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
17package com.google.common.collect.testing.testers;
18
19import com.google.common.collect.testing.AbstractCollectionTester;
20import com.google.common.collect.testing.Helpers;
21
22import java.util.Collection;
23import java.util.List;
24
25/**
26 * Base class for list testers.
27 *
28 * <p>This class is GWT compatible.
29 *
30 * @author George van den Driessche
31 */
32public class AbstractListTester<E> extends AbstractCollectionTester<E> {
33  /*
34   * Previously we had a field named list that was initialized to the value of
35   * collection in setUp(), but that caused problems when a tester changed the
36   * value of list or collection but not both.
37   */
38  protected final List<E> getList() {
39    return (List<E>) collection;
40  }
41
42  /**
43   * {@inheritDoc}
44   * <p>
45   * The {@code AbstractListTester} implementation overrides
46   * {@link AbstractCollectionTester#expectContents(Collection)} to verify that
47   * the order of the elements in the list under test matches what is expected.
48   */
49  @Override protected void expectContents(Collection<E> expectedCollection) {
50    List<E> expectedList = Helpers.copyToList(expectedCollection);
51    // Avoid expectEquals() here to delay reason manufacture until necessary.
52    if (getList().size() != expectedList.size()) {
53      fail("size mismatch: " + reportContext(expectedList));
54    }
55    for (int i = 0; i < expectedList.size(); i++) {
56      E expected = expectedList.get(i);
57      E actual = getList().get(i);
58      if (expected != actual &&
59          (expected == null || !expected.equals(actual))) {
60        fail("mismatch at index " + i + ": " + reportContext(expectedList));
61      }
62    }
63  }
64
65  /**
66   * Used to delay string formatting until actually required, as it
67   * otherwise shows up in the test execution profile when running an
68   * extremely large numbers of tests.
69   */
70  private String reportContext(List<E> expected) {
71    return Platform.format("expected collection %s; actual collection %s",
72                           expected, this.collection);
73  }
74}
75