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 com.google.common.annotations.GwtCompatible;
020import com.google.common.collect.testing.AbstractCollectionTester;
021import com.google.common.collect.testing.Helpers;
022import java.util.Collection;
023import java.util.List;
024
025/**
026 * Base class for list testers.
027 *
028 * @author George van den Driessche
029 */
030@GwtCompatible
031public class AbstractListTester<E> extends AbstractCollectionTester<E> {
032  /*
033   * Previously we had a field named list that was initialized to the value of
034   * collection in setUp(), but that caused problems when a tester changed the
035   * value of list or collection but not both.
036   */
037  protected final List<E> getList() {
038    return (List<E>) collection;
039  }
040
041  /**
042   * {@inheritDoc}
043   *
044   * <p>The {@code AbstractListTester} implementation overrides {@link
045   * AbstractCollectionTester#expectContents(Collection)} to verify that the order of the elements
046   * in the list under test matches what is expected.
047   */
048  @Override
049  protected void expectContents(Collection<E> expectedCollection) {
050    List<E> expectedList = Helpers.copyToList(expectedCollection);
051    // Avoid expectEquals() here to delay reason manufacture until necessary.
052    if (getList().size() != expectedList.size()) {
053      fail("size mismatch: " + reportContext(expectedList));
054    }
055    for (int i = 0; i < expectedList.size(); i++) {
056      E expected = expectedList.get(i);
057      E actual = getList().get(i);
058      if (expected != actual && (expected == null || !expected.equals(actual))) {
059        fail("mismatch at index " + i + ": " + reportContext(expectedList));
060      }
061    }
062  }
063
064  /**
065   * Used to delay string formatting until actually required, as it otherwise shows up in the test
066   * execution profile when running an extremely large numbers of tests.
067   */
068  private String reportContext(List<E> expected) {
069    return Platform.format(
070        "expected collection %s; actual collection %s", expected, this.collection);
071  }
072}