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 
17 package com.google.common.collect.testing.testers;
18 
19 import static com.google.common.collect.testing.features.CollectionFeature.ALLOWS_NULL_VALUES;
20 import static com.google.common.collect.testing.features.CollectionSize.ZERO;
21 import static com.google.common.collect.testing.features.ListFeature.SUPPORTS_SET;
22 
23 import com.google.common.annotations.GwtCompatible;
24 import com.google.common.annotations.GwtIncompatible;
25 import com.google.common.collect.testing.Helpers;
26 import com.google.common.collect.testing.features.CollectionFeature;
27 import com.google.common.collect.testing.features.CollectionSize;
28 import com.google.common.collect.testing.features.ListFeature;
29 
30 import java.lang.reflect.Method;
31 
32 /**
33  * A generic JUnit test which tests {@code set()} operations on a list. Can't be
34  * invoked directly; please see
35  * {@link com.google.common.collect.testing.ListTestSuiteBuilder}.
36  *
37  * @author George van den Driessche
38  */
39 @GwtCompatible(emulated = true)
40 public class ListSetTester<E> extends AbstractListTester<E> {
41   @ListFeature.Require(SUPPORTS_SET)
42   @CollectionSize.Require(absent = ZERO)
testSet()43   public void testSet() {
44     doTestSet(samples.e3);
45   }
46 
47   @CollectionSize.Require(absent = ZERO)
48   @CollectionFeature.Require(ALLOWS_NULL_VALUES)
49   @ListFeature.Require(SUPPORTS_SET)
testSet_null()50   public void testSet_null() {
51     doTestSet(null);
52   }
53 
54   @CollectionSize.Require(absent = ZERO)
55   @CollectionFeature.Require(ALLOWS_NULL_VALUES)
56   @ListFeature.Require(SUPPORTS_SET)
testSet_replacingNull()57   public void testSet_replacingNull() {
58     E[] elements = createSamplesArray();
59     int i = aValidIndex();
60     elements[i] = null;
61     collection = getSubjectGenerator().create(elements);
62 
63     doTestSet(samples.e3);
64   }
65 
doTestSet(E newValue)66   private void doTestSet(E newValue) {
67     int index = aValidIndex();
68     E initialValue = getList().get(index);
69     assertEquals("set(i, x) should return the old element at position i.",
70         initialValue, getList().set(index, newValue));
71     assertEquals("After set(i, x), get(i) should return x",
72         newValue, getList().get(index));
73     assertEquals("set() should not change the size of a list.",
74         getNumElements(), getList().size());
75   }
76 
77   @ListFeature.Require(SUPPORTS_SET)
testSet_indexTooLow()78   public void testSet_indexTooLow() {
79     try {
80       getList().set(-1, samples.e3);
81       fail("set(-1) should throw IndexOutOfBoundsException");
82     } catch (IndexOutOfBoundsException expected) {
83     }
84     expectUnchanged();
85   }
86 
87   @ListFeature.Require(SUPPORTS_SET)
testSet_indexTooHigh()88   public void testSet_indexTooHigh() {
89     int index = getNumElements();
90     try {
91       getList().set(index, samples.e3);
92       fail("set(size) should throw IndexOutOfBoundsException");
93     } catch (IndexOutOfBoundsException expected) {
94     }
95     expectUnchanged();
96   }
97 
98   @CollectionSize.Require(absent = ZERO)
99   @ListFeature.Require(absent = SUPPORTS_SET)
testSet_unsupported()100   public void testSet_unsupported() {
101     try {
102       getList().set(aValidIndex(), samples.e3);
103       fail("set() should throw UnsupportedOperationException");
104     } catch (UnsupportedOperationException expected) {
105     }
106     expectUnchanged();
107   }
108 
109   @CollectionSize.Require(ZERO)
110   @ListFeature.Require(absent = SUPPORTS_SET)
testSet_unsupportedByEmptyList()111   public void testSet_unsupportedByEmptyList() {
112     try {
113       getList().set(0, samples.e3);
114       fail("set() should throw UnsupportedOperationException "
115           + "or IndexOutOfBoundsException");
116     } catch (UnsupportedOperationException tolerated) {
117     } catch (IndexOutOfBoundsException tolerated) {
118     }
119     expectUnchanged();
120   }
121 
122   @CollectionSize.Require(absent = ZERO)
123   @ListFeature.Require(SUPPORTS_SET)
124   @CollectionFeature.Require(absent = ALLOWS_NULL_VALUES)
testSet_nullUnsupported()125   public void testSet_nullUnsupported() {
126     try {
127       getList().set(aValidIndex(), null);
128       fail("set(null) should throw NullPointerException");
129     } catch (NullPointerException expected) {
130     }
131     expectUnchanged();
132   }
133 
aValidIndex()134   private int aValidIndex() {
135     return getList().size() / 2;
136   }
137 
138   /**
139    * Returns the {@link java.lang.reflect.Method} instance for
140    * {@link #testSet_null()} so that tests of {@link
141    * java.util.Collections#checkedCollection(java.util.Collection, Class)} can
142    * suppress it with {@code FeatureSpecificTestSuiteBuilder.suppressing()}
143    * until <a
144    * href="http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6409434">Sun bug
145    * 6409434</a> is fixed. It's unclear whether nulls were to be permitted or
146    * forbidden, but presumably the eventual fix will be to permit them, as it
147    * seems more likely that code would depend on that behavior than on the
148    * other. Thus, we say the bug is in set(), which fails to support null.
149    */
150   @GwtIncompatible("reflection")
getSetNullSupportedMethod()151   public static Method getSetNullSupportedMethod() {
152     return Helpers.getMethod(ListSetTester.class, "testSet_null");
153   }
154 }
155