Coverage Summary for Class: CollectionIteratorTester (com.google.common.collect.testing.testers)

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.Helpers.mapEntry;
20 import static com.google.common.collect.testing.IteratorFeature.MODIFIABLE;
21 import static com.google.common.collect.testing.IteratorFeature.UNMODIFIABLE;
22 import static com.google.common.collect.testing.features.CollectionFeature.ALLOWS_NULL_VALUES;
23 import static com.google.common.collect.testing.features.CollectionFeature.KNOWN_ORDER;
24 import static com.google.common.collect.testing.features.CollectionFeature.SUPPORTS_ITERATOR_REMOVE;
25 import static com.google.common.collect.testing.features.CollectionSize.ZERO;
26 import static java.util.Arrays.asList;
27 
28 import com.google.common.annotations.GwtCompatible;
29 import com.google.common.collect.testing.AbstractCollectionTester;
30 import com.google.common.collect.testing.Helpers;
31 import com.google.common.collect.testing.IteratorFeature;
32 import com.google.common.collect.testing.IteratorTester;
33 import com.google.common.collect.testing.features.CollectionFeature;
34 import com.google.common.collect.testing.features.CollectionSize;
35 import java.util.ArrayList;
36 import java.util.Arrays;
37 import java.util.Iterator;
38 import java.util.List;
39 import java.util.Map.Entry;
40 import java.util.NoSuchElementException;
41 import java.util.Set;
42 import org.junit.Ignore;
43 
44 /**
45  * A generic JUnit test which tests {@code iterator} operations on a collection. Can't be invoked
46  * directly; please see {@link com.google.common.collect.testing.CollectionTestSuiteBuilder}.
47  *
48  * @author Chris Povirk
49  */
50 @GwtCompatible(emulated = true)
51 @Ignore // Affects only Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.
52 public class CollectionIteratorTester<E> extends AbstractCollectionTester<E> {
53   public void testIterator() {
54     List<E> iteratorElements = new ArrayList<E>();
55     for (E element : collection) { // uses iterator()
56       iteratorElements.add(element);
57     }
58     Helpers.assertEqualIgnoringOrder(Arrays.asList(createSamplesArray()), iteratorElements);
59   }
60 
61   @CollectionFeature.Require(KNOWN_ORDER)
62   public void testIterationOrdering() {
63     List<E> iteratorElements = new ArrayList<E>();
64     for (E element : collection) { // uses iterator()
65       iteratorElements.add(element);
66     }
67     List<E> expected = Helpers.copyToList(getOrderedElements());
68     assertEquals("Different ordered iteration", expected, iteratorElements);
69   }
70 
71   @CollectionFeature.Require(ALLOWS_NULL_VALUES)
72   @CollectionSize.Require(absent = ZERO)
73   public void testIterator_nullElement() {
74     initCollectionWithNullElement();
75     List<E> iteratorElements = new ArrayList<E>();
76     for (E element : collection) { // uses iterator()
77       iteratorElements.add(element);
78     }
79     Helpers.assertEqualIgnoringOrder(asList(createArrayWithNullElement()), iteratorElements);
80   }
81 
82   @CollectionFeature.Require(SUPPORTS_ITERATOR_REMOVE)
83   @CollectionSize.Require(absent = ZERO)
84   public void testIterator_removeAffectsBackingCollection() {
85     int originalSize = collection.size();
86     Iterator<E> iterator = collection.iterator();
87     Object element = iterator.next();
88     // If it's an Entry, it may become invalid once it's removed from the Map. Copy it.
89     if (element instanceof Entry) {
90       Entry<?, ?> entry = (Entry<?, ?>) element;
91       element = mapEntry(entry.getKey(), entry.getValue());
92     }
93     assertTrue(collection.contains(element)); // sanity check
94     iterator.remove();
95     assertFalse(collection.contains(element));
96     assertEquals(originalSize - 1, collection.size());
97   }
98 
99   @CollectionFeature.Require({KNOWN_ORDER, SUPPORTS_ITERATOR_REMOVE})
100   public void testIterator_knownOrderRemoveSupported() {
101     runIteratorTest(MODIFIABLE, IteratorTester.KnownOrder.KNOWN_ORDER, getOrderedElements());
102   }
103 
104   @CollectionFeature.Require(value = KNOWN_ORDER, absent = SUPPORTS_ITERATOR_REMOVE)
105   public void testIterator_knownOrderRemoveUnsupported() {
106     runIteratorTest(UNMODIFIABLE, IteratorTester.KnownOrder.KNOWN_ORDER, getOrderedElements());
107   }
108 
109   @CollectionFeature.Require(absent = KNOWN_ORDER, value = SUPPORTS_ITERATOR_REMOVE)
110   public void testIterator_unknownOrderRemoveSupported() {
111     runIteratorTest(MODIFIABLE, IteratorTester.KnownOrder.UNKNOWN_ORDER, getSampleElements());
112   }
113 
114   @CollectionFeature.Require(absent = {KNOWN_ORDER, SUPPORTS_ITERATOR_REMOVE})
115   public void testIterator_unknownOrderRemoveUnsupported() {
116     runIteratorTest(UNMODIFIABLE, IteratorTester.KnownOrder.UNKNOWN_ORDER, getSampleElements());
117   }
118 
119   private void runIteratorTest(
120       Set<IteratorFeature> features, IteratorTester.KnownOrder knownOrder, Iterable<E> elements) {
121     new IteratorTester<E>(
122         Platform.collectionIteratorTesterNumIterations(), features, elements, knownOrder) {
123       @Override
124       protected Iterator<E> newTargetIterator() {
125         resetCollection();
126         return collection.iterator();
127       }
128 
129       @Override
130       protected void verify(List<E> elements) {
131         expectContents(elements);
132       }
133     }.test();
134   }
135 
136   public void testIteratorNoSuchElementException() {
137     Iterator<E> iterator = collection.iterator();
138     while (iterator.hasNext()) {
139       iterator.next();
140     }
141 
142     try {
143       iterator.next();
144       fail("iterator.next() should throw NoSuchElementException");
145     } catch (NoSuchElementException expected) {
146     }
147   }
148 }