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.*;
  import static org.mockito.ArgumentMatchers.*;
  import static org.mockito.Mockito.*;
  
  import java.util.*;
  
  import org.junit.*;
  import org.mockito.InOrder;
  import org.reactivestreams.*;
  
  import io.reactivex.rxjava3.core.*;
  import io.reactivex.rxjava3.exceptions.TestException;
  import io.reactivex.rxjava3.functions.*;
  import io.reactivex.rxjava3.internal.functions.Functions;
  import io.reactivex.rxjava3.internal.subscriptions.BooleanSubscription;
  import io.reactivex.rxjava3.internal.util.ExceptionHelper;
  import io.reactivex.rxjava3.operators.QueueFuseable;
  import io.reactivex.rxjava3.operators.QueueSubscription;
  import io.reactivex.rxjava3.plugins.RxJavaPlugins;
  import io.reactivex.rxjava3.processors.UnicastProcessor;
  import io.reactivex.rxjava3.testsupport.*;
  
  public class FlowableDistinctTest extends RxJavaTest {
  
      Subscriber<String> w;
  
      // nulls lead to exceptions
      final Function<String, String> TO_UPPER_WITH_EXCEPTION = new Function<String, String>() {
          @Override
          public String apply(String s) {
              if (s.equals("x")) {
                  return "XX";
              }
              return s.toUpperCase();
          }
      };
  
      @Before
      public void before() {
          w = TestHelper.mockSubscriber();
      }
  
      @Test
      public void distinctOfNone() {
          Flowable<String> src = Flowable.empty();
          src.distinct().subscribe(w);
  
          verify(w, never()).onNext(anyString());
          verify(w, never()).onError(any(Throwable.class));
          verify(w, times(1)).onComplete();
      }
  
      @Test
      public void distinctOfNoneWithKeySelector() {
          Flowable<String> src = Flowable.empty();
          src.distinct(TO_UPPER_WITH_EXCEPTION).subscribe(w);
  
          verify(w, never()).onNext(anyString());
          verify(w, never()).onError(any(Throwable.class));
          verify(w, times(1)).onComplete();
      }
  
      @Test
      public void distinctOfNormalSource() {
          Flowable<String> src = Flowable.just("a", "b", "c", "c", "c", "b", "b", "a", "e");
          src.distinct().subscribe(w);
  
          InOrder inOrder = inOrder(w);
          inOrder.verify(w, times(1)).onNext("a");
          inOrder.verify(w, times(1)).onNext("b");
          inOrder.verify(w, times(1)).onNext("c");
          inOrder.verify(w, times(1)).onNext("e");
          inOrder.verify(w, times(1)).onComplete();
          inOrder.verify(w, never()).onNext(anyString());
          verify(w, never()).onError(any(Throwable.class));
      }
  
      @Test
      public void distinctOfNormalSourceWithKeySelector() {
          Flowable<String> src = Flowable.just("a", "B", "c", "C", "c", "B", "b", "a", "E");
          src.distinct(TO_UPPER_WITH_EXCEPTION).subscribe(w);
  
          InOrder inOrder = inOrder(w);
          inOrder.verify(w, times(1)).onNext("a");
          inOrder.verify(w, times(1)).onNext("B");
          inOrder.verify(w, times(1)).onNext("c");
          inOrder.verify(w, times(1)).onNext("E");
          inOrder.verify(w, times(1)).onComplete();
          inOrder.verify(w, never()).onNext(anyString());
          verify(w, never()).onError(any(Throwable.class));
      }
  
      @Test
      public void error() {
          Flowable.error(new TestException())
          .distinct()
          .test()
          .assertFailure(TestException.class);
      }
  
      @Test
      public void fusedSync() {
          TestSubscriberEx<Integer> ts = new TestSubscriberEx<Integer>().setInitialFusionMode(QueueFuseable.ANY);
  
          Flowable.just(1, 1, 2, 1, 3, 2, 4, 5, 4)
          .distinct()
          .subscribe(ts);
  
          ts.assertFusionMode(QueueFuseable.SYNC)
          .assertResult(1, 2, 3, 4, 5);
      }
  
      @Test
      public void fusedAsync() {
          TestSubscriberEx<Integer> ts = new TestSubscriberEx<Integer>().setInitialFusionMode(QueueFuseable.ANY);
  
          UnicastProcessor<Integer> up = UnicastProcessor.create();
  
          up
          .distinct()
          .subscribe(ts);
  
          TestHelper.emit(up, 1, 1, 2, 1, 3, 2, 4, 5, 4);
  
          ts.assertFusionMode(QueueFuseable.ASYNC)
          .assertResult(1, 2, 3, 4, 5);
      }
  
      @Test
      public void fusedClear() {
          Flowable.just(1, 1, 2, 1, 3, 2, 4, 5, 4)
          .distinct()
          .subscribe(new FlowableSubscriber<Integer>() {
              @Override
              public void onSubscribe(Subscription s) {
                  QueueSubscription<?> qs = (QueueSubscription<?>)s;
  
                  assertFalse(qs.isEmpty());
  
                  qs.clear();
  
                  assertTrue(qs.isEmpty());
              }
  
              @Override
              public void onNext(Integer value) {
              }
  
              @Override
              public void onError(Throwable e) {
              }
  
              @Override
              public void onComplete() {
              }
          });
      }
  
      @Test
      public void collectionSupplierThrows() {
          Flowable.just(1)
          .distinct(Functions.identity(), new Supplier<Collection<Object>>() {
              @Override
              public Collection<Object> get() throws Exception {
                  throw new TestException();
              }
          })
          .test()
          .assertFailure(TestException.class);
      }
  
      @Test
      public void collectionSupplierIsNull() {
          Flowable.just(1)
          .distinct(Functions.identity(), new Supplier<Collection<Object>>() {
              @Override
              public Collection<Object> get() throws Exception {
                  return null;
              }
          })
          .to(TestHelper.<Integer>testConsumer())
          .assertFailure(NullPointerException.class)
          .assertErrorMessage(ExceptionHelper.nullWarning("The collectionSupplier returned a null Collection."));
      }
  
      @Test
      public void badSource() {
          List<Throwable> errors = TestHelper.trackPluginErrors();
          try {
              new Flowable<Integer>() {
                  @Override
                  protected void subscribeActual(Subscriber<? super Integer> subscriber) {
                      subscriber.onSubscribe(new BooleanSubscription());
  
                      subscriber.onNext(1);
                      subscriber.onComplete();
                      subscriber.onNext(2);
                      subscriber.onError(new TestException());
                      subscriber.onComplete();
                  }
              }
              .distinct()
              .test()
              .assertResult(1);
  
              TestHelper.assertUndeliverable(errors, 0, TestException.class);
          } finally {
              RxJavaPlugins.reset();
          }
      }
  }
  