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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_ITERATOR_REMOVE;
     23 
     24 import com.google.common.annotations.GwtCompatible;
     25 import com.google.common.annotations.GwtIncompatible;
     26 import com.google.common.collect.testing.AbstractCollectionTester;
     27 import com.google.common.collect.testing.Helpers;
     28 import com.google.common.collect.testing.IteratorFeature;
     29 import com.google.common.collect.testing.IteratorTester;
     30 import com.google.common.collect.testing.features.CollectionFeature;
     31 
     32 import java.lang.reflect.Method;
     33 import java.util.ArrayList;
     34 import java.util.Arrays;
     35 import java.util.Iterator;
     36 import java.util.List;
     37 import java.util.NoSuchElementException;
     38 import java.util.Set;
     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  * @author Chris Povirk
     46  */
     47 @GwtCompatible(emulated = true)
     48 public class CollectionIteratorTester<E> extends AbstractCollectionTester<E> {
     49   public void testIterator() {
     50     List<E> iteratorElements = new ArrayList<E>();
     51     for (E element : collection) { // uses iterator()
     52       iteratorElements.add(element);
     53     }
     54     Helpers.assertEqualIgnoringOrder(
     55         Arrays.asList(createSamplesArray()), iteratorElements);
     56   }
     57 
     58   @CollectionFeature.Require(KNOWN_ORDER)
     59   public void testIterationOrdering() {
     60     List<E> iteratorElements = new ArrayList<E>();
     61     for (E element : collection) { // uses iterator()
     62       iteratorElements.add(element);
     63     }
     64     List<E> expected = Helpers.copyToList(getOrderedElements());
     65     assertEquals("Different ordered iteration", expected, iteratorElements);
     66   }
     67 
     68   // TODO: switch to DerivedIteratorTestSuiteBuilder
     69 
     70   @CollectionFeature.Require({KNOWN_ORDER, SUPPORTS_ITERATOR_REMOVE})
     71   public void testIterator_knownOrderRemoveSupported() {
     72     runIteratorTest(MODIFIABLE, IteratorTester.KnownOrder.KNOWN_ORDER,
     73         getOrderedElements());
     74   }
     75 
     76   @CollectionFeature.Require(value = KNOWN_ORDER, absent = SUPPORTS_ITERATOR_REMOVE)
     77   public void testIterator_knownOrderRemoveUnsupported() {
     78     runIteratorTest(UNMODIFIABLE, IteratorTester.KnownOrder.KNOWN_ORDER,
     79         getOrderedElements());
     80   }
     81 
     82   @CollectionFeature.Require(absent = KNOWN_ORDER, value = SUPPORTS_ITERATOR_REMOVE)
     83   public void testIterator_unknownOrderRemoveSupported() {
     84     runIteratorTest(MODIFIABLE, IteratorTester.KnownOrder.UNKNOWN_ORDER,
     85         getSampleElements());
     86   }
     87 
     88   @CollectionFeature.Require(absent = {KNOWN_ORDER, SUPPORTS_ITERATOR_REMOVE})
     89   public void testIterator_unknownOrderRemoveUnsupported() {
     90     runIteratorTest(UNMODIFIABLE, IteratorTester.KnownOrder.UNKNOWN_ORDER,
     91         getSampleElements());
     92   }
     93 
     94   private void runIteratorTest(Set<IteratorFeature> features,
     95       IteratorTester.KnownOrder knownOrder, Iterable<E> elements) {
     96     new IteratorTester<E>(Platform.collectionIteratorTesterNumIterations(), features, elements,
     97         knownOrder) {
     98       @Override protected Iterator<E> newTargetIterator() {
     99         resetCollection();
    100         return collection.iterator();
    101       }
    102 
    103       @Override protected void verify(List<E> elements) {
    104         expectContents(elements);
    105       }
    106     }.test();
    107   }
    108 
    109   public void testIteratorNoSuchElementException() {
    110     Iterator<E> iterator = collection.iterator();
    111     while (iterator.hasNext()) {
    112       iterator.next();
    113     }
    114 
    115     try {
    116       iterator.next();
    117       fail("iterator.next() should throw NoSuchElementException");
    118     } catch (NoSuchElementException expected) {}
    119   }
    120 
    121   /**
    122    * Returns the {@link Method} instance for
    123    * {@link #testIterator_knownOrderRemoveUnsupported()} so that tests of
    124    * {@code ArrayStack} can suppress it with
    125    * {@code FeatureSpecificTestSuiteBuilder.suppressing()}. {@code ArrayStack}
    126    * supports {@code remove()} on only the first element, and the iterator
    127    * tester can't handle that.
    128    */
    129   @GwtIncompatible("reflection")
    130   public static Method getIteratorKnownOrderRemoveUnsupportedMethod() {
    131     return Helpers.getMethod(
    132         CollectionIteratorTester.class, "testIterator_knownOrderRemoveUnsupported");
    133   }
    134 }
    135