libc/test/src/string/strchrnul_test.cpp

   1 //===-- Unittests for strchrnul -------------------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #include "src/string/strchrnul.h"
  10 #include "test/UnitTest/Test.h"
  11
  12 TEST(LlvmLibcStrChrNulTest, FindsFirstCharacter) {
  13   const char *src = "abcde";
  14
  15   // Should return original string since 'a' is the first character.
  16   ASSERT_STREQ(LIBC_NAMESPACE::strchrnul(src, 'a'), "abcde");
  17   // Source string should not change.
  18   ASSERT_STREQ(src, "abcde");
  19 }
  20
  21 TEST(LlvmLibcStrChrNulTest, FindsMiddleCharacter) {
  22   const char *src = "abcde";
  23
  24   // Should return characters after (and including) 'c'.
  25   ASSERT_STREQ(LIBC_NAMESPACE::strchrnul(src, 'c'), "cde");
  26   // Source string should not change.
  27   ASSERT_STREQ(src, "abcde");
  28 }
  29
  30 TEST(LlvmLibcStrChrNulTest, FindsLastCharacterThatIsNotNullTerminator) {
  31   const char *src = "abcde";
  32
  33   // Should return 'e' and null-terminator.
  34   ASSERT_STREQ(LIBC_NAMESPACE::strchrnul(src, 'e'), "e");
  35   // Source string should not change.
  36   ASSERT_STREQ(src, "abcde");
  37 }
  38
  39 TEST(LlvmLibcStrChrNulTest, FindsNullTerminator) {
  40   const char *src = "abcde";
  41
  42   // Should return null terminator.
  43   ASSERT_STREQ(LIBC_NAMESPACE::strchrnul(src, '\0'), "");
  44   // Source string should not change.
  45   ASSERT_STREQ(src, "abcde");
  46 }
  47
  48 TEST(LlvmLibcStrChrNulTest,
  49      CharacterNotWithinStringShouldReturnNullTerminator) {
  50   const char *src = "123?";
  51
  52   // Since 'z' is not within the string, should return a pointer to the source
  53   // string's null terminator.
  54   char *result = LIBC_NAMESPACE::strchrnul(src, 'z');
  55   ASSERT_EQ(*result, '\0');
  56
  57   char *term = const_cast<char *>(src) + 4;
  58   ASSERT_EQ(result, term);
  59 }
  60
  61 TEST(LlvmLibcStrChrNulTest, TheSourceShouldNotChange) {
  62   const char *src = "abcde";
  63   // When the character is found, the source string should not change.
  64   LIBC_NAMESPACE::strchrnul(src, 'd');
  65   ASSERT_STREQ(src, "abcde");
  66   // Same case for when the character is not found.
  67   LIBC_NAMESPACE::strchrnul(src, 'z');
  68   ASSERT_STREQ(src, "abcde");
  69   // Same case for when looking for null terminator.
  70   LIBC_NAMESPACE::strchrnul(src, '\0');
  71   ASSERT_STREQ(src, "abcde");
  72 }
  73
  74 TEST(LlvmLibcStrChrNulTest, ShouldFindFirstOfDuplicates) {
  75   // '1' is duplicated in the string, but it should find the first copy.
  76   ASSERT_STREQ(LIBC_NAMESPACE::strchrnul("abc1def1ghi", '1'), "1def1ghi");
  77
  78   const char *dups = "XXXXX";
  79   // Should return original string since 'X' is the first character.
  80   ASSERT_STREQ(LIBC_NAMESPACE::strchrnul(dups, 'X'), dups);
  81 }
  82
  83 TEST(LlvmLibcStrChrNulTest, EmptyStringShouldOnlyMatchNullTerminator) {
  84   // Null terminator should match.
  85   ASSERT_STREQ(LIBC_NAMESPACE::strchrnul("", '\0'), "");
  86
  87   // All other characters should not match.
  88   char *result = LIBC_NAMESPACE::strchrnul("", 'Z');
  89   ASSERT_EQ(*result, '\0');
  90
  91   result = LIBC_NAMESPACE::strchrnul("", '3');
  92   ASSERT_EQ(*result, '\0');
  93
  94   result = LIBC_NAMESPACE::strchrnul("", '*');
  95   ASSERT_EQ(*result, '\0');
  96 }