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 java.util.concurrent.atomic.*;
  
  import org.junit.Test;
  import org.reactivestreams.Subscription;
  
  import io.reactivex.rxjava3.core.*;
  import io.reactivex.rxjava3.exceptions.TestException;
  import io.reactivex.rxjava3.functions.*;
  import io.reactivex.rxjava3.observers.DisposableCompletableObserver;
  import io.reactivex.rxjava3.operators.QueueFuseable;
  import io.reactivex.rxjava3.operators.QueueSubscription;
  import io.reactivex.rxjava3.processors.PublishProcessor;
  import io.reactivex.rxjava3.subscribers.*;
  import io.reactivex.rxjava3.testsupport.*;
  
  public class FlowableIgnoreElementsTest extends RxJavaTest {
  
      @Test
      public void withEmptyFlowable() {
          assertTrue(Flowable.empty().ignoreElements().toFlowable().isEmpty().blockingGet());
      }
  
      @Test
      public void withNonEmptyFlowable() {
          assertTrue(Flowable.just(1, 2, 3).ignoreElements().toFlowable().isEmpty().blockingGet());
      }
  
      @Test
      public void upstreamIsProcessedButIgnoredFlowable() {
          final int num = 10;
          final AtomicInteger upstreamCount = new AtomicInteger();
          long count = Flowable.range(1, num)
                  .doOnNext(new Consumer<Integer>() {
                      @Override
                      public void accept(Integer t) {
                          upstreamCount.incrementAndGet();
                      }
                  })
                  .ignoreElements()
                  .toFlowable()
                  .count().blockingGet();
          assertEquals(num, upstreamCount.get());
          assertEquals(0, count);
      }
  
      @Test
      public void completedOkFlowable() {
          TestSubscriberEx<Object> ts = new TestSubscriberEx<>();
          Flowable.range(1, 10).ignoreElements().toFlowable().subscribe(ts);
          ts.assertNoErrors();
          ts.assertNoValues();
          ts.assertTerminated();
      }
  
      @Test
      public void errorReceivedFlowable() {
          TestSubscriberEx<Object> ts = new TestSubscriberEx<>();
          TestException ex = new TestException("boo");
          Flowable.error(ex).ignoreElements().toFlowable().subscribe(ts);
          ts.assertNoValues();
          ts.assertTerminated();
          ts.assertError(TestException.class);
          ts.assertErrorMessage("boo");
      }
  
      @Test
      public void unsubscribesFromUpstreamFlowable() {
          final AtomicBoolean unsub = new AtomicBoolean();
          Flowable.range(1, 10).concatWith(Flowable.<Integer>never())
          .doOnCancel(new Action() {
              @Override
              public void run() {
                  unsub.set(true);
              }})
              .ignoreElements()
              .toFlowable()
              .subscribe().dispose();
  
          assertTrue(unsub.get());
      }
  
      @Test
      public void doesNotHangAndProcessesAllUsingBackpressureFlowable() {
          final AtomicInteger upstreamCount = new AtomicInteger();
          final AtomicInteger count = new AtomicInteger(0);
          int num = 10;
          Flowable.range(1, num)
          //
                  .doOnNext(new Consumer<Integer>() {
                      @Override
                      public void accept(Integer t) {
                          upstreamCount.incrementAndGet();
                      }
                  })
                  //
                  .ignoreElements()
                  .<Integer>toFlowable()
                  //
                  .doOnNext(new Consumer<Integer>() {
  
                      @Override
                      public void accept(Integer t) {
                          upstreamCount.incrementAndGet();
                      }
                  })
                  //
                  .subscribe(new DefaultSubscriber<Integer>() {
  
                      @Override
                      public void onStart() {
                          request(1);
                      }
  
                      @Override
                      public void onComplete() {
  
                      }
  
                      @Override
                      public void onError(Throwable e) {
                      }
  
                      @Override
                      public void onNext(Integer t) {
                          count.incrementAndGet();
                      }
                  });
          assertEquals(num, upstreamCount.get());
          assertEquals(0, count.get());
      }
  
      @Test
      public void withEmpty() {
          Flowable.empty().ignoreElements().blockingAwait();
      }
  
      @Test
      public void withNonEmpty() {
          Flowable.just(1, 2, 3).ignoreElements().blockingAwait();
      }
  
      @Test
      public void upstreamIsProcessedButIgnored() {
          final int num = 10;
          final AtomicInteger upstreamCount = new AtomicInteger();
          Flowable.range(1, num)
                  .doOnNext(new Consumer<Integer>() {
                      @Override
                      public void accept(Integer t) {
                          upstreamCount.incrementAndGet();
                      }
                  })
                  .ignoreElements()
                  .blockingAwait();
          assertEquals(num, upstreamCount.get());
      }
  
      @Test
      public void completedOk() {
          TestObserverEx<Object> to = new TestObserverEx<>();
          Flowable.range(1, 10).ignoreElements().subscribe(to);
          to.assertNoErrors();
          to.assertNoValues();
          to.assertTerminated();
      }
  
      @Test
      public void errorReceived() {
          TestObserverEx<Object> to = new TestObserverEx<>();
          TestException ex = new TestException("boo");
          Flowable.error(ex).ignoreElements().subscribe(to);
          to.assertNoValues();
          to.assertTerminated();
          to.assertError(TestException.class);
          to.assertErrorMessage("boo");
      }
  
      @Test
      public void unsubscribesFromUpstream() {
          final AtomicBoolean unsub = new AtomicBoolean();
          Flowable.range(1, 10).concatWith(Flowable.<Integer>never())
          .doOnCancel(new Action() {
              @Override
              public void run() {
                  unsub.set(true);
              }})
              .ignoreElements()
              .subscribe().dispose();
  
          assertTrue(unsub.get());
      }
  
      @Test
      public void doesNotHangAndProcessesAllUsingBackpressure() {
          final AtomicInteger upstreamCount = new AtomicInteger();
          final AtomicInteger count = new AtomicInteger(0);
          int num = 10;
          Flowable.range(1, num)
          //
                  .doOnNext(new Consumer<Integer>() {
                      @Override
                      public void accept(Integer t) {
                          upstreamCount.incrementAndGet();
                      }
                  })
                  //
                  .ignoreElements()
                  //
                  .subscribe(new DisposableCompletableObserver() {
                      @Override
                      public void onComplete() {
                      }
  
                      @Override
                      public void onError(Throwable e) {
                      }
                  });
          assertEquals(num, upstreamCount.get());
          assertEquals(0, count.get());
      }
  
      @Test
      public void cancel() {
  
          PublishProcessor<Integer> pp = PublishProcessor.create();
  
          TestSubscriber<Integer> ts = pp.ignoreElements().<Integer>toFlowable().test();
  
          assertTrue(pp.hasSubscribers());
  
          ts.cancel();
  
          assertFalse(pp.hasSubscribers());
      }
  
      @Test
      public void fused() {
          TestSubscriberEx<Integer> ts = new TestSubscriberEx<Integer>().setInitialFusionMode(QueueFuseable.ANY);
  
          Flowable.just(1).hide().ignoreElements().<Integer>toFlowable()
          .subscribe(ts);
  
          ts.assertFuseable()
          .assertFusionMode(QueueFuseable.ASYNC)
          .assertResult();
      }
  
      @Test
      public void fusedAPICalls() {
          Flowable.just(1).hide().ignoreElements().<Integer>toFlowable()
          .subscribe(new FlowableSubscriber<Integer>() {
  
              @Override
              public void onSubscribe(Subscription s) {
                  @SuppressWarnings("unchecked")
                  QueueSubscription<Integer> qs = (QueueSubscription<Integer>)s;
  
                  try {
                      assertNull(qs.poll());
                  } catch (Throwable ex) {
                      throw new AssertionError(ex);
                  }
  
                  assertTrue(qs.isEmpty());
  
                  qs.clear();
  
                  assertTrue(qs.isEmpty());
  
                  try {
                      assertNull(qs.poll());
                  } catch (Throwable ex) {
                      throw new AssertionError(ex);
                  }
  
                  try {
                      qs.offer(1);
                      fail("Should have thrown!");
                  } catch (UnsupportedOperationException ex) {
                      // expected
                  }
  
                  try {
                      qs.offer(1, 2);
                      fail("Should have thrown!");
                  } catch (UnsupportedOperationException ex) {
                      // expected
                  }
              }
  
              @Override
              public void onNext(Integer t) {
              }
  
              @Override
              public void onError(Throwable t) {
              }
  
              @Override
              public void onComplete() {
              }
          });
      }
  
      @Test
      public void dispose() {
          TestHelper.checkDisposed(Flowable.just(1).ignoreElements());
  
          TestHelper.checkDisposed(Flowable.just(1).ignoreElements().toFlowable());
      }
  
      @Test
      public void doubleOnSubscribe() {
          TestHelper.checkDoubleOnSubscribeFlowable(new Function<Flowable<Object>, Flowable<Object>>() {
              @Override
              public Flowable<Object> apply(Flowable<Object> f)
                      throws Exception {
                  return f.ignoreElements().toFlowable();
              }
          });
  
          TestHelper.checkDoubleOnSubscribeFlowableToCompletable(new Function<Flowable<Object>, Completable>() {
              @Override
              public Completable apply(Flowable<Object> f)
                      throws Exception {
                  return f.ignoreElements();
              }
          });
      }
  }
  