {
          PublishProcessor<Integer> source = PublishProcessor.create();
          PublishProcessor<Integer> sampler = PublishProcessor.create();
  
          Flowable<Integer> m = source.sample(sampler);
          m.subscribe(subscriber2);
  
          source.onNext(1);
          source.onNext(2);
          sampler.onNext(1);
          sampler.onNext(1);
  
          source.onNext(3);
          source.onNext(4);
          sampler.onNext(2);
          sampler.onNext(2);
  
          source.onComplete();
          sampler.onNext(3);
  
          InOrder inOrder = inOrder(subscriber2);
          inOrder.verify(subscriber2, never()).onNext(1);
          inOrder.verify(subscriber2, times(1)).onNext(2);
          inOrder.verify(subscriber2, never()).onNext(3);
          inOrder.verify(subscriber2, times(1)).onNext(4);
          inOrder.verify(subscriber2, times(1)).onComplete();
          verify(subscriber, never()).onError(any(Throwable.class));
      }
  
      @Test
      public void sampleWithSamplerTerminatingEarly() {
          PublishProcessor<Integer> source = PublishProcessor.create();
          PublishProcessor<Integer> sampler = PublishProcessor.create();
  
          Flowable<Integer> m = source.sample(sampler);
          m.subscribe(subscriber2);
  
          source.onNext(1);
          source.onNext(2);
          sampler.onNext(1);
          sampler.onComplete();
  
          source.onNext(3);
          source.onNext(4);
  
          InOrder inOrder = inOrder(subscriber2);
          inOrder.verify(subscriber2, never()).onNext(1);
          inOrder.verify(subscriber2, times(1)).onNext(2);
          inOrder.verify(subscriber2, times(1)).onComplete();
          inOrder.verify(subscriber2, never()).onNext(any());
          verify(subscriber, never()).onError(any(Throwable.class));
      }
  
      @Test
      public void sampleWithSamplerEmitAndTerminate() {
          PublishProcessor<Integer> source = PublishProcessor.create();
          PublishProcessor<Integer> sampler = PublishProcessor.create();
  
          Flowable<Integer> m = source.sample(sampler);
          m.subscribe(subscriber2);
  
          source.onNext(1);
          source.onNext(2);
          sampler.onNext(1);
          source.onNext(3);
          source.onComplete();
          sampler.onNext(2);
          sampler.onComplete();
  
          InOrder inOrder = inOrder(subscriber2);
          inOrder.verify(subscriber2, never()).onNext(1);
          inOrder.verify(subscriber2, times(1)).onNext(2);
          inOrder.verify(subscriber2, never()).onNext(3);
          inOrder.verify(subscriber2, times(1)).onComplete();
          inOrder.verify(subscriber2, never()).onNext(any());
          verify(subscriber, never()).onError(any(Throwable.class));
      }
  
      @Test
      public void sampleWithSamplerEmptySource() {
          PublishProcessor<Integer> source = PublishProcessor.create();
          PublishProcessor<Integer> sampler = PublishProcessor.create();
  
          Flowable<Integer> m = source.sample(sampler);
          m.subscribe(subscriber2);
  
          source.onComplete();
          sampler.onNext(1);
  
          InOrder inOrder = inOrder(subscriber2);
          inOrder.verify(subscriber2, times(1)).onComplete();
          verify(subscriber2, never()).onNext(any());
          verify(subscriber, never()).onError(any(Throwable.class));
      }
  
      @Test
      public void sampleWithSamplerSourceThrows() {
          PublishProcessor<Integer> source = PublishProcessor.create();
          PublishProcessor<Integer> sampler = PublishProcessor.create();
  
          Flowable<Integer> m = source.sample(sampler);
          m.subscribe(subscriber2);
  
          source.onNext(1);
          source.onError(new RuntimeException("Forced failure!"));
          sampler.onNext(1);
  
          InOrder inOrder = inOrder(subscriber2);
          inOrder.verify(subscriber2, times(1)).onError(any(Throwable.class));
          verify(subscriber2, never()).onNext(any());
          verify(subscriber, never()).onComplete();
      }
  
      @Test
      public void sampleWithSamplerThrows() {
          PublishProcessor<Integer> source = PublishProcessor.create();
          PublishProcessor<Integer> sampler = PublishProcessor.create();
  
          Flowable<Integer> m = source.sample(sampler);
          m.subscribe(subscriber2);
  
          source.onNext(1);
          sampler.onNext(1);
          sampler.onError(new RuntimeException("Forced failure!"));
  
          InOrder inOrder = inOrder(subscriber2);
          inOrder.verify(subscriber2, times(1)).onNext(1);
          inOrder.verify(subscriber2, times(1)).onError(any(RuntimeException.class));
          verify(subscriber, never()).onComplete();
      }
  
      @Test
      public void sampleUnsubscribe() {
          final Subscription s = mock(Subscription.class);
          Flowable<Integer> f = Flowable.unsafeCreate(
                  new Publisher<Integer>() {
                      @Override
                      public void subscribe(Subscriber<? super Integer> subscriber) {
                          subscriber.onSubscribe(s);
                      }
                  }
          );
          f.throttleLast(1, TimeUnit.MILLISECONDS).subscribe().dispose();
          verify(s).cancel();
      }
  
      @Test
      public void dispose() {
          TestHelper.checkDisposed(PublishProcessor.create().sample(1, TimeUnit.SECONDS, new TestScheduler()));
  
          TestHelper.checkDisposed(PublishProcessor.create().sample(Flowable.never()));
      }
  
      @Test
      public void error() {
          Flowable.error(new TestException())
          .sample(1, TimeUnit.SECONDS)
          .test()
          .assertFailure(TestException.class);
      }
  
      @Test
      public void backpressureOverflow() {
          BehaviorProcessor.createDefault(1)
          .sample(1, TimeUnit.MILLISECONDS)
          .test(0L)
          .awaitDone(5, TimeUnit.SECONDS)
          .assertFailure(MissingBackpressureException.class);
      }
  
      @Test
      public void backpressureOverflowWithOtherPublisher() {
          PublishProcessor<Integer> pp1 = PublishProcessor.create();
          PublishProcessor<Integer> pp2 = PublishProcessor.create();
  
          TestSubscriber<Integer> ts =  pp1
          .sample(pp2)
          .test(0L);
  
          pp1.onNext(1);
          pp2.onNext(2);
  
          ts.assertFailure(MissingBackpressureException.class);
  
          assertFalse(pp1.hasSubscribers());
          assertFalse(pp2.hasSubscribers());
      }
  
      @Test
      public void emitLastTimed() {
          Flowable.just(1)
          .sample(1, TimeUnit.DAYS, true)
          .test()
          .assertResult(1);
      }
  
      @Test
      public void emitLastTimedEmpty() {
          Flowable.empty()
          .sample(1, TimeUnit.DAYS, true)
          .test()
          .assertResult();
      }
  
      @Test
      public void emitLastTimedCustomScheduler() {
          Flowable.just(1)
          .sample(1, TimeUnit.DAYS, Schedulers.single(), true)
          .test()
          .assertResult(1);
      }
  
      @Test
      public void emitLastTimedRunCompleteRace() {
          for (int i = 0; i < TestHelper.RACE_DEFAULT_LOOPS; i++) {
              final TestScheduler scheduler = new TestScheduler();
  
              final PublishProcessor<Integer> pp = PublishProcessor.create();
  
              TestSubscriber<Integer> ts = pp.sample(1, TimeUnit.SECONDS, scheduler, true)
              .test();
  
              pp.onNext(1);
  
              Runnable r1 = new Runnable() {
                  @Override
                  public void run() {
                      pp.onComplete();
                  }
              };
  
              Runnable r2 = new Runnable() {
                  @Override
                  public void run() {
                      scheduler.advanceTimeBy(1, TimeUnit.SECONDS);
                  }
              };
  
              TestHelper.race(r1, r2);
  
              ts.assertResult(1);
          }
      }
  
      @Test
      public void emitLastOther() {
          Flowable.just(1)
          .sample(Flowable.timer(1, TimeUnit.DAYS), true)
          .test()
          .assertResult(1);
      }
  
      @Test
      public void emitLastOtherEmpty() {
          Flowable.empty()
          .sample(Flowable.timer(1, TimeUnit.DAYS), true)
          .test()
          .assertResult();
      }
  
      @Test
      public void emitLastOtherRunCompleteRace() {
          for (int i = 0; i < TestHelper.RACE_DEFAULT_LOOPS; i++) {
              final PublishProcessor<Integer> pp = PublishProcessor.create();
              final PublishProcessor<Integer> sampler = PublishProcessor.create();
  
              TestSubscriber<Integer> ts = pp.sample(sampler, true)
              .test();
  
              pp.onNext(1);
  
              Runnable r1 = new Runnable() {
                  @Override
                  public void run() {
                      pp.onComplete();
                  }
              };
  
              Runnable r2 = new Runnable() {
                  @Override
                  public void run() {
                      sampler.onNext(1);
                  }
              };
  
              TestHelper.race(r1, r2);
  
              ts.assertResult(1);
          }
      }
  
      @Test
      public void emitLastOtherCompleteCompleteRace() {
          for (int i = 0; i < TestHelper.RACE_DEFAULT_LOOPS; i++) {
              final PublishProcessor<Integer> pp = PublishProcessor.create();
              final PublishProcessor<Integer> sampler = PublishProcessor.create();
  
              TestSubscriber<Integer> ts = pp.sample(sampler, true).test();
  
              pp.onNext(1);
  
              Runnable r1 = new Runnable() {
                  @Override
                  public void run() {
                      pp.onComplete();
                  }
              };
  
              Runnable r2 = new Runnable() {
                  @Override
                  public void run() {
                      sampler.onComplete();
                  }
              };
  
              TestHelper.race(r1, r2);
  
              ts.assertResult(1);
          }
      }
  
      @Test
      public void doubleOnSubscribe() {
          TestHelper.checkDoubleOnSubscribeFlowable(new Function<Flowable<Object>, Flowable<Object>>() {
              @Override
              public Flowable<Object> apply(Flowable<Object> f)
                      throws Exception {
                  return f.sample(1, TimeUnit.SECONDS);
              }
          });
  
          TestHelper.checkDoubleOnSubscribeFlowable(new Function<Flowable<Object>, Flowable<Object>>() {
              @Override
              public Flowable<Object> apply(Flowable<Object> f)
                      throws Exception {
                  return f.sample(PublishProcessor.create());
              }
          });
      }
  
      @Test
      public void badRequest() {
          TestHelper.assertBadRequestReported(PublishProcessor.create()
                  .sample(PublishProcessor.create()));
      }
  
      @Test
      public void badRequestTimed() {
          TestHelper.assertBadRequestReported(PublishProcessor.create()
                  .sample(1, TimeUnit.MINUTES));
      }
  }
  