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      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.IteratorFeature.MODIFIABLE;
     20 import static com.google.common.collect.testing.IteratorFeature.UNMODIFIABLE;
     21 import static com.google.common.collect.testing.features.CollectionFeature.KNOWN_ORDER;
     22 import static com.google.common.collect.testing.features.CollectionFeature.SUPPORTS_REMOVE;
     23 
     24 import com.google.common.collect.testing.AbstractCollectionTester;
     25 import com.google.common.collect.testing.Helpers;
     26 import com.google.common.collect.testing.IteratorFeature;
     27 import com.google.common.collect.testing.IteratorTester;
     28 import com.google.common.collect.testing.features.CollectionFeature;
     29 
     30 import java.lang.reflect.Method;
     31 import java.util.ArrayList;
     32 import java.util.Arrays;
     33 import java.util.Iterator;
     34 import java.util.List;
     35 import java.util.NoSuchElementException;
     36 import java.util.Set;
     37 import java.util.concurrent.CopyOnWriteArrayList;
     38 import java.util.concurrent.CopyOnWriteArraySet;
     39 
     40 /**
     41  * A generic JUnit test which tests {@code iterator} operations on a collection.
     42  * Can't be invoked directly; please see
     43  * {@link com.google.common.collect.testing.CollectionTestSuiteBuilder}.
     44  *
     45  * <p>This class is GWT compatible.
     46  *
     47  * @author Chris Povirk
     48  */
     49 public class CollectionIteratorTester<E> extends AbstractCollectionTester<E> {
     50   public void testIterator() {
     51     List<E> iteratorElements = new ArrayList<E>();
     52     for (E element : collection) { // uses iterator()
     53       iteratorElements.add(element);
     54     }
     55     Helpers.assertEqualIgnoringOrder(
     56         Arrays.asList(createSamplesArray()), iteratorElements);
     57   }
     58 
     59   @CollectionFeature.Require(KNOWN_ORDER)
     60   public void testIterationOrdering() {
     61     List<E> iteratorElements = new ArrayList<E>();
     62     for (E element : collection) { // uses iterator()
     63       iteratorElements.add(element);
     64     }
     65     List<E> expected = Helpers.copyToList(getOrderedElements());
     66     assertEquals("Different ordered iteration", expected, iteratorElements);
     67   }
     68 
     69   // TODO: switch to DerivedIteratorTestSuiteBuilder
     70 
     71   @CollectionFeature.Require({KNOWN_ORDER, SUPPORTS_REMOVE})
     72   public void testIterator_knownOrderRemoveSupported() {
     73     runIteratorTest(MODIFIABLE, IteratorTester.KnownOrder.KNOWN_ORDER,
     74         getOrderedElements());
     75   }
     76 
     77   @CollectionFeature.Require(value = KNOWN_ORDER, absent = SUPPORTS_REMOVE)
     78   public void testIterator_knownOrderRemoveUnsupported() {
     79     runIteratorTest(UNMODIFIABLE, IteratorTester.KnownOrder.KNOWN_ORDER,
     80         getOrderedElements());
     81   }
     82 
     83   @CollectionFeature.Require(absent = KNOWN_ORDER, value = SUPPORTS_REMOVE)
     84   public void testIterator_unknownOrderRemoveSupported() {
     85     runIteratorTest(MODIFIABLE, IteratorTester.KnownOrder.UNKNOWN_ORDER,
     86         getSampleElements());
     87   }
     88 
     89   @CollectionFeature.Require(absent = {KNOWN_ORDER, SUPPORTS_REMOVE})
     90   public void testIterator_unknownOrderRemoveUnsupported() {
     91     runIteratorTest(UNMODIFIABLE, IteratorTester.KnownOrder.UNKNOWN_ORDER,
     92         getSampleElements());
     93   }
     94 
     95   private void runIteratorTest(Set<IteratorFeature> features,
     96       IteratorTester.KnownOrder knownOrder, Iterable<E> elements) {
     97     new IteratorTester<E>(Platform.collectionIteratorTesterNumIterations(), features, elements,
     98         knownOrder) {
     99       {
    100         // TODO: don't set this universally
    101         ignoreSunJavaBug6529795();
    102       }
    103 
    104       @Override protected Iterator<E> newTargetIterator() {
    105         resetCollection();
    106         return collection.iterator();
    107       }
    108 
    109       @Override protected void verify(List<E> elements) {
    110         expectContents(elements);
    111       }
    112     }.test();
    113   }
    114 
    115   /**
    116    * Returns the {@link Method} instance for
    117    * {@link #testIterator_knownOrderRemoveSupported()} so that tests of
    118    * {@link CopyOnWriteArraySet} and {@link CopyOnWriteArrayList} can suppress
    119    * it with {@code FeatureSpecificTestSuiteBuilder.suppressing()} until <a
    120    * href="http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6570575">Sun bug
    121    * 6570575</a> is fixed.
    122    */
    123   public static Method getIteratorKnownOrderRemoveSupportedMethod() {
    124     return Platform.getMethod(
    125           CollectionIteratorTester.class, "testIterator_knownOrderRemoveSupported");
    126   }
    127 
    128   /**
    129    * Returns the {@link Method} instance for
    130    * {@link #testIterator_unknownOrderRemoveSupported()} so that tests of
    131    * classes with unmodifiable iterators can suppress it.
    132    */
    133   public static Method getIteratorUnknownOrderRemoveSupportedMethod() {
    134     return Platform.getMethod(
    135         CollectionIteratorTester.class, "testIterator_unknownOrderRemoveSupported");
    136   }
    137 
    138   public void testIteratorNoSuchElementException() {
    139     Iterator<E> iterator = collection.iterator();
    140     while (iterator.hasNext()) {
    141       iterator.next();
    142     }
    143 
    144     try {
    145       iterator.next();
    146       fail("iterator.next() should throw NoSuchElementException");
    147     } catch (NoSuchElementException expected) {}
    148   }
    149 
    150   /**
    151    * Returns the {@link Method} instance for
    152    * {@link #testIterator_knownOrderRemoveUnsupported()} so that tests of
    153    * {@code ArrayStack} can suppress it with
    154    * {@code FeatureSpecificTestSuiteBuilder.suppressing()}. {@code ArrayStack}
    155    * supports {@code remove()} on only the first element, and the iterator
    156    * tester can't handle that.
    157    */
    158   public static Method getIteratorKnownOrderRemoveUnsupportedMethod() {
    159     return Platform.getMethod(
    160         CollectionIteratorTester.class, "testIterator_knownOrderRemoveUnsupported");
    161   }
    162 }
    163