1/*
2 * Copyright (C) 2008 The Guava Authors
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package com.google.common.collect.testing.testers;
18
19import static com.google.common.collect.testing.features.CollectionSize.ZERO;
20import static com.google.common.collect.testing.features.MapFeature.SUPPORTS_CLEAR;
21
22import com.google.common.collect.testing.AbstractMapTester;
23import com.google.common.collect.testing.features.CollectionSize;
24import com.google.common.collect.testing.features.MapFeature;
25
26/**
27 * A generic JUnit test which tests {@code clear()} operations on a map.
28 * Can't be invoked directly; please see
29 * {@link com.google.common.collect.testing.MapTestSuiteBuilder}.
30 *
31 * <p>This class is GWT compatible.
32 *
33 * @author George van den Driessche
34 * @author Chris Povirk
35 */
36public class MapClearTester<K, V> extends AbstractMapTester<K, V> {
37  @MapFeature.Require(SUPPORTS_CLEAR)
38  public void testClear() {
39    getMap().clear();
40    assertTrue("After clear(), a map should be empty.",
41        getMap().isEmpty());
42  }
43
44  @MapFeature.Require(absent = SUPPORTS_CLEAR)
45  @CollectionSize.Require(absent = ZERO)
46  public void testClear_unsupported() {
47    try {
48      getMap().clear();
49      fail("clear() should throw UnsupportedOperation if a map does "
50          + "not support it and is not empty.");
51    } catch (UnsupportedOperationException expected) {
52    }
53    expectUnchanged();
54  }
55
56  @MapFeature.Require(absent = SUPPORTS_CLEAR)
57  @CollectionSize.Require(ZERO)
58  public void testClear_unsupportedByEmptyCollection() {
59    try {
60      getMap().clear();
61    } catch (UnsupportedOperationException tolerated) {
62    }
63    expectUnchanged();
64  }
65}
66