1 //===-- Unittests for strchr ----------------------------------------------===//
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/strchr.h"
10 #include "utils/UnitTest/Test.h"
11 
12 TEST(LlvmLibcStrChrTest, FindsFirstCharacter) {
13   const char *src = "abcde";
14 
15   // Should return original string since 'a' is the first character.
16   ASSERT_STREQ(__llvm_libc::strchr(src, 'a'), "abcde");
17   // Source string should not change.
18   ASSERT_STREQ(src, "abcde");
19 }
20 
21 TEST(LlvmLibcStrChrTest, FindsMiddleCharacter) {
22   const char *src = "abcde";
23 
24   // Should return characters after (and including) 'c'.
25   ASSERT_STREQ(__llvm_libc::strchr(src, 'c'), "cde");
26   // Source string should not change.
27   ASSERT_STREQ(src, "abcde");
28 }
29 
30 TEST(LlvmLibcStrChrTest, FindsLastCharacterThatIsNotNullTerminator) {
31   const char *src = "abcde";
32 
33   // Should return 'e' and null-terminator.
34   ASSERT_STREQ(__llvm_libc::strchr(src, 'e'), "e");
35   // Source string should not change.
36   ASSERT_STREQ(src, "abcde");
37 }
38 
39 TEST(LlvmLibcStrChrTest, FindsNullTerminator) {
40   const char *src = "abcde";
41 
42   // Should return null terminator.
43   ASSERT_STREQ(__llvm_libc::strchr(src, '\0'), "");
44   // Source string should not change.
45   ASSERT_STREQ(src, "abcde");
46 }
47 
48 TEST(LlvmLibcStrChrTest, CharacterNotWithinStringShouldReturnNullptr) {
49   // Since 'z' is not within the string, should return nullptr.
50   ASSERT_STREQ(__llvm_libc::strchr("123?", 'z'), nullptr);
51 }
52 
53 TEST(LlvmLibcStrChrTest, TheSourceShouldNotChange) {
54   const char *src = "abcde";
55   // When the character is found, the source string should not change.
56   __llvm_libc::strchr(src, 'd');
57   ASSERT_STREQ(src, "abcde");
58   // Same case for when the character is not found.
59   __llvm_libc::strchr(src, 'z');
60   ASSERT_STREQ(src, "abcde");
61   // Same case for when looking for nullptr.
62   __llvm_libc::strchr(src, '\0');
63   ASSERT_STREQ(src, "abcde");
64 }
65 
66 TEST(LlvmLibcStrChrTest, ShouldFindFirstOfDuplicates) {
67   // '1' is duplicated in the string, but it should find the first copy.
68   ASSERT_STREQ(__llvm_libc::strchr("abc1def1ghi", '1'), "1def1ghi");
69 
70   const char *dups = "XXXXX";
71   // Should return original string since 'X' is the first character.
72   ASSERT_STREQ(__llvm_libc::strchr(dups, 'X'), dups);
73 }
74 
75 TEST(LlvmLibcStrChrTest, EmptyStringShouldOnlyMatchNullTerminator) {
76   // Null terminator should match.
77   ASSERT_STREQ(__llvm_libc::strchr("", '\0'), "");
78   // All other characters should not match.
79   ASSERT_STREQ(__llvm_libc::strchr("", 'Z'), nullptr);
80   ASSERT_STREQ(__llvm_libc::strchr("", '3'), nullptr);
81   ASSERT_STREQ(__llvm_libc::strchr("", '*'), nullptr);
82 }
83