/*
    * Copyright (C) 2013 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.google;
  
  import static com.google.common.collect.testing.features.CollectionFeature.ALLOWS_NULL_VALUES;
  import static com.google.common.collect.testing.features.CollectionSize.ZERO;
  
  import com.google.common.annotations.GwtCompatible;
  import com.google.common.collect.testing.features.CollectionFeature;
  import com.google.common.collect.testing.features.CollectionSize;
  import com.google.common.testing.EqualsTester;
  
  /**
   * Tests for {@code Multiset.equals} and {@code Multiset.hashCode}.
   * 
   * @author Louis Wasserman
   */
  @GwtCompatible
  public class MultisetEqualsTester<E> extends AbstractMultisetTester<E> {
    public void testEqualsSameContents() {
      new EqualsTester()
          .addEqualityGroup(
              getMultiset(), 
              getSubjectGenerator().create(getSampleElements().toArray()))
          .testEquals();
    }
    
    @CollectionSize.Require(absent = ZERO)
    public void testNotEqualsEmpty() {
      new EqualsTester()
          .addEqualityGroup(getMultiset())
          .addEqualityGroup(getSubjectGenerator().create())
          .testEquals();
    }
    
    public void testHashCodeMatchesEntrySet() {
      assertEquals(getMultiset().entrySet().hashCode(), getMultiset().hashCode());
    }
    
    @CollectionSize.Require(absent = ZERO)
    @CollectionFeature.Require(ALLOWS_NULL_VALUES)
    public void testEqualsMultisetWithNullValue() {
      new EqualsTester()
          .addEqualityGroup(getMultiset())
          .addEqualityGroup(
              getSubjectGenerator().create(createArrayWithNullElement()),
              getSubjectGenerator().create(createArrayWithNullElement()))
          .testEquals();
    }
  }