/*
    * 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.CollectionSize.SEVERAL;
  import static com.google.common.collect.testing.features.CollectionSize.ZERO;
  import static com.google.common.collect.testing.features.MapFeature.ALLOWS_NULL_KEYS;
  import static com.google.common.collect.testing.features.MapFeature.ALLOWS_NULL_KEY_QUERIES;
  import static com.google.common.collect.testing.features.MapFeature.FAILS_FAST_ON_CONCURRENT_MODIFICATION;
  import static com.google.common.collect.testing.features.MapFeature.SUPPORTS_REMOVE;
  
  import com.google.common.annotations.GwtCompatible;
  import com.google.common.collect.testing.AbstractMapTester;
  import com.google.common.collect.testing.WrongType;
  import com.google.common.collect.testing.features.CollectionSize;
  import com.google.common.collect.testing.features.MapFeature;
  
  import java.util.ConcurrentModificationException;
  import java.util.Iterator;
  import java.util.Map.Entry;
  
  /**
   * A generic JUnit test which tests {@code remove} operations on a map. Can't be
   * invoked directly; please see
   * {@link com.google.common.collect.testing.MapTestSuiteBuilder}.
   *
   * @author George van den Driessche
   * @author Chris Povirk
   */
  @SuppressWarnings("unchecked") // too many "unchecked generic array creations"
  @GwtCompatible
  public class MapRemoveTester<K, V> extends AbstractMapTester<K, V> {
    @MapFeature.Require(SUPPORTS_REMOVE)
    @CollectionSize.Require(absent = ZERO)
    public void testRemove_present() {
      int initialSize = getMap().size();
      assertEquals("remove(present) should return the associated value",
          samples.e0.getValue(), getMap().remove(samples.e0.getKey()));
      assertEquals("remove(present) should decrease a map's size by one.",
          initialSize - 1, getMap().size());
      expectMissing(samples.e0);
    }
  
    @MapFeature.Require({FAILS_FAST_ON_CONCURRENT_MODIFICATION,
        SUPPORTS_REMOVE})
    @CollectionSize.Require(SEVERAL)
    public void testRemovePresentConcurrentWithEntrySetIteration() {
      try {
        Iterator<Entry<K, V>> iterator = getMap().entrySet().iterator();
        getMap().remove(samples.e0.getKey());
        iterator.next();
        fail("Expected ConcurrentModificationException");
      } catch (ConcurrentModificationException expected) {
        // success
      }
    }
  
    @MapFeature.Require({FAILS_FAST_ON_CONCURRENT_MODIFICATION,
        SUPPORTS_REMOVE})
    @CollectionSize.Require(SEVERAL)
    public void testRemovePresentConcurrentWithKeySetIteration() {
      try {
        Iterator<K> iterator = getMap().keySet().iterator();
        getMap().remove(samples.e0.getKey());
        iterator.next();
        fail("Expected ConcurrentModificationException");
      } catch (ConcurrentModificationException expected) {
        // success
      }
    }
  
    @MapFeature.Require({FAILS_FAST_ON_CONCURRENT_MODIFICATION,
        SUPPORTS_REMOVE})
    @CollectionSize.Require(SEVERAL)
    public void testRemovePresentConcurrentWithValuesIteration() {
      try {
        Iterator<V> iterator = getMap().values().iterator();
        getMap().remove(samples.e0.getKey());
        iterator.next();
        fail("Expected ConcurrentModificationException");
      } catch (ConcurrentModificationException expected) {
        // success
      }
    }
  
   @MapFeature.Require(SUPPORTS_REMOVE)
   public void testRemove_notPresent() {
     assertNull("remove(notPresent) should return null",
         getMap().remove(samples.e3.getKey()));
     expectUnchanged();
   }
 
   @MapFeature.Require({SUPPORTS_REMOVE, ALLOWS_NULL_KEYS})
   @CollectionSize.Require(absent = ZERO)
   public void testRemove_nullPresent() {
     initMapWithNullKey();
 
     int initialSize = getMap().size();
     assertEquals("remove(null) should return the associated value",
         getValueForNullKey(), getMap().remove(null));
     assertEquals("remove(present) should decrease a map's size by one.",
         initialSize - 1, getMap().size());
     expectMissing(entry(null, getValueForNullKey()));
   }
 
   @MapFeature.Require(absent = SUPPORTS_REMOVE)
   @CollectionSize.Require(absent = ZERO)
   public void testRemove_unsupported() {
     try {
       getMap().remove(samples.e0.getKey());
       fail("remove(present) should throw UnsupportedOperationException");
     } catch (UnsupportedOperationException expected) {
     }
     expectUnchanged();
     assertEquals("remove(present) should not remove the element",
         samples.e0.getValue(), get(samples.e0.getKey()));
   }
 
   @MapFeature.Require(absent = SUPPORTS_REMOVE)
   public void testRemove_unsupportedNotPresent() {
     try {
       assertNull("remove(notPresent) should return null or throw "
           + "UnsupportedOperationException",
           getMap().remove(samples.e3.getKey()));
     } catch (UnsupportedOperationException tolerated) {
     }
     expectUnchanged();
     expectMissing(samples.e3);
   }
 
   @MapFeature.Require(
       value = SUPPORTS_REMOVE,
       absent = ALLOWS_NULL_KEY_QUERIES)
   public void testRemove_nullQueriesNotSupported() {
     try {
       assertNull("remove(null) should return null or throw "
           + "NullPointerException",
           getMap().remove(null));
     } catch (NullPointerException tolerated) {
     }
     expectUnchanged();
   }
 
   @MapFeature.Require({SUPPORTS_REMOVE, ALLOWS_NULL_KEY_QUERIES})
   public void testRemove_nullSupportedMissing() {
     assertNull("remove(null) should return null", getMap().remove(null));
     expectUnchanged();
   }
 
   @MapFeature.Require(SUPPORTS_REMOVE)
   public void testRemove_wrongType() {
     try {
       assertNull(getMap().remove(WrongType.VALUE));
     } catch (ClassCastException tolerated) {
     }
     expectUnchanged();
   }
 }