libc/test/src/stdio/scanf_core/reader_test.cpp

   1 //===-- Unittests for the scanf String Reader -----------------------------===//
   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/__support/CPP/string_view.h"
  10 #include "src/stdio/scanf_core/reader.h"
  11
  12 #include "test/UnitTest/Test.h"
  13
  14 TEST(LlvmLibcScanfStringReaderTest, Constructor) {
  15   char str[10];
  16   // buff_len justneeds to be a big number. The specific value isn't important
  17   // in the real world.
  18   LIBC_NAMESPACE::scanf_core::ReadBuffer rb{const_cast<char *>(str), 1000000};
  19   LIBC_NAMESPACE::scanf_core::Reader reader(&rb);
  20 }
  21
  22 TEST(LlvmLibcScanfStringReaderTest, SimpleRead) {
  23   const char *str = "abc";
  24   LIBC_NAMESPACE::scanf_core::ReadBuffer rb{const_cast<char *>(str), 1000000};
  25   LIBC_NAMESPACE::scanf_core::Reader reader(&rb);
  26
  27   for (size_t i = 0; i < sizeof("abc"); ++i) {
  28     ASSERT_EQ(str[i], reader.getc());
  29   }
  30 }
  31
  32 TEST(LlvmLibcScanfStringReaderTest, ReadAndReverse) {
  33   const char *str = "abcDEF123";
  34   LIBC_NAMESPACE::scanf_core::ReadBuffer rb{const_cast<char *>(str), 1000000};
  35   LIBC_NAMESPACE::scanf_core::Reader reader(&rb);
  36
  37   for (size_t i = 0; i < 5; ++i) {
  38     ASSERT_EQ(str[i], reader.getc());
  39   }
  40
  41   // Move back by 3, cursor should now be on 2
  42   reader.ungetc(str[4]);
  43   reader.ungetc(str[3]);
  44   reader.ungetc(str[2]);
  45
  46   for (size_t i = 2; i < 7; ++i) {
  47     ASSERT_EQ(str[i], reader.getc());
  48   }
  49
  50   // Move back by 2, cursor should now be on 5
  51   reader.ungetc(str[6]);
  52   reader.ungetc(str[5]);
  53
  54   for (size_t i = 5; i < 10; ++i) {
  55     ASSERT_EQ(str[i], reader.getc());
  56   }
  57
  58   // Move back by 10, which should be back to the start.
  59   for (size_t i = 0; i < 10; ++i) {
  60     reader.ungetc(str[9 - i]);
  61   }
  62
  63   // Check the whole string.
  64   for (size_t i = 0; i < sizeof("abcDEF123"); ++i) {
  65     ASSERT_EQ(str[i], reader.getc());
  66   }
  67 }