1 /* 2 * Copyright (C) 2010 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.base; 18 19 import com.google.common.annotations.GwtCompatible; 20 import com.google.common.annotations.GwtIncompatible; 21 import com.google.common.testing.NullPointerTester; 22 23 import junit.framework.TestCase; 24 25 /** 26 * Unit test for {@link Strings}. 27 * 28 * @author Kevin Bourrillion 29 */ 30 @GwtCompatible(emulated = true) 31 public class StringsTest extends TestCase { testNullToEmpty()32 public void testNullToEmpty() { 33 assertEquals("", Strings.nullToEmpty(null)); 34 assertEquals("", Strings.nullToEmpty("")); 35 assertEquals("a", Strings.nullToEmpty("a")); 36 } 37 testEmptyToNull()38 public void testEmptyToNull() { 39 assertNull(Strings.emptyToNull(null)); 40 assertNull(Strings.emptyToNull("")); 41 assertEquals("a", Strings.emptyToNull("a")); 42 } 43 testIsNullOrEmpty()44 public void testIsNullOrEmpty() { 45 assertTrue(Strings.isNullOrEmpty(null)); 46 assertTrue(Strings.isNullOrEmpty("")); 47 assertFalse(Strings.isNullOrEmpty("a")); 48 } 49 testPadStart_noPadding()50 public void testPadStart_noPadding() { 51 assertSame("", Strings.padStart("", 0, '-')); 52 assertSame("x", Strings.padStart("x", 0, '-')); 53 assertSame("x", Strings.padStart("x", 1, '-')); 54 assertSame("xx", Strings.padStart("xx", 0, '-')); 55 assertSame("xx", Strings.padStart("xx", 2, '-')); 56 } 57 testPadStart_somePadding()58 public void testPadStart_somePadding() { 59 assertEquals("-", Strings.padStart("", 1, '-')); 60 assertEquals("--", Strings.padStart("", 2, '-')); 61 assertEquals("-x", Strings.padStart("x", 2, '-')); 62 assertEquals("--x", Strings.padStart("x", 3, '-')); 63 assertEquals("-xx", Strings.padStart("xx", 3, '-')); 64 } 65 testPadStart_negativeMinLength()66 public void testPadStart_negativeMinLength() { 67 assertSame("x", Strings.padStart("x", -1, '-')); 68 } 69 70 // TODO: could remove if we got NPT working in GWT somehow testPadStart_null()71 public void testPadStart_null() { 72 try { 73 Strings.padStart(null, 5, '0'); 74 fail(); 75 } catch (NullPointerException expected) { 76 } 77 } 78 testPadEnd_noPadding()79 public void testPadEnd_noPadding() { 80 assertSame("", Strings.padEnd("", 0, '-')); 81 assertSame("x", Strings.padEnd("x", 0, '-')); 82 assertSame("x", Strings.padEnd("x", 1, '-')); 83 assertSame("xx", Strings.padEnd("xx", 0, '-')); 84 assertSame("xx", Strings.padEnd("xx", 2, '-')); 85 } 86 testPadEnd_somePadding()87 public void testPadEnd_somePadding() { 88 assertEquals("-", Strings.padEnd("", 1, '-')); 89 assertEquals("--", Strings.padEnd("", 2, '-')); 90 assertEquals("x-", Strings.padEnd("x", 2, '-')); 91 assertEquals("x--", Strings.padEnd("x", 3, '-')); 92 assertEquals("xx-", Strings.padEnd("xx", 3, '-')); 93 } 94 testPadEnd_negativeMinLength()95 public void testPadEnd_negativeMinLength() { 96 assertSame("x", Strings.padEnd("x", -1, '-')); 97 } 98 99 // TODO: could remove if we got NPT working in GWT somehow testPadEnd_null()100 public void testPadEnd_null() { 101 try { 102 Strings.padEnd(null, 5, '0'); 103 fail(); 104 } catch (NullPointerException expected) { 105 } 106 } 107 testRepeat()108 public void testRepeat() { 109 String input = "20"; 110 assertEquals("", Strings.repeat(input, 0)); 111 assertEquals("20", Strings.repeat(input, 1)); 112 assertEquals("2020", Strings.repeat(input, 2)); 113 assertEquals("202020", Strings.repeat(input, 3)); 114 115 assertEquals("", Strings.repeat("", 4)); 116 117 for (int i = 0; i < 100; ++i) { 118 assertEquals(2 * i, Strings.repeat(input, i).length()); 119 } 120 121 try { 122 Strings.repeat("x", -1); 123 fail(); 124 } catch (IllegalArgumentException expected) { 125 } 126 try { 127 // Massive string 128 Strings.repeat("12345678", (1 << 30) + 3); 129 fail(); 130 } catch (ArrayIndexOutOfBoundsException expected) { 131 } 132 } 133 134 // TODO: could remove if we got NPT working in GWT somehow testRepeat_null()135 public void testRepeat_null() { 136 try { 137 Strings.repeat(null, 5); 138 fail(); 139 } catch (NullPointerException expected) { 140 } 141 } 142 testCommonPrefix()143 public void testCommonPrefix() { 144 assertEquals("", Strings.commonPrefix("", "")); 145 assertEquals("", Strings.commonPrefix("abc", "")); 146 assertEquals("", Strings.commonPrefix("", "abc")); 147 assertEquals("", Strings.commonPrefix("abcde", "xyz")); 148 assertEquals("", Strings.commonPrefix("xyz", "abcde")); 149 assertEquals("", Strings.commonPrefix("xyz", "abcxyz")); 150 assertEquals("a", Strings.commonPrefix("abc", "aaaaa")); 151 assertEquals("aa", Strings.commonPrefix("aa", "aaaaa")); 152 assertEquals("abc", 153 Strings.commonPrefix(new StringBuffer("abcdef"), "abcxyz")); 154 155 // Identical valid surrogate pairs. 156 assertEquals("abc\uD8AB\uDCAB", 157 Strings.commonPrefix("abc\uD8AB\uDCABdef", "abc\uD8AB\uDCABxyz")); 158 // Differing valid surrogate pairs. 159 assertEquals("abc", 160 Strings.commonPrefix("abc\uD8AB\uDCABdef", "abc\uD8AB\uDCACxyz")); 161 // One invalid pair. 162 assertEquals("abc", 163 Strings.commonPrefix("abc\uD8AB\uDCABdef", "abc\uD8AB\uD8ABxyz")); 164 // Two identical invalid pairs. 165 assertEquals("abc\uD8AB\uD8AC", 166 Strings.commonPrefix("abc\uD8AB\uD8ACdef", "abc\uD8AB\uD8ACxyz")); 167 // Two differing invalid pairs. 168 assertEquals("abc\uD8AB", 169 Strings.commonPrefix("abc\uD8AB\uD8ABdef", "abc\uD8AB\uD8ACxyz")); 170 // One orphan high surrogate. 171 assertEquals("", Strings.commonPrefix("\uD8AB\uDCAB", "\uD8AB")); 172 // Two orphan high surrogates. 173 assertEquals("\uD8AB", Strings.commonPrefix("\uD8AB", "\uD8AB")); 174 } 175 testCommonSuffix()176 public void testCommonSuffix() { 177 assertEquals("", Strings.commonSuffix("", "")); 178 assertEquals("", Strings.commonSuffix("abc", "")); 179 assertEquals("", Strings.commonSuffix("", "abc")); 180 assertEquals("", Strings.commonSuffix("abcde", "xyz")); 181 assertEquals("", Strings.commonSuffix("xyz", "abcde")); 182 assertEquals("", Strings.commonSuffix("xyz", "xyzabc")); 183 assertEquals("c", Strings.commonSuffix("abc", "ccccc")); 184 assertEquals("aa", Strings.commonSuffix("aa", "aaaaa")); 185 assertEquals("abc", 186 Strings.commonSuffix(new StringBuffer("xyzabc"), "xxxabc")); 187 188 // Identical valid surrogate pairs. 189 assertEquals("\uD8AB\uDCABdef", 190 Strings.commonSuffix("abc\uD8AB\uDCABdef", "xyz\uD8AB\uDCABdef")); 191 // Differing valid surrogate pairs. 192 assertEquals("def", 193 Strings.commonSuffix("abc\uD8AB\uDCABdef", "abc\uD8AC\uDCABdef")); 194 // One invalid pair. 195 assertEquals("def", 196 Strings.commonSuffix("abc\uD8AB\uDCABdef", "xyz\uDCAB\uDCABdef")); 197 // Two identical invalid pairs. 198 assertEquals("\uD8AB\uD8ABdef", 199 Strings.commonSuffix("abc\uD8AB\uD8ABdef", "xyz\uD8AB\uD8ABdef")); 200 // Two differing invalid pairs. 201 assertEquals("\uDCABdef", 202 Strings.commonSuffix("abc\uDCAB\uDCABdef", "abc\uDCAC\uDCABdef")); 203 // One orphan low surrogate. 204 assertEquals("", Strings.commonSuffix("x\uD8AB\uDCAB", "\uDCAB")); 205 // Two orphan low surrogates. 206 assertEquals("\uDCAB", Strings.commonSuffix("\uDCAB", "\uDCAB")); 207 } 208 testValidSurrogatePairAt()209 public void testValidSurrogatePairAt() { 210 assertTrue(Strings.validSurrogatePairAt("\uD8AB\uDCAB", 0)); 211 assertTrue(Strings.validSurrogatePairAt("abc\uD8AB\uDCAB", 3)); 212 assertTrue(Strings.validSurrogatePairAt("abc\uD8AB\uDCABxyz", 3)); 213 assertFalse(Strings.validSurrogatePairAt("\uD8AB\uD8AB", 0)); 214 assertFalse(Strings.validSurrogatePairAt("\uDCAB\uDCAB", 0)); 215 assertFalse(Strings.validSurrogatePairAt("\uD8AB\uDCAB", -1)); 216 assertFalse(Strings.validSurrogatePairAt("\uD8AB\uDCAB", 1)); 217 assertFalse(Strings.validSurrogatePairAt("\uD8AB\uDCAB", -2)); 218 assertFalse(Strings.validSurrogatePairAt("\uD8AB\uDCAB", 2)); 219 assertFalse(Strings.validSurrogatePairAt("x\uDCAB", 0)); 220 assertFalse(Strings.validSurrogatePairAt("\uD8ABx", 0)); 221 } 222 223 @GwtIncompatible("NullPointerTester") testNullPointers()224 public void testNullPointers() throws Exception { 225 NullPointerTester tester = new NullPointerTester(); 226 tester.testAllPublicStaticMethods(Strings.class); 227 } 228 } 229