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 static com.google.common.collect.testing.Helpers.copyToList;
020
021import com.google.common.annotations.GwtCompatible;
022import com.google.common.collect.testing.AbstractCollectionTester;
023import java.util.Collection;
024import java.util.List;
025import org.jspecify.annotations.NullMarked;
026import org.jspecify.annotations.Nullable;
027import org.junit.Ignore;
028
029/**
030 * Base class for list testers.
031 *
032 * @author George van den Driessche
033 */
034@GwtCompatible
035@NullMarked
036@Ignore("test runners must not instantiate and run this directly, only via suites we build")
037// @Ignore affects the Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.
038@SuppressWarnings("JUnit4ClassUsedInJUnit3")
039public class AbstractListTester<E extends @Nullable Object> extends AbstractCollectionTester<E> {
040  /*
041   * Previously we had a field named list that was initialized to the value of
042   * collection in setUp(), but that caused problems when a tester changed the
043   * value of list or collection but not both.
044   */
045  protected final List<E> getList() {
046    return (List<E>) collection;
047  }
048
049  /**
050   * {@inheritDoc}
051   *
052   * <p>The {@code AbstractListTester} implementation overrides {@link
053   * AbstractCollectionTester#expectContents(Collection)} to verify that the order of the elements
054   * in the list under test matches what is expected.
055   */
056  @Override
057  protected void expectContents(Collection<E> expectedCollection) {
058    List<E> expectedList = copyToList(expectedCollection);
059    // Avoid expectEquals() here to delay reason manufacture until necessary.
060    if (getList().size() != expectedList.size()) {
061      fail("size mismatch: " + reportContext(expectedList));
062    }
063    for (int i = 0; i < expectedList.size(); i++) {
064      E expected = expectedList.get(i);
065      E actual = getList().get(i);
066      if (expected != actual && (expected == null || !expected.equals(actual))) {
067        fail("mismatch at index " + i + ": " + reportContext(expectedList));
068      }
069    }
070  }
071
072  /**
073   * Used to delay string formatting until actually required, as it otherwise shows up in the test
074   * execution profile when running an extremely large numbers of tests.
075   */
076  private String reportContext(List<E> expected) {
077    return Platform.format(
078        "expected collection %s; actual collection %s", expected, this.collection);
079  }
080}