| /* |
| * Copyright (C) 2016 The Guava Authors |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package com.google.common.collect; |
| |
| import static java.util.Arrays.asList; |
| import static java.util.Comparator.comparing; |
| import static java.util.Comparator.naturalOrder; |
| |
| import com.google.common.annotations.GwtCompatible; |
| import com.google.common.collect.testing.Helpers; |
| import com.google.common.testing.CollectorTester; |
| import com.google.common.testing.EqualsTester; |
| import java.util.Arrays; |
| import java.util.Collections; |
| import java.util.Comparator; |
| import java.util.Optional; |
| import junit.framework.TestCase; |
| |
| /** |
| * Tests for {@code Comparators}. |
| * |
| * @author Louis Wasserman |
| */ |
| @GwtCompatible |
| public class ComparatorsTest extends TestCase { |
| @SuppressWarnings("unchecked") // dang varargs |
| public void testLexicographical() { |
| Comparator<String> comparator = Ordering.natural(); |
| Comparator<Iterable<String>> lexy = Comparators.lexicographical(comparator); |
| |
| ImmutableList<String> empty = ImmutableList.of(); |
| ImmutableList<String> a = ImmutableList.of("a"); |
| ImmutableList<String> aa = ImmutableList.of("a", "a"); |
| ImmutableList<String> ab = ImmutableList.of("a", "b"); |
| ImmutableList<String> b = ImmutableList.of("b"); |
| |
| Helpers.testComparator(lexy, empty, a, aa, ab, b); |
| |
| new EqualsTester() |
| .addEqualityGroup(lexy, Comparators.lexicographical(comparator)) |
| .addEqualityGroup(Comparators.lexicographical(String.CASE_INSENSITIVE_ORDER)) |
| .addEqualityGroup(Ordering.natural()) |
| .testEquals(); |
| } |
| |
| public void testIsInOrder() { |
| assertFalse(Comparators.isInOrder(asList(5, 3, 0, 9), Ordering.natural())); |
| assertFalse(Comparators.isInOrder(asList(0, 5, 3, 9), Ordering.natural())); |
| assertTrue(Comparators.isInOrder(asList(0, 3, 5, 9), Ordering.natural())); |
| assertTrue(Comparators.isInOrder(asList(0, 0, 3, 3), Ordering.natural())); |
| assertTrue(Comparators.isInOrder(asList(0, 3), Ordering.natural())); |
| assertTrue(Comparators.isInOrder(Collections.singleton(1), Ordering.natural())); |
| assertTrue(Comparators.isInOrder(Collections.<Integer>emptyList(), Ordering.natural())); |
| } |
| |
| public void testIsInStrictOrder() { |
| assertFalse(Comparators.isInStrictOrder(asList(5, 3, 0, 9), Ordering.natural())); |
| assertFalse(Comparators.isInStrictOrder(asList(0, 5, 3, 9), Ordering.natural())); |
| assertTrue(Comparators.isInStrictOrder(asList(0, 3, 5, 9), Ordering.natural())); |
| assertFalse(Comparators.isInStrictOrder(asList(0, 0, 3, 3), Ordering.natural())); |
| assertTrue(Comparators.isInStrictOrder(asList(0, 3), Ordering.natural())); |
| assertTrue(Comparators.isInStrictOrder(Collections.singleton(1), Ordering.natural())); |
| assertTrue(Comparators.isInStrictOrder(Collections.<Integer>emptyList(), Ordering.natural())); |
| } |
| |
| public void testLeastCollector() { |
| CollectorTester.of(Comparators.<Integer>least(2, Comparator.naturalOrder())) |
| .expectCollects(Arrays.asList(1, 2), 1, 2, 3, 4, 5, 6) |
| .expectCollects(Arrays.asList(1), 1) |
| .expectCollects(Collections.emptyList()); |
| } |
| |
| public void testGreatestCollector() { |
| CollectorTester.of(Comparators.<Integer>greatest(2, Comparator.naturalOrder())) |
| .expectCollects(Arrays.asList(6, 5), 1, 2, 3, 4, 5, 6) |
| .expectCollects(Arrays.asList(1), 1) |
| .expectCollects(Collections.emptyList()); |
| } |
| |
| public void testEmptiesFirst() { |
| Optional<String> empty = Optional.empty(); |
| Optional<String> abc = Optional.of("abc"); |
| Optional<String> z = Optional.of("z"); |
| |
| Comparator<Optional<String>> comparator = Comparators.emptiesFirst(comparing(String::length)); |
| Helpers.testComparator(comparator, empty, z, abc); |
| |
| // Just demonstrate that no explicit type parameter is required |
| comparator = Comparators.emptiesFirst(naturalOrder()); |
| } |
| |
| public void testEmptiesLast() { |
| Optional<String> empty = Optional.empty(); |
| Optional<String> abc = Optional.of("abc"); |
| Optional<String> z = Optional.of("z"); |
| |
| Comparator<Optional<String>> comparator = Comparators.emptiesLast(comparing(String::length)); |
| Helpers.testComparator(comparator, z, abc, empty); |
| |
| // Just demonstrate that no explicit type parameter is required |
| comparator = Comparators.emptiesLast(naturalOrder()); |
| } |
| } |