1//===-- Unittests for strstr ----------------------------------------------===//
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/strstr.h"
10#include "test/UnitTest/Test.h"
11
12TEST(LlvmLibcStrStrTest, NeedleNotInHaystack) {
13 const char *haystack = "12345";
14 const char *needle = "a";
15 ASSERT_STREQ(LIBC_NAMESPACE::strstr(haystack, needle), nullptr);
16}
17
18TEST(LlvmLibcStrStrTest, NeedleIsEmptyString) {
19 const char *haystack = "12345";
20 const char *needle = "";
21 ASSERT_STREQ(LIBC_NAMESPACE::strstr(haystack, needle), haystack);
22}
23
24TEST(LlvmLibcStrStrTest, HaystackIsEmptyString) {
25 const char *haystack = "";
26 const char *needle = "12345";
27 ASSERT_STREQ(LIBC_NAMESPACE::strstr(haystack, needle), nullptr);
28}
29
30TEST(LlvmLibcStrStrTest, HaystackAndNeedleAreEmptyStrings) {
31 const char *haystack = "";
32 const char *needle = "";
33 ASSERT_STREQ(LIBC_NAMESPACE::strstr(haystack, needle), "");
34}
35
36TEST(LlvmLibcStrStrTest, HaystackAndNeedleAreSingleCharacters) {
37 const char *haystack = "a";
38 // Same characer returns that character.
39 ASSERT_STREQ(LIBC_NAMESPACE::strstr(haystack, /*needle=*/"a"), "a");
40 // Different character returns nullptr.
41 ASSERT_STREQ(LIBC_NAMESPACE::strstr(haystack, /*needle=*/"b"), nullptr);
42}
43
44TEST(LlvmLibcStrStrTest, NeedleEqualToHaystack) {
45 const char *haystack = "12345";
46 const char *needle = "12345";
47 ASSERT_STREQ(LIBC_NAMESPACE::strstr(haystack, needle), "12345");
48}
49
50TEST(LlvmLibcStrStrTest, NeedleSmallerThanHaystack) {
51 const char *haystack = "12345";
52 const char *needle = "345";
53 ASSERT_STREQ(LIBC_NAMESPACE::strstr(haystack, needle), "345");
54}
55
56TEST(LlvmLibcStrStrTest, NeedleLargerThanHaystack) {
57 const char *haystack = "123";
58 const char *needle = "12345";
59 ASSERT_STREQ(LIBC_NAMESPACE::strstr(haystack, needle), nullptr);
60}
61
62TEST(LlvmLibcStrStrTest, NeedleAtBeginning) {
63 const char *haystack = "12345";
64 const char *needle = "12";
65 ASSERT_STREQ(LIBC_NAMESPACE::strstr(haystack, needle), "12345");
66}
67
68TEST(LlvmLibcStrStrTest, NeedleInMiddle) {
69 const char *haystack = "abcdefghi";
70 const char *needle = "def";
71 ASSERT_STREQ(LIBC_NAMESPACE::strstr(haystack, needle), "defghi");
72}
73
74TEST(LlvmLibcStrStrTest, NeedleDirectlyBeforeNullTerminator) {
75 const char *haystack = "abcdefghi";
76 const char *needle = "ghi";
77 ASSERT_STREQ(LIBC_NAMESPACE::strstr(haystack, needle), "ghi");
78}
79
80TEST(LlvmLibcStrStrTest, NeedlePastNullTerminator) {
81 const char haystack[5] = {'1', '2', '\0', '3', '4'};
82 // Shouldn't find anything after the null terminator.
83 ASSERT_STREQ(LIBC_NAMESPACE::strstr(haystack, /*needle=*/"3"), nullptr);
84 ASSERT_STREQ(LIBC_NAMESPACE::strstr(haystack, /*needle=*/"4"), nullptr);
85}
86
87TEST(LlvmLibcStrStrTest, PartialNeedle) {
88 const char *haystack = "la_ap_lap";
89 const char *needle = "lap";
90 // Shouldn't find la or ap.
91 ASSERT_STREQ(LIBC_NAMESPACE::strstr(haystack, needle), "lap");
92}
93
94TEST(LlvmLibcStrStrTest, MisspelledNeedle) {
95 const char *haystack = "atalloftwocities...wait, tale";
96 const char *needle = "tale";
97 ASSERT_STREQ(LIBC_NAMESPACE::strstr(haystack, needle), "tale");
98}
99
100TEST(LlvmLibcStrStrTest, AnagramNeedle) {
101 const char *haystack = "dgo_ogd_god_odg_gdo_dog";
102 const char *needle = "dog";
103 ASSERT_STREQ(LIBC_NAMESPACE::strstr(haystack, needle), "dog");
104}
105
106TEST(LlvmLibcStrStrTest, MorphedNeedle) {
107 // Changes a single letter in the needle to mismatch with the haystack.
108 const char *haystack = "once upon a time";
109 ASSERT_STREQ(LIBC_NAMESPACE::strstr(haystack, "time"), "time");
110 ASSERT_STREQ(LIBC_NAMESPACE::strstr(haystack, "lime"), nullptr);
111 ASSERT_STREQ(LIBC_NAMESPACE::strstr(haystack, "tome"), nullptr);
112 ASSERT_STREQ(LIBC_NAMESPACE::strstr(haystack, "tire"), nullptr);
113 ASSERT_STREQ(LIBC_NAMESPACE::strstr(haystack, "timo"), nullptr);
114}
115

source code of libc/test/src/string/strstr_test.cpp