libc/test/src/string/strnlen_test.cpp

   1 //===-- Unittests for strnlen ---------------------------------------------===//
   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/strnlen.h"
  10 #include "test/UnitTest/Test.h"
  11 #include <stddef.h>
  12
  13 TEST(LlvmLibcStrNLenTest, EmptyString) {
  14   const char *empty = "";
  15   ASSERT_EQ(static_cast<size_t>(0), LIBC_NAMESPACE::strnlen(empty, 0));
  16   // If N is greater than string length, this should still return 0.
  17   ASSERT_EQ(static_cast<size_t>(0), LIBC_NAMESPACE::strnlen(empty, 1));
  18 }
  19
  20 TEST(LlvmLibcStrNLenTest, OneCharacterString) {
  21   const char *single = "X";
  22   ASSERT_EQ(static_cast<size_t>(1), LIBC_NAMESPACE::strnlen(single, 1));
  23   // If N is zero, this should return 0.
  24   ASSERT_EQ(static_cast<size_t>(0), LIBC_NAMESPACE::strnlen(single, 0));
  25   // If N is greater than string length, this should still return 1.
  26   ASSERT_EQ(static_cast<size_t>(1), LIBC_NAMESPACE::strnlen(single, 2));
  27 }
  28
  29 TEST(LlvmLibcStrNLenTest, ManyCharacterString) {
  30   const char *many = "123456789";
  31   ASSERT_EQ(static_cast<size_t>(9), LIBC_NAMESPACE::strnlen(many, 9));
  32   // If N is smaller than the string length, it should return N.
  33   ASSERT_EQ(static_cast<size_t>(3), LIBC_NAMESPACE::strnlen(many, 3));
  34   // If N is zero, this should return 0.
  35   ASSERT_EQ(static_cast<size_t>(0), LIBC_NAMESPACE::strnlen(many, 0));
  36   // If N is greater than the string length, this should still return 9.
  37   ASSERT_EQ(static_cast<size_t>(9), LIBC_NAMESPACE::strnlen(many, 42));
  38 }
  39
  40 TEST(LlvmLibcStrNLenTest, CharactersAfterNullTerminatorShouldNotBeIncluded) {
  41   const char str[5] = {'a', 'b', 'c', '\0', 'd'};
  42   ASSERT_EQ(static_cast<size_t>(3), LIBC_NAMESPACE::strnlen(str, 3));
  43   // This should only read up to the null terminator.
  44   ASSERT_EQ(static_cast<size_t>(3), LIBC_NAMESPACE::strnlen(str, 4));
  45   ASSERT_EQ(static_cast<size_t>(3), LIBC_NAMESPACE::strnlen(str, 5));
  46 }