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.subscriptions;
  
  import static org.junit.Assert.assertEquals;
  
  import org.junit.Test;
  
  import io.reactivex.rxjava3.annotations.Nullable;
  import io.reactivex.rxjava3.core.RxJavaTest;
  import io.reactivex.rxjava3.testsupport.TestHelper;
  
  public class QueueSubscriptionTest extends RxJavaTest {
      static final class EmptyQS extends BasicQueueSubscription<Integer> {
  
          private static final long serialVersionUID = -5312809687598840520L;
  
          @Override
          public int requestFusion(int mode) {
              return 0;
          }
  
          @Nullable
          @Override
          public Integer poll() throws Exception {
              return null;
          }
  
          @Override
          public boolean isEmpty() {
              return false;
          }
  
          @Override
          public void clear() {
  
          }
  
          @Override
          public void request(long n) {
  
          }
  
          @Override
          public void cancel() {
  
          }
  
      }
  
      static final class EmptyIntQS extends BasicIntQueueSubscription<Integer> {
  
          private static final long serialVersionUID = -1374033403007296252L;
  
          @Override
          public int requestFusion(int mode) {
              return 0;
          }
  
          @Nullable
          @Override
          public Integer poll() throws Exception {
              return null;
          }
  
          @Override
          public boolean isEmpty() {
              return false;
          }
  
          @Override
          public void clear() {
  
          }
  
          @Override
          public void request(long n) {
  
          }
  
          @Override
          public void cancel() {
  
          }
  
      }
  
      @Test
      public void noOfferBasic() {
          TestHelper.assertNoOffer(new EmptyQS());
      }
  
      @Test
      public void noOfferBasicInt() {
          TestHelper.assertNoOffer(new EmptyIntQS());
      }
  
      @Test
      public void empty() {
          TestHelper.checkEnum(EmptySubscription.class);
  
          assertEquals("EmptySubscription", EmptySubscription.INSTANCE.toString());
  
          TestHelper.assertNoOffer(EmptySubscription.INSTANCE);
      }
  }
  