/*
    * Copyright (C) 2008 The Guava Authors
    *
    * 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 com.google.common.collect.testing.testers;
  
  import static com.google.common.collect.testing.features.CollectionFeature.ALLOWS_NULL_VALUES;
  import static com.google.common.collect.testing.features.CollectionFeature.SUPPORTS_ADD;
  
  import com.google.common.annotations.GwtCompatible;
  import com.google.common.collect.testing.features.CollectionFeature;
  
  /**
   * A generic JUnit test which tests offer operations on a queue. Can't be
   * invoked directly; please see
   * {@link com.google.common.collect.testing.CollectionTestSuiteBuilder}.
   *
   * @author Jared Levy
   */
  @SuppressWarnings("unchecked") // too many "unchecked generic array creations"
  @GwtCompatible
  public class QueueOfferTester<E> extends AbstractQueueTester<E> {
    @CollectionFeature.Require(SUPPORTS_ADD)
    public void testOffer_supportedNotPresent() {
      assertTrue("offer(notPresent) should return true",
          getQueue().offer(samples.e3));
      expectAdded(samples.e3);
    }
  
    @CollectionFeature.Require({SUPPORTS_ADD, ALLOWS_NULL_VALUES})
    public void testOffer_nullSupported() {
      assertTrue("offer(null) should return true", getQueue().offer(null));
      expectAdded((E) null);
    }
  
    @CollectionFeature.Require(value = SUPPORTS_ADD, absent = ALLOWS_NULL_VALUES)
    public void testOffer_nullUnsupported() {
      try {
        getQueue().offer(null);
        fail("offer(null) should throw");
      } catch (NullPointerException expected) {
      }
      expectUnchanged();
      expectNullMissingWhenNullUnsupported(
          "Should not contain null after unsupported offer(null)");
    }
  }