/*
    * Copyright (C) 2007 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;
  
  import com.google.common.annotations.GwtCompatible;
  
  import junit.framework.TestCase;
  
  import java.util.Collections;
  import java.util.Map.Entry;
  
  /**
   * Tests for {@code AbstractMapEntry}.
   *
   * @author Mike Bostock
   */
  @GwtCompatible
  public class AbstractMapEntryTest extends TestCase {
    private static final String NK = null;
    private static final Integer NV = null;
  
    private static <K, V> Entry<K, V> entry(final K key, final V value) {
      return new AbstractMapEntry<K, V>() {
          @Override public K getKey() {
            return key;
          }
          @Override public V getValue() {
            return value;
          }
        };
    }
  
    private static <K, V> Entry<K, V> control(K key, V value) {
      return Collections.singletonMap(key, value).entrySet().iterator().next();
    }
  
    public void testToString() {
      assertEquals("foo=1", entry("foo", 1).toString());
    }
  
    public void testToStringNull() {
      assertEquals("null=1", entry(NK, 1).toString());
      assertEquals("foo=null", entry("foo", NV).toString());
      assertEquals("null=null", entry(NK, NV).toString());
    }
  
    public void testEquals() {
      Entry<String, Integer> foo1 = entry("foo", 1);
      assertEquals(foo1, foo1);
      assertEquals(control("foo", 1), foo1);
      assertEquals(control("bar", 2), entry("bar", 2));
      assertFalse(control("foo", 1).equals(entry("foo", 2)));
      assertFalse(foo1.equals(control("bar", 1)));
      assertFalse(foo1.equals(new Object()));
      assertFalse(foo1.equals(null));
    }
  
    public void testEqualsNull() {
      assertEquals(control(NK, 1), entry(NK, 1));
      assertEquals(control("bar", NV), entry("bar", NV));
      assertFalse(control(NK, 1).equals(entry(NK, 2)));
      assertFalse(entry(NK, 1).equals(control("bar", 1)));
      assertFalse(entry(NK, 1).equals(new Object()));
      assertFalse(entry(NK, 1).equals(null));
    }
  
    public void testHashCode() {
      assertEquals(control("foo", 1).hashCode(), entry("foo", 1).hashCode());
      assertEquals(control("bar", 2).hashCode(), entry("bar", 2).hashCode());
    }
  
    public void testHashCodeNull() {
      assertEquals(control(NK, 1).hashCode(), entry(NK, 1).hashCode());
      assertEquals(control("bar", NV).hashCode(), entry("bar", NV).hashCode());
      assertEquals(control(NK, NV).hashCode(), entry(NK, NV).hashCode());
    }
  }