001/* 002 * Copyright (C) 2008 The Guava Authors 003 * 004 * Licensed under the Apache License, Version 2.0 (the "License"); 005 * you may not use this file except in compliance with the License. 006 * You may obtain a copy of the License at 007 * 008 * http://www.apache.org/licenses/LICENSE-2.0 009 * 010 * Unless required by applicable law or agreed to in writing, software 011 * distributed under the License is distributed on an "AS IS" BASIS, 012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 013 * See the License for the specific language governing permissions and 014 * limitations under the License. 015 */ 016 017package com.google.common.collect.testing.testers; 018 019import static com.google.common.collect.testing.Helpers.mapEntry; 020import static com.google.common.collect.testing.IteratorFeature.MODIFIABLE; 021import static com.google.common.collect.testing.IteratorFeature.UNMODIFIABLE; 022import static com.google.common.collect.testing.features.CollectionFeature.ALLOWS_NULL_VALUES; 023import static com.google.common.collect.testing.features.CollectionFeature.KNOWN_ORDER; 024import static com.google.common.collect.testing.features.CollectionFeature.SUPPORTS_ITERATOR_REMOVE; 025import static com.google.common.collect.testing.features.CollectionSize.ZERO; 026import static java.util.Arrays.asList; 027 028import com.google.common.annotations.GwtCompatible; 029import com.google.common.collect.testing.AbstractCollectionTester; 030import com.google.common.collect.testing.Helpers; 031import com.google.common.collect.testing.IteratorFeature; 032import com.google.common.collect.testing.IteratorTester; 033import com.google.common.collect.testing.features.CollectionFeature; 034import com.google.common.collect.testing.features.CollectionSize; 035import java.util.ArrayList; 036import java.util.Arrays; 037import java.util.Iterator; 038import java.util.List; 039import java.util.Map.Entry; 040import java.util.NoSuchElementException; 041import java.util.Set; 042import org.junit.Ignore; 043 044/** 045 * A generic JUnit test which tests {@code iterator} operations on a collection. Can't be invoked 046 * directly; please see {@link com.google.common.collect.testing.CollectionTestSuiteBuilder}. 047 * 048 * @author Chris Povirk 049 */ 050@GwtCompatible(emulated = true) 051@Ignore // Affects only Android test runner, which respects JUnit 4 annotations on JUnit 3 tests. 052public class CollectionIteratorTester<E> extends AbstractCollectionTester<E> { 053 public void testIterator() { 054 List<E> iteratorElements = new ArrayList<E>(); 055 for (E element : collection) { // uses iterator() 056 iteratorElements.add(element); 057 } 058 Helpers.assertEqualIgnoringOrder(Arrays.asList(createSamplesArray()), iteratorElements); 059 } 060 061 @CollectionFeature.Require(KNOWN_ORDER) 062 public void testIterationOrdering() { 063 List<E> iteratorElements = new ArrayList<E>(); 064 for (E element : collection) { // uses iterator() 065 iteratorElements.add(element); 066 } 067 List<E> expected = Helpers.copyToList(getOrderedElements()); 068 assertEquals("Different ordered iteration", expected, iteratorElements); 069 } 070 071 @CollectionFeature.Require(ALLOWS_NULL_VALUES) 072 @CollectionSize.Require(absent = ZERO) 073 public void testIterator_nullElement() { 074 initCollectionWithNullElement(); 075 List<E> iteratorElements = new ArrayList<E>(); 076 for (E element : collection) { // uses iterator() 077 iteratorElements.add(element); 078 } 079 Helpers.assertEqualIgnoringOrder(asList(createArrayWithNullElement()), iteratorElements); 080 } 081 082 @CollectionFeature.Require(SUPPORTS_ITERATOR_REMOVE) 083 @CollectionSize.Require(absent = ZERO) 084 public void testIterator_removeAffectsBackingCollection() { 085 int originalSize = collection.size(); 086 Iterator<E> iterator = collection.iterator(); 087 Object element = iterator.next(); 088 // If it's an Entry, it may become invalid once it's removed from the Map. Copy it. 089 if (element instanceof Entry) { 090 Entry<?, ?> entry = (Entry<?, ?>) element; 091 element = mapEntry(entry.getKey(), entry.getValue()); 092 } 093 assertTrue(collection.contains(element)); // sanity check 094 iterator.remove(); 095 assertFalse(collection.contains(element)); 096 assertEquals(originalSize - 1, collection.size()); 097 } 098 099 @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}