1 /* 2 * Copyright (C) 2016 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; 18 19 import static com.google.common.truth.Truth.assertThat; 20 import static com.google.common.truth.Truth8.assertThat; 21 22 import com.google.common.annotations.GwtCompatible; 23 import java.util.NoSuchElementException; 24 import java.util.stream.Stream; 25 import junit.framework.TestCase; 26 27 /** 28 * Tests for {@code MoreCollectors}. 29 * 30 * @author Louis Wasserman 31 */ 32 @GwtCompatible 33 public class MoreCollectorsTest extends TestCase { testToOptionalEmpty()34 public void testToOptionalEmpty() { 35 assertThat(Stream.empty().collect(MoreCollectors.toOptional())).isEmpty(); 36 } 37 testToOptionalSingleton()38 public void testToOptionalSingleton() { 39 assertThat(Stream.of(1).collect(MoreCollectors.toOptional())).hasValue(1); 40 } 41 testToOptionalNull()42 public void testToOptionalNull() { 43 Stream<Object> stream = Stream.of((Object) null); 44 try { 45 stream.collect(MoreCollectors.toOptional()); 46 fail("Expected NullPointerException"); 47 } catch (NullPointerException expected) { 48 } 49 } 50 testToOptionalMultiple()51 public void testToOptionalMultiple() { 52 try { 53 Stream.of(1, 2).collect(MoreCollectors.toOptional()); 54 fail("Expected IllegalArgumentException"); 55 } catch (IllegalArgumentException expected) { 56 assertThat(expected.getMessage()).contains("1, 2"); 57 } 58 } 59 testToOptionalMultipleWithNull()60 public void testToOptionalMultipleWithNull() { 61 try { 62 Stream.of(1, null).collect(MoreCollectors.toOptional()); 63 fail("Expected NullPointerException"); 64 } catch (NullPointerException expected) { 65 } 66 } 67 testToOptionalMany()68 public void testToOptionalMany() { 69 try { 70 Stream.of(1, 2, 3, 4, 5, 6).collect(MoreCollectors.toOptional()); 71 fail("Expected IllegalArgumentException"); 72 } catch (IllegalArgumentException expected) { 73 assertThat(expected.getMessage()).contains("1, 2, 3, 4, 5, ..."); 74 } 75 } 76 testOnlyElement()77 public void testOnlyElement() { 78 try { 79 Stream.empty().collect(MoreCollectors.onlyElement()); 80 fail("Expected NoSuchElementException"); 81 } catch (NoSuchElementException expected) { 82 } 83 } 84 testOnlyElementSingleton()85 public void testOnlyElementSingleton() { 86 assertThat(Stream.of(1).collect(MoreCollectors.onlyElement())).isEqualTo(1); 87 } 88 testOnlyElementNull()89 public void testOnlyElementNull() { 90 assertThat(Stream.of((Object) null).collect(MoreCollectors.onlyElement())).isNull(); 91 } 92 testOnlyElementMultiple()93 public void testOnlyElementMultiple() { 94 try { 95 Stream.of(1, 2).collect(MoreCollectors.onlyElement()); 96 fail("Expected IllegalArgumentException"); 97 } catch (IllegalArgumentException expected) { 98 assertThat(expected.getMessage()).contains("1, 2"); 99 } 100 } 101 testOnlyElementMany()102 public void testOnlyElementMany() { 103 try { 104 Stream.of(1, 2, 3, 4, 5, 6).collect(MoreCollectors.onlyElement()); 105 fail("Expected IllegalArgumentException"); 106 } catch (IllegalArgumentException expected) { 107 assertThat(expected.getMessage()).contains("1, 2, 3, 4, 5, ..."); 108 } 109 } 110 } 111