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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.collect.testing.AbstractCollectionTester;
     26 import com.google.common.collect.testing.Helpers;
     27 import com.google.common.collect.testing.IteratorFeature;
     28 import com.google.common.collect.testing.IteratorTester;
     29 import com.google.common.collect.testing.features.CollectionFeature;
     30 
     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 
     38 /**
     39  * A generic JUnit test which tests {@code iterator} operations on a collection.
     40  * Can't be invoked directly; please see
     41  * {@link com.google.common.collect.testing.CollectionTestSuiteBuilder}.
     42  *
     43  * @author Chris Povirk
     44  */
     45 @GwtCompatible(emulated = true)
     46 public class CollectionIteratorTester<E> extends AbstractCollectionTester<E> {
     47   public void testIterator() {
     48     List<E> iteratorElements = new ArrayList<E>();
     49     for (E element : collection) { // uses iterator()
     50       iteratorElements.add(element);
     51     }
     52     Helpers.assertEqualIgnoringOrder(
     53         Arrays.asList(createSamplesArray()), iteratorElements);
     54   }
     55 
     56   @CollectionFeature.Require(KNOWN_ORDER)
     57   public void testIterationOrdering() {
     58     List<E> iteratorElements = new ArrayList<E>();
     59     for (E element : collection) { // uses iterator()
     60       iteratorElements.add(element);
     61     }
     62     List<E> expected = Helpers.copyToList(getOrderedElements());
     63     assertEquals("Different ordered iteration", expected, iteratorElements);
     64   }
     65 
     66   // TODO: switch to DerivedIteratorTestSuiteBuilder
     67 
     68   @CollectionFeature.Require({KNOWN_ORDER, SUPPORTS_ITERATOR_REMOVE})
     69   public void testIterator_knownOrderRemoveSupported() {
     70     runIteratorTest(MODIFIABLE, IteratorTester.KnownOrder.KNOWN_ORDER,
     71         getOrderedElements());
     72   }
     73 
     74   @CollectionFeature.Require(value = KNOWN_ORDER, absent = SUPPORTS_ITERATOR_REMOVE)
     75   public void testIterator_knownOrderRemoveUnsupported() {
     76     runIteratorTest(UNMODIFIABLE, IteratorTester.KnownOrder.KNOWN_ORDER,
     77         getOrderedElements());
     78   }
     79 
     80   @CollectionFeature.Require(absent = KNOWN_ORDER, value = SUPPORTS_ITERATOR_REMOVE)
     81   public void testIterator_unknownOrderRemoveSupported() {
     82     runIteratorTest(MODIFIABLE, IteratorTester.KnownOrder.UNKNOWN_ORDER,
     83         getSampleElements());
     84   }
     85 
     86   @CollectionFeature.Require(absent = {KNOWN_ORDER, SUPPORTS_ITERATOR_REMOVE})
     87   public void testIterator_unknownOrderRemoveUnsupported() {
     88     runIteratorTest(UNMODIFIABLE, IteratorTester.KnownOrder.UNKNOWN_ORDER,
     89         getSampleElements());
     90   }
     91 
     92   private void runIteratorTest(Set<IteratorFeature> features,
     93       IteratorTester.KnownOrder knownOrder, Iterable<E> elements) {
     94     new IteratorTester<E>(Platform.collectionIteratorTesterNumIterations(), features, elements,
     95         knownOrder) {
     96       @Override protected Iterator<E> newTargetIterator() {
     97         resetCollection();
     98         return collection.iterator();
     99       }
    100 
    101       @Override protected void verify(List<E> elements) {
    102         expectContents(elements);
    103       }
    104     }.test();
    105   }
    106 
    107   public void testIteratorNoSuchElementException() {
    108     Iterator<E> iterator = collection.iterator();
    109     while (iterator.hasNext()) {
    110       iterator.next();
    111     }
    112 
    113     try {
    114       iterator.next();
    115       fail("iterator.next() should throw NoSuchElementException");
    116     } catch (NoSuchElementException expected) {}
    117   }
    118 }
    119 
    120