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.KNOWN_ORDER; 023import static com.google.common.collect.testing.features.CollectionFeature.SUPPORTS_ITERATOR_REMOVE; 024import static com.google.common.collect.testing.features.CollectionSize.ZERO; 025 026import com.google.common.annotations.GwtCompatible; 027import com.google.common.collect.testing.AbstractCollectionTester; 028import com.google.common.collect.testing.Helpers; 029import com.google.common.collect.testing.IteratorFeature; 030import com.google.common.collect.testing.IteratorTester; 031import com.google.common.collect.testing.features.CollectionFeature; 032import com.google.common.collect.testing.features.CollectionSize; 033import java.util.ArrayList; 034import java.util.Arrays; 035import java.util.Iterator; 036import java.util.List; 037import java.util.Map.Entry; 038import java.util.NoSuchElementException; 039import java.util.Set; 040 041/** 042 * A generic JUnit test which tests {@code iterator} operations on a collection. Can't be invoked 043 * directly; please see {@link com.google.common.collect.testing.CollectionTestSuiteBuilder}. 044 * 045 * @author Chris Povirk 046 */ 047@GwtCompatible(emulated = true) 048public class CollectionIteratorTester<E> extends AbstractCollectionTester<E> { 049 public void testIterator() { 050 List<E> iteratorElements = new ArrayList<E>(); 051 for (E element : collection) { // uses iterator() 052 iteratorElements.add(element); 053 } 054 Helpers.assertEqualIgnoringOrder(Arrays.asList(createSamplesArray()), iteratorElements); 055 } 056 057 @CollectionFeature.Require(KNOWN_ORDER) 058 public void testIterationOrdering() { 059 List<E> iteratorElements = new ArrayList<E>(); 060 for (E element : collection) { // uses iterator() 061 iteratorElements.add(element); 062 } 063 List<E> expected = Helpers.copyToList(getOrderedElements()); 064 assertEquals("Different ordered iteration", expected, iteratorElements); 065 } 066 067 @CollectionFeature.Require(SUPPORTS_ITERATOR_REMOVE) 068 @CollectionSize.Require(absent = ZERO) 069 public void testIterator_removeAffectsBackingCollection() { 070 int originalSize = collection.size(); 071 Iterator<E> iterator = collection.iterator(); 072 Object element = iterator.next(); 073 // If it's an Entry, it may become invalid once it's removed from the Map. Copy it. 074 if (element instanceof Entry) { 075 Entry<?, ?> entry = (Entry<?, ?>) element; 076 element = mapEntry(entry.getKey(), entry.getValue()); 077 } 078 assertTrue(collection.contains(element)); // sanity check 079 iterator.remove(); 080 assertFalse(collection.contains(element)); 081 assertEquals(originalSize - 1, collection.size()); 082 } 083 084 @CollectionFeature.Require({KNOWN_ORDER, SUPPORTS_ITERATOR_REMOVE}) 085 public void testIterator_knownOrderRemoveSupported() { 086 runIteratorTest(MODIFIABLE, IteratorTester.KnownOrder.KNOWN_ORDER, getOrderedElements()); 087 } 088 089 @CollectionFeature.Require(value = KNOWN_ORDER, absent = SUPPORTS_ITERATOR_REMOVE) 090 public void testIterator_knownOrderRemoveUnsupported() { 091 runIteratorTest(UNMODIFIABLE, IteratorTester.KnownOrder.KNOWN_ORDER, getOrderedElements()); 092 } 093 094 @CollectionFeature.Require(absent = KNOWN_ORDER, value = SUPPORTS_ITERATOR_REMOVE) 095 public void testIterator_unknownOrderRemoveSupported() { 096 runIteratorTest(MODIFIABLE, IteratorTester.KnownOrder.UNKNOWN_ORDER, getSampleElements()); 097 } 098 099 @CollectionFeature.Require(absent = {KNOWN_ORDER, SUPPORTS_ITERATOR_REMOVE}) 100 public void testIterator_unknownOrderRemoveUnsupported() { 101 runIteratorTest(UNMODIFIABLE, IteratorTester.KnownOrder.UNKNOWN_ORDER, getSampleElements()); 102 } 103 104 private void runIteratorTest( 105 Set<IteratorFeature> features, IteratorTester.KnownOrder knownOrder, Iterable<E> elements) { 106 new IteratorTester<E>( 107 Platform.collectionIteratorTesterNumIterations(), features, elements, knownOrder) { 108 @Override 109 protected Iterator<E> newTargetIterator() { 110 resetCollection(); 111 return collection.iterator(); 112 } 113 114 @Override 115 protected void verify(List<E> elements) { 116 expectContents(elements); 117 } 118 }.test(); 119 } 120 121 public void testIteratorNoSuchElementException() { 122 Iterator<E> iterator = collection.iterator(); 123 while (iterator.hasNext()) { 124 iterator.next(); 125 } 126 127 try { 128 iterator.next(); 129 fail("iterator.next() should throw NoSuchElementException"); 130 } catch (NoSuchElementException expected) { 131 } 132 } 133}