base/string_util_unittest.cc

// Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include <math.h>
#include <stdarg.h>

#include <limits>
#include <sstream>

#include "base/basictypes.h"
#include "base/string_util.h"
#include "testing/gtest/include/gtest/gtest.h"

namespace {
}

static const struct trim_case {
  const wchar_t* input;
  const TrimPositions positions;
  const wchar_t* output;
  const TrimPositions return_value;
} trim_cases[] = {
  {L" Google Video ", TRIM_LEADING, L"Google Video ", TRIM_LEADING},
  {L" Google Video ", TRIM_TRAILING, L" Google Video", TRIM_TRAILING},
  {L" Google Video ", TRIM_ALL, L"Google Video", TRIM_ALL},
  {L"Google Video", TRIM_ALL, L"Google Video", TRIM_NONE},
  {L"", TRIM_ALL, L"", TRIM_NONE},
  {L"  ", TRIM_LEADING, L"", TRIM_LEADING},
  {L"  ", TRIM_TRAILING, L"", TRIM_TRAILING},
  {L"  ", TRIM_ALL, L"", TRIM_ALL},
  {L"\t\rTest String\n", TRIM_ALL, L"Test String", TRIM_ALL},
  {L"\x2002Test String\x00A0\x3000", TRIM_ALL, L"Test String", TRIM_ALL},
};

static const struct trim_case_ascii {
  const char* input;
  const TrimPositions positions;
  const char* output;
  const TrimPositions return_value;
} trim_cases_ascii[] = {
  {" Google Video ", TRIM_LEADING, "Google Video ", TRIM_LEADING},
  {" Google Video ", TRIM_TRAILING, " Google Video", TRIM_TRAILING},
  {" Google Video ", TRIM_ALL, "Google Video", TRIM_ALL},
  {"Google Video", TRIM_ALL, "Google Video", TRIM_NONE},
  {"", TRIM_ALL, "", TRIM_NONE},
  {"  ", TRIM_LEADING, "", TRIM_LEADING},
  {"  ", TRIM_TRAILING, "", TRIM_TRAILING},
  {"  ", TRIM_ALL, "", TRIM_ALL},
  {"\t\rTest String\n", TRIM_ALL, "Test String", TRIM_ALL},
};

TEST(StringUtilTest, TrimWhitespace) {
  std::wstring output;  // Allow contents to carry over to next testcase
  for (size_t i = 0; i < arraysize(trim_cases); ++i) {
    const trim_case& value = trim_cases[i];
    EXPECT_EQ(value.return_value,
              TrimWhitespace(value.input, value.positions, &output));
    EXPECT_EQ(value.output, output);
  }

  // Test that TrimWhitespace() can take the same string for input and output
  output = L"  This is a test \r\n";
  EXPECT_EQ(TRIM_ALL, TrimWhitespace(output, TRIM_ALL, &output));
  EXPECT_EQ(L"This is a test", output);

  // Once more, but with a string of whitespace
  output = L"  \r\n";
  EXPECT_EQ(TRIM_ALL, TrimWhitespace(output, TRIM_ALL, &output));
  EXPECT_EQ(L"", output);

  std::string output_ascii;
  for (size_t i = 0; i < arraysize(trim_cases_ascii); ++i) {
    const trim_case_ascii& value = trim_cases_ascii[i];
    EXPECT_EQ(value.return_value,
              TrimWhitespace(value.input, value.positions, &output_ascii));
    EXPECT_EQ(value.output, output_ascii);
  }
}

static const struct trim_case_utf8 {
  const char* input;
  const TrimPositions positions;
  const char* output;
  const TrimPositions return_value;
} trim_cases_utf8[] = {
  // UTF-8 strings that start (and end) with Unicode space characters
  // (including zero-width spaces).
  {"\xE2\x80\x80Test String\xE2\x80\x81", TRIM_ALL, "Test String", TRIM_ALL},
  {"\xE2\x80\x82Test String\xE2\x80\x83", TRIM_ALL, "Test String", TRIM_ALL},
  {"\xE2\x80\x84Test String\xE2\x80\x85", TRIM_ALL, "Test String", TRIM_ALL},
  {"\xE2\x80\x86Test String\xE2\x80\x87", TRIM_ALL, "Test String", TRIM_ALL},
  {"\xE2\x80\x88Test String\xE2\x80\x8A", TRIM_ALL, "Test String", TRIM_ALL},
  {"\xE3\x80\x80Test String\xE3\x80\x80", TRIM_ALL, "Test String", TRIM_ALL},
  // UTF-8 strings that end with 0x85 (NEL in ISO-8859).
  {"\xD0\x85", TRIM_TRAILING, "\xD0\x85", TRIM_NONE},
  {"\xD9\x85", TRIM_TRAILING, "\xD9\x85", TRIM_NONE},
  {"\xEC\x97\x85", TRIM_TRAILING, "\xEC\x97\x85", TRIM_NONE},
  {"\xF0\x90\x80\x85", TRIM_TRAILING, "\xF0\x90\x80\x85", TRIM_NONE},
  // UTF-8 strings that end with 0xA0 (non-break space in ISO-8859-1).
  {"\xD0\xA0", TRIM_TRAILING, "\xD0\xA0", TRIM_NONE},
  {"\xD9\xA0", TRIM_TRAILING, "\xD9\xA0", TRIM_NONE},
  {"\xEC\x97\xA0", TRIM_TRAILING, "\xEC\x97\xA0", TRIM_NONE},
  {"\xF0\x90\x80\xA0", TRIM_TRAILING, "\xF0\x90\x80\xA0", TRIM_NONE},
};

TEST(StringUtilTest, TrimWhitespaceUTF8) {
  std::string output_ascii;
  for (size_t i = 0; i < arraysize(trim_cases_ascii); ++i) {
    const trim_case_ascii& value = trim_cases_ascii[i];
    EXPECT_EQ(value.return_value,
              TrimWhitespaceASCII(value.input, value.positions, &output_ascii));
    EXPECT_EQ(value.output, output_ascii);
  }

  // Test that TrimWhiteSpaceUTF8() can remove Unicode space characters and
  // prevent from removing UTF-8 characters that end with an ISO-8859 NEL.
  std::string output_utf8;
  for (size_t i = 0; i < arraysize(trim_cases_utf8); ++i) {
    const trim_case_utf8& value = trim_cases_utf8[i];
    EXPECT_EQ(value.return_value,
              TrimWhitespaceUTF8(value.input, value.positions, &output_utf8));
    EXPECT_EQ(value.output, output_utf8);
  }
}

static const struct collapse_case {
  const wchar_t* input;
  const bool trim;
  const wchar_t* output;
} collapse_cases[] = {
  {L" Google Video ", false, L"Google Video"},
  {L"Google Video", false, L"Google Video"},
  {L"", false, L""},
  {L"  ", false, L""},
  {L"\t\rTest String\n", false, L"Test String"},
  {L"\x2002Test String\x00A0\x3000", false, L"Test String"},
  {L"    Test     \n  \t String    ", false, L"Test String"},
  {L"\x2002Test\x1680 \x2028 \tString\x00A0\x3000", false, L"Test String"},
  {L"   Test String", false, L"Test String"},
  {L"Test String    ", false, L"Test String"},
  {L"Test String", false, L"Test String"},
  {L"", true, L""},
  {L"\n", true, L""},
  {L"  \r  ", true, L""},
  {L"\nFoo", true, L"Foo"},
  {L"\r  Foo  ", true, L"Foo"},
  {L" Foo bar ", true, L"Foo bar"},
  {L"  \tFoo  bar  \n", true, L"Foo bar"},
  {L" a \r b\n c \r\n d \t\re \t f \n ", true, L"abcde f"},
};

TEST(StringUtilTest, CollapseWhitespace) {
  for (size_t i = 0; i < arraysize(collapse_cases); ++i) {
    const collapse_case& value = collapse_cases[i];
    EXPECT_EQ(value.output, CollapseWhitespace(value.input, value.trim));
  }
}

static const struct collapse_case_ascii {
  const char* input;
  const bool trim;
  const char* output;
} collapse_cases_ascii[] = {
  {" Google Video ", false, "Google Video"},
  {"Google Video", false, "Google Video"},
  {"", false, ""},
  {"  ", false, ""},
  {"\t\rTest String\n", false, "Test String"},
  {"    Test     \n  \t String    ", false, "Test String"},
  {"   Test String", false, "Test String"},
  {"Test String    ", false, "Test String"},
  {"Test String", false, "Test String"},
  {"", true, ""},
  {"\n", true, ""},
  {"  \r  ", true, ""},
  {"\nFoo", true, "Foo"},
  {"\r  Foo  ", true, "Foo"},
  {" Foo bar ", true, "Foo bar"},
  {"  \tFoo  bar  \n", true, "Foo bar"},
  {" a \r b\n c \r\n d \t\re \t f \n ", true, "abcde f"},
};

TEST(StringUtilTest, CollapseWhitespaceASCII) {
  for (size_t i = 0; i < arraysize(collapse_cases_ascii); ++i) {
    const collapse_case_ascii& value = collapse_cases_ascii[i];
    EXPECT_EQ(value.output, CollapseWhitespaceASCII(value.input, value.trim));
  }
}

TEST(StringUtilTest, IsStringUTF8) {
  EXPECT_TRUE(IsStringUTF8("abc"));
  EXPECT_TRUE(IsStringUTF8("\xc2\x81"));
  EXPECT_TRUE(IsStringUTF8("\xe1\x80\xbf"));
  EXPECT_TRUE(IsStringUTF8("\xf1\x80\xa0\xbf"));
  EXPECT_TRUE(IsStringUTF8("a\xc2\x81\xe1\x80\xbf\xf1\x80\xa0\xbf"));
  EXPECT_TRUE(IsStringUTF8("\xef\xbb\xbf" "abc")); // UTF-8 BOM

  // surrogate code points
  EXPECT_FALSE(IsStringUTF8("\xed\xa0\x80\xed\xbf\xbf"));
  EXPECT_FALSE(IsStringUTF8("\xed\xa0\x8f"));
  EXPECT_FALSE(IsStringUTF8("\xed\xbf\xbf"));

  // overlong sequences
  EXPECT_FALSE(IsStringUTF8("\xc0\x80")); // U+0000
  EXPECT_FALSE(IsStringUTF8("\xc1\x80\xc1\x81")); // "AB"
  EXPECT_FALSE(IsStringUTF8("\xe0\x80\x80")); // U+0000
  EXPECT_FALSE(IsStringUTF8("\xe0\x82\x80")); // U+0080
  EXPECT_FALSE(IsStringUTF8("\xe0\x9f\xbf")); // U+07ff
  EXPECT_FALSE(IsStringUTF8("\xf0\x80\x80\x8D")); // U+000D
  EXPECT_FALSE(IsStringUTF8("\xf0\x80\x82\x91")); // U+0091
  EXPECT_FALSE(IsStringUTF8("\xf0\x80\xa0\x80")); // U+0800
  EXPECT_FALSE(IsStringUTF8("\xf0\x8f\xbb\xbf")); // U+FEFF (BOM)
  EXPECT_FALSE(IsStringUTF8("\xf8\x80\x80\x80\xbf")); // U+003F
  EXPECT_FALSE(IsStringUTF8("\xfc\x80\x80\x80\xa0\xa5")); // U+00A5

  // Beyond U+10FFFF (the upper limit of Unicode codespace)
  EXPECT_FALSE(IsStringUTF8("\xf4\x90\x80\x80")); // U+110000
  EXPECT_FALSE(IsStringUTF8("\xf8\xa0\xbf\x80\xbf")); // 5 bytes
  EXPECT_FALSE(IsStringUTF8("\xfc\x9c\xbf\x80\xbf\x80")); // 6 bytes

  // BOMs in UTF-16(BE|LE) and UTF-32(BE|LE)
  EXPECT_FALSE(IsStringUTF8("\xfe\xff"));
  EXPECT_FALSE(IsStringUTF8("\xff\xfe"));
  EXPECT_FALSE(IsStringUTF8(std::string("\x00\x00\xfe\xff", 4)));
  EXPECT_FALSE(IsStringUTF8("\xff\xfe\x00\x00"));

  // Non-characters : U+xxFFF[EF] where xx is 0x00 through 0x10 and <FDD0,FDEF>
  EXPECT_FALSE(IsStringUTF8("\xef\xbf\xbe")); // U+FFFE)
  EXPECT_FALSE(IsStringUTF8("\xf0\x8f\xbf\xbe")); // U+1FFFE
  EXPECT_FALSE(IsStringUTF8("\xf3\xbf\xbf\xbf")); // U+10FFFF

  // This should also be false, but currently we pass them through.
  // Disable them for now.
#if 0
  EXPECT_FALSE(IsStringUTF8("\xef\xb7\x90")); // U+FDD0
  EXPECT_FALSE(IsStringUTF8("\xef\xb7\xaf")); // U+FDEF
#endif

  // Strings in legacy encodings. We can certainly make up strings
  // in a legacy encoding that are valid in UTF-8, but in real data,
  // most of them are invalid as UTF-8.
  EXPECT_FALSE(IsStringUTF8("caf\xe9")); // cafe with U+00E9 in ISO-8859-1
  EXPECT_FALSE(IsStringUTF8("\xb0\xa1\xb0\xa2")); // U+AC00, U+AC001 in EUC-KR
  EXPECT_FALSE(IsStringUTF8("\xa7\x41\xa6\x6e")); // U+4F60 U+597D in Big5
  // "abc" with U+201[CD] in windows-125[0-8]
  EXPECT_FALSE(IsStringUTF8("\x93" "abc\x94"));
  // U+0639 U+064E U+0644 U+064E in ISO-8859-6
  EXPECT_FALSE(IsStringUTF8("\xd9\xee\xe4\xee"));
  // U+03B3 U+03B5 U+03B9 U+03AC in ISO-8859-7
  EXPECT_FALSE(IsStringUTF8("\xe3\xe5\xe9\xdC"));
}

static const wchar_t* const kConvertRoundtripCases[] = {
  L"Google Video",
  // "网页 图片 资讯更多 »"
  L"\x7f51\x9875\x0020\x56fe\x7247\x0020\x8d44\x8baf\x66f4\x591a\x0020\x00bb",
  //  "Παγκόσμιος Ιστός"
  L"\x03a0\x03b1\x03b3\x03ba\x03cc\x03c3\x03bc\x03b9"
  L"\x03bf\x03c2\x0020\x0399\x03c3\x03c4\x03cc\x03c2",
  // "Поиск страниц на русском"
  L"\x041f\x043e\x0438\x0441\x043a\x0020\x0441\x0442"
  L"\x0440\x0430\x043d\x0438\x0446\x0020\x043d\x0430"
  L"\x0020\x0440\x0443\x0441\x0441\x043a\x043e\x043c",
  // "전체서비스"
  L"\xc804\xccb4\xc11c\xbe44\xc2a4",

  // Test characters that take more than 16 bits. This will depend on whether
  // wchar_t is 16 or 32 bits.
#if defined(WCHAR_T_IS_UTF16)
  L"\xd800\xdf00",
  // ?????  (Mathematical Alphanumeric Symbols (U+011d40 - U+011d44 : A,B,C,D,E)
  L"\xd807\xdd40\xd807\xdd41\xd807\xdd42\xd807\xdd43\xd807\xdd44",
#elif defined(WCHAR_T_IS_UTF32)
  L"\x10300",
  // ?????  (Mathematical Alphanumeric Symbols (U+011d40 - U+011d44 : A,B,C,D,E)
  L"\x11d40\x11d41\x11d42\x11d43\x11d44",
#endif
};

TEST(StringUtilTest, ConvertUTF8AndWide) {
  // we round-trip all the wide strings through UTF-8 to make sure everything
  // agrees on the conversion. This uses the stream operators to test them
  // simultaneously.
  for (size_t i = 0; i < arraysize(kConvertRoundtripCases); ++i) {
    std::ostringstream utf8;
    utf8 << WideToUTF8(kConvertRoundtripCases[i]);
    std::wostringstream wide;
    wide << UTF8ToWide(utf8.str());

    EXPECT_EQ(kConvertRoundtripCases[i], wide.str());
  }
}

TEST(StringUtilTest, ConvertUTF8AndWideEmptyString) {
  // An empty std::wstring should be converted to an empty std::string,
  // and vice versa.
  std::wstring wempty;
  std::string empty;
  EXPECT_EQ(empty, WideToUTF8(wempty));
  EXPECT_EQ(wempty, UTF8ToWide(empty));
}

TEST(StringUtilTest, ConvertUTF8ToWide) {
  struct UTF8ToWideCase {
    const char* utf8;
    const wchar_t* wide;
    bool success;
  } convert_cases[] = {
    // Regular UTF-8 input.
    {"\xe4\xbd\xa0\xe5\xa5\xbd", L"\x4f60\x597d", true},
    // Invalid Unicode code point.
    {"\xef\xbf\xbfHello", L"Hello", false},
    // Truncated UTF-8 sequence.
    {"\xe4\xa0\xe5\xa5\xbd", L"\x597d", false},
    // Truncated off the end.
    {"\xe5\xa5\xbd\xe4\xa0", L"\x597d", false},
    // Non-shortest-form UTF-8.
    {"\xf0\x84\xbd\xa0\xe5\xa5\xbd", L"\x597d", false},
    // This UTF-8 character decodes to a UTF-16 surrogate, which is illegal.
    {"\xed\xb0\x80", L"", false},
    // Non-BMP character. The result will either be in UTF-16 or UTF-32.
#if defined(WCHAR_T_IS_UTF16)
    {"A\xF0\x90\x8C\x80z", L"A\xd800\xdf00z", true},
#elif defined(WCHAR_T_IS_UTF32)
    {"A\xF0\x90\x8C\x80z", L"A\x10300z", true},
#endif
  };

  for (size_t i = 0; i < ARRAYSIZE_UNSAFE(convert_cases); i++) {
    std::wstring converted;
    EXPECT_EQ(convert_cases[i].success,
              UTF8ToWide(convert_cases[i].utf8,
                         strlen(convert_cases[i].utf8),
                         &converted));
    std::wstring expected(convert_cases[i].wide);
    EXPECT_EQ(expected, converted);
  }

  // Manually test an embedded NULL.
  std::wstring converted;
  EXPECT_TRUE(UTF8ToWide("\00Z\t", 3, &converted));
  ASSERT_EQ(3U, converted.length());
#if defined(WCHAR_T_IS_UNSIGNED)
  EXPECT_EQ(0U, converted[0]);
#else
  EXPECT_EQ(0, converted[0]);
#endif
  EXPECT_EQ('Z', converted[1]);
  EXPECT_EQ('\t', converted[2]);

  // Make sure that conversion replaces, not appends.
  EXPECT_TRUE(UTF8ToWide("B", 1, &converted));
  ASSERT_EQ(1U, converted.length());
  EXPECT_EQ('B', converted[0]);
}

#if defined(WCHAR_T_IS_UTF16)
// This test is only valid when wchar_t == UTF-16.
TEST(StringUtilTest, ConvertUTF16ToUTF8) {
  struct UTF16ToUTF8Case {
    const wchar_t* utf16;
    const char* utf8;
    bool success;
  } convert_cases[] = {
    // Regular UTF-16 input.
    {L"\x4f60\x597d", "\xe4\xbd\xa0\xe5\xa5\xbd", true},
    // Test a non-BMP character.
    {L"\xd800\xdf00", "\xF0\x90\x8C\x80", true},
    // Invalid Unicode code point.
    {L"\xffffHello", "Hello", false},
    // The first character is a truncated UTF-16 character.
    {L"\xd800\x597d", "\xe5\xa5\xbd", false},
    // Truncated at the end.
    {L"\x597d\xd800", "\xe5\xa5\xbd", false},
  };

  for (int i = 0; i < arraysize(convert_cases); i++) {
    std::string converted;
    EXPECT_EQ(convert_cases[i].success,
              WideToUTF8(convert_cases[i].utf16,
                         wcslen(convert_cases[i].utf16),
                         &converted));
    std::string expected(convert_cases[i].utf8);
    EXPECT_EQ(expected, converted);
  }
}

#elif defined(WCHAR_T_IS_UTF32)
// This test is only valid when wchar_t == UTF-32.
TEST(StringUtilTest, ConvertUTF32ToUTF8) {
  struct UTF8ToWideCase {
    const wchar_t* utf32;
    const char* utf8;
    bool success;
  } convert_cases[] = {
    // Regular 16-bit input.
    {L"\x4f60\x597d", "\xe4\xbd\xa0\xe5\xa5\xbd", true},
    // Test a non-BMP character.
    {L"A\x10300z", "A\xF0\x90\x8C\x80z", true},
    // Invalid Unicode code points.
    {L"\xffffHello", "Hello", false},
    {L"\xfffffffHello", "Hello", false},
    // The first character is a truncated UTF-16 character.
    {L"\xd800\x597d", "\xe5\xa5\xbd", false},
  };

  for (size_t i = 0; i < ARRAYSIZE_UNSAFE(convert_cases); i++) {
    std::string converted;
    EXPECT_EQ(convert_cases[i].success,
              WideToUTF8(convert_cases[i].utf32,
                         wcslen(convert_cases[i].utf32),
                         &converted));
    std::string expected(convert_cases[i].utf8);
    EXPECT_EQ(expected, converted);
  }
}
#endif  // defined(WCHAR_T_IS_UTF32)

TEST(StringUtilTest, ConvertMultiString) {
  static wchar_t wmulti[] = {
    L'f', L'o', L'o', L'\0',
    L'b', L'a', L'r', L'\0',
    L'b', L'a', L'z', L'\0',
    L'\0'
  };
  static char multi[] = {
    'f', 'o', 'o', '\0',
    'b', 'a', 'r', '\0',
    'b', 'a', 'z', '\0',
    '\0'
  };
  std::wstring wmultistring;
  memcpy(WriteInto(&wmultistring, arraysize(wmulti)), wmulti, sizeof(wmulti));
  EXPECT_EQ(arraysize(wmulti) - 1, wmultistring.length());
  std::string expected;
  memcpy(WriteInto(&expected, arraysize(multi)), multi, sizeof(multi));
  EXPECT_EQ(arraysize(multi) - 1, expected.length());
  const std::string& converted = WideToUTF8(wmultistring);
  EXPECT_EQ(arraysize(multi) - 1, converted.length());
  EXPECT_EQ(expected, converted);
}

TEST(StringUtilTest, ConvertCodepageUTF8) {
  // Make sure WideToCodepage works like WideToUTF8.
  for (size_t i = 0; i < arraysize(kConvertRoundtripCases); ++i) {
    std::string expected(WideToUTF8(kConvertRoundtripCases[i]));
    std::string utf8;
    EXPECT_TRUE(WideToCodepage(kConvertRoundtripCases[i], kCodepageUTF8,
                               OnStringUtilConversionError::SKIP, &utf8));
    EXPECT_EQ(expected, utf8);
  }
}

TEST(StringUtilTest, ConvertBetweenCodepageAndWide) {
  static const struct {
    const char* codepage_name;
    const char* encoded;
    OnStringUtilConversionError::Type on_error;
    bool success;
    const wchar_t* wide;
  } kConvertCodepageCases[] = {
    // Test a case where the input can no be decoded, using both SKIP and FAIL
    // error handling rules. "A7 41" is valid, but "A6" isn't.
    {"big5",
     "\xA7\x41\xA6",
     OnStringUtilConversionError::FAIL,
     false,
     L""},
    {"big5",
     "\xA7\x41\xA6",
     OnStringUtilConversionError::SKIP,
     true,
     L"\x4F60"},
    // Arabic (ISO-8859)
    {"iso-8859-6",
     "\xC7\xEE\xE4\xD3\xF1\xEE\xE4\xC7\xE5\xEF" " "
     "\xD9\xEE\xE4\xEE\xEA\xF2\xE3\xEF\xE5\xF2",
     OnStringUtilConversionError::FAIL,
     true,
     L"\x0627\x064E\x0644\x0633\x0651\x064E\x0644\x0627\x0645\x064F" L" "
     L"\x0639\x064E\x0644\x064E\x064A\x0652\x0643\x064F\x0645\x0652"},
    // Chinese Simplified (GB2312)
    {"gb2312",
     "\xC4\xE3\xBA\xC3",
     OnStringUtilConversionError::FAIL,
     true,
     L"\x4F60\x597D"},
    // Chinese Traditional (BIG5)
    {"big5",
     "\xA7\x41\xA6\x6E",
     OnStringUtilConversionError::FAIL,
     true,
     L"\x4F60\x597D"},
    // Greek (ISO-8859)
    {"iso-8859-7",
     "\xE3\xE5\xE9\xDC" " " "\xF3\xEF\xF5",
     OnStringUtilConversionError::FAIL,
     true,
     L"\x03B3\x03B5\x03B9\x03AC" L" " L"\x03C3\x03BF\x03C5"},
    // Hebrew (Windows)
    {"windows-1255", /* to be replaced with "iso-8859-8-I"? */
     "\xF9\xD1\xC8\xEC\xE5\xC9\xED",
     OnStringUtilConversionError::FAIL,
     true,
     L"\x05E9\x05C1\x05B8\x05DC\x05D5\x05B9\x05DD"},
    // Hindi Devanagari (ISCII)
    {"iscii-dev",
     "\xEF\x42" "\xC6\xCC\xD7\xE8\xB3\xDA\xCF",
     OnStringUtilConversionError::FAIL,
     true,
     L"\x0928\x092E\x0938\x094D\x0915\x093E\x0930"},
    // Korean (EUC)
    {"euc-kr",
     "\xBE\xC8\xB3\xE7\xC7\xCF\xBC\xBC\xBF\xE4",
     OnStringUtilConversionError::FAIL,
     true,
     L"\xC548\xB155\xD558\xC138\xC694"},
    // Japanese (EUC)
    {"euc-jp",
     "\xA4\xB3\xA4\xF3\xA4\xCB\xA4\xC1\xA4\xCF",
     OnStringUtilConversionError::FAIL,
     true,
     L"\x3053\x3093\x306B\x3061\x306F"},
    // Japanese (ISO-2022)
    {"iso-2022-jp",
     "\x1B\x24\x42" "\x24\x33\x24\x73\x24\x4B\x24\x41\x24\x4F" "\x1B\x28\x42",
     OnStringUtilConversionError::FAIL,
     true,
     L"\x3053\x3093\x306B\x3061\x306F"},
    // Japanese (Shift-JIS)
    {"sjis",
     "\x82\xB1\x82\xF1\x82\xC9\x82\xBF\x82\xCD",
     OnStringUtilConversionError::FAIL,
     true,
     L"\x3053\x3093\x306B\x3061\x306F"},
    // Russian (KOI8)
    {"koi8-r",
     "\xDA\xC4\xD2\xC1\xD7\xD3\xD4\xD7\xD5\xCA\xD4\xC5",
     OnStringUtilConversionError::FAIL,
     true,
     L"\x0437\x0434\x0440\x0430\x0432\x0441\x0442\x0432"
     L"\x0443\x0439\x0442\x0435"},
    // Thai (ISO-8859)
    {"windows-874", /* to be replaced with "iso-8859-11". */
     "\xCA\xC7\xD1\xCA\xB4\xD5" "\xA4\xC3\xD1\xBA",
     OnStringUtilConversionError::FAIL,
     true,
     L"\x0E2A\x0E27\x0E31\x0E2A\x0E14\x0E35"
     L"\x0E04\x0E23\x0e31\x0E1A"},
  };

  for (size_t i = 0; i < ARRAYSIZE_UNSAFE(kConvertCodepageCases); ++i) {
    std::wstring wide;
    bool success = CodepageToWide(kConvertCodepageCases[i].encoded,
                                  kConvertCodepageCases[i].codepage_name,
                                  kConvertCodepageCases[i].on_error,
                                  &wide);
    EXPECT_EQ(kConvertCodepageCases[i].success, success);
    EXPECT_EQ(kConvertCodepageCases[i].wide, wide);

    // When decoding was successful and nothing was skipped, we also check the
    // reverse conversion.
    if (success &&
        kConvertCodepageCases[i].on_error ==
            OnStringUtilConversionError::FAIL) {
      std::string encoded;
      success = WideToCodepage(wide, kConvertCodepageCases[i].codepage_name,
                               kConvertCodepageCases[i].on_error, &encoded);
      EXPECT_EQ(kConvertCodepageCases[i].success, success);
      EXPECT_EQ(kConvertCodepageCases[i].encoded, encoded);
    }
  }

  // The above cases handled codepage->wide errors, but not wide->codepage.
  // Test that here.
  std::string encoded("Temp data");  // Make sure the string gets cleared.

  // First test going to an encoding that can not represent that character.
  EXPECT_FALSE(WideToCodepage(L"Chinese\xff27", "iso-8859-1",
                              OnStringUtilConversionError::FAIL, &encoded));
  EXPECT_TRUE(encoded.empty());
  EXPECT_TRUE(WideToCodepage(L"Chinese\xff27", "iso-8859-1",
                             OnStringUtilConversionError::SKIP, &encoded));
  EXPECT_STREQ("Chinese", encoded.c_str());

#if defined(WCHAR_T_IS_UTF16)
  // When we're in UTF-16 mode, test an invalid UTF-16 character in the input.
  EXPECT_FALSE(WideToCodepage(L"a\xd800z", "iso-8859-1",
                              OnStringUtilConversionError::FAIL, &encoded));
  EXPECT_TRUE(encoded.empty());
  EXPECT_TRUE(WideToCodepage(L"a\xd800z", "iso-8859-1",
                             OnStringUtilConversionError::SKIP, &encoded));
  EXPECT_STREQ("az", encoded.c_str());
#endif  // WCHAR_T_IS_UTF16

  // Invalid characters should fail.
  EXPECT_TRUE(WideToCodepage(L"a\xffffz", "iso-8859-1",
                             OnStringUtilConversionError::SKIP, &encoded));
  EXPECT_STREQ("az", encoded.c_str());

  // Invalid codepages should fail.
  EXPECT_FALSE(WideToCodepage(L"Hello, world", "awesome-8571-2",
                              OnStringUtilConversionError::SKIP, &encoded));
}

TEST(StringUtilTest, ConvertASCII) {
  static const char* char_cases[] = {
    "Google Video",
    "Hello, world\n",
    "0123ABCDwxyz \a\b\t\r\n!+,.~"
  };

  static const wchar_t* const wchar_cases[] = {
    L"Google Video",
    L"Hello, world\n",
    L"0123ABCDwxyz \a\b\t\r\n!+,.~"
  };

  for (size_t i = 0; i < arraysize(char_cases); ++i) {
    EXPECT_TRUE(IsStringASCII(char_cases[i]));
    std::wstring wide = ASCIIToWide(char_cases[i]);
    EXPECT_EQ(wchar_cases[i], wide);

    EXPECT_TRUE(IsStringASCII(wchar_cases[i]));
    std::string ascii = WideToASCII(wchar_cases[i]);
    EXPECT_EQ(char_cases[i], ascii);
  }

  EXPECT_FALSE(IsStringASCII("Google \x80Video"));
  EXPECT_FALSE(IsStringASCII(L"Google \x80Video"));

  // Convert empty strings.
  std::wstring wempty;
  std::string empty;
  EXPECT_EQ(empty, WideToASCII(wempty));
  EXPECT_EQ(wempty, ASCIIToWide(empty));

  // Convert strings with an embedded NUL character.
  const char chars_with_nul[] = "test\0string";
  const int length_with_nul = arraysize(chars_with_nul) - 1;
  std::string string_with_nul(chars_with_nul, length_with_nul);
  std::wstring wide_with_nul = ASCIIToWide(string_with_nul);
  EXPECT_EQ(static_cast<std::wstring::size_type>(length_with_nul),
            wide_with_nul.length());
  std::string narrow_with_nul = WideToASCII(wide_with_nul);
  EXPECT_EQ(static_cast<std::string::size_type>(length_with_nul),
            narrow_with_nul.length());
  EXPECT_EQ(0, string_with_nul.compare(narrow_with_nul));
}

TEST(StringUtilTest, ToUpperASCII) {
  EXPECT_EQ('C', ToUpperASCII('C'));
  EXPECT_EQ('C', ToUpperASCII('c'));
  EXPECT_EQ('2', ToUpperASCII('2'));

  EXPECT_EQ(L'C', ToUpperASCII(L'C'));
  EXPECT_EQ(L'C', ToUpperASCII(L'c'));
  EXPECT_EQ(L'2', ToUpperASCII(L'2'));

  std::string in_place_a("Cc2");
  StringToUpperASCII(&in_place_a);
  EXPECT_EQ("CC2", in_place_a);

  std::wstring in_place_w(L"Cc2");
  StringToUpperASCII(&in_place_w);
  EXPECT_EQ(L"CC2", in_place_w);

  std::string original_a("Cc2");
  std::string upper_a = StringToUpperASCII(original_a);
  EXPECT_EQ("CC2", upper_a);

  std::wstring original_w(L"Cc2");
  std::wstring upper_w = StringToUpperASCII(original_w);
  EXPECT_EQ(L"CC2", upper_w);
}

static const struct {
  const wchar_t* src_w;
  const char*    src_a;
  const char*    dst;
} lowercase_cases[] = {
  {L"FoO", "FoO", "foo"},
  {L"foo", "foo", "foo"},
  {L"FOO", "FOO", "foo"},
};

TEST(StringUtilTest, LowerCaseEqualsASCII) {
  for (size_t i = 0; i < ARRAYSIZE_UNSAFE(lowercase_cases); ++i) {
    EXPECT_TRUE(LowerCaseEqualsASCII(lowercase_cases[i].src_w,
                                     lowercase_cases[i].dst));
    EXPECT_TRUE(LowerCaseEqualsASCII(lowercase_cases[i].src_a,
                                     lowercase_cases[i].dst));
  }
}

TEST(StringUtilTest, GetByteDisplayUnits) {
  static const struct {
    int64 bytes;
    DataUnits expected;
  } cases[] = {
    {0, DATA_UNITS_BYTE},
    {512, DATA_UNITS_BYTE},
    {10*1024, DATA_UNITS_KILOBYTE},
    {10*1024*1024, DATA_UNITS_MEGABYTE},
    {10LL*1024*1024*1024, DATA_UNITS_GIGABYTE},
    {~(1LL<<63), DATA_UNITS_GIGABYTE},
#ifdef NDEBUG
    {-1, DATA_UNITS_BYTE},
#endif
  };

  for (size_t i = 0; i < ARRAYSIZE_UNSAFE(cases); ++i)
    EXPECT_EQ(cases[i].expected, GetByteDisplayUnits(cases[i].bytes));
}

TEST(StringUtilTest, FormatBytes) {
  static const struct {
    int64 bytes;
    DataUnits units;
    const wchar_t* expected;
    const wchar_t* expected_with_units;
  } cases[] = {
    {0, DATA_UNITS_BYTE, L"0", L"0 B"},
    {512, DATA_UNITS_BYTE, L"512", L"512 B"},
    {512, DATA_UNITS_KILOBYTE, L"0.5", L"0.5 kB"},
    {1024*1024, DATA_UNITS_KILOBYTE, L"1024", L"1024 kB"},
    {1024*1024, DATA_UNITS_MEGABYTE, L"1", L"1 MB"},
    {1024*1024*1024, DATA_UNITS_GIGABYTE, L"1", L"1 GB"},
    {10LL*1024*1024*1024, DATA_UNITS_GIGABYTE, L"10", L"10 GB"},
    {~(1LL<<63), DATA_UNITS_GIGABYTE, L"8589934592", L"8589934592 GB"},
    // Make sure the first digit of the fractional part works.
    {1024*1024 + 103, DATA_UNITS_KILOBYTE, L"1024.1", L"1024.1 kB"},
    {1024*1024 + 205 * 1024, DATA_UNITS_MEGABYTE, L"1.2", L"1.2 MB"},
    {1024*1024*1024 + (927 * 1024*1024), DATA_UNITS_GIGABYTE,
     L"1.9", L"1.9 GB"},
    {10LL*1024*1024*1024, DATA_UNITS_GIGABYTE, L"10", L"10 GB"},
#ifdef NDEBUG
    {-1, DATA_UNITS_BYTE, L"", L""},
#endif
  };

  for (size_t i = 0; i < ARRAYSIZE_UNSAFE(cases); ++i) {
    EXPECT_EQ(cases[i].expected,
              FormatBytes(cases[i].bytes, cases[i].units, false));
    EXPECT_EQ(cases[i].expected_with_units,
              FormatBytes(cases[i].bytes, cases[i].units, true));
  }
}

TEST(StringUtilTest, ReplaceSubstringsAfterOffset) {
  static const struct {
    const char* str;
    string16::size_type start_offset;
    const char* find_this;
    const char* replace_with;
    const char* expected;
  } cases[] = {
    {"aaa", 0, "a", "b", "bbb"},
    {"abb", 0, "ab", "a", "ab"},
    {"Removing some substrings inging", 0, "ing", "", "Remov some substrs "},
    {"Not found", 0, "x", "0", "Not found"},
    {"Not found again", 5, "x", "0", "Not found again"},
    {" Making it much longer ", 0, " ", "Four score and seven years ago",
     "Four score and seven years agoMakingFour score and seven years agoit"
     "Four score and seven years agomuchFour score and seven years agolonger"
     "Four score and seven years ago"},
    {"Invalid offset", 9999, "t", "foobar", "Invalid offset"},
    {"Replace me only me once", 9, "me ", "", "Replace me only once"},
    {"abababab", 2, "ab", "c", "abccc"},
  };

  for (size_t i = 0; i < ARRAYSIZE_UNSAFE(cases); i++) {
    string16 str = ASCIIToUTF16(cases[i].str);
    ReplaceSubstringsAfterOffset(&str, cases[i].start_offset,
                                 ASCIIToUTF16(cases[i].find_this),
                                 ASCIIToUTF16(cases[i].replace_with));
    EXPECT_EQ(ASCIIToUTF16(cases[i].expected), str);
  }
}

TEST(StringUtilTest, ReplaceFirstSubstringAfterOffset) {
  static const struct {
    const char* str;
    string16::size_type start_offset;
    const char* find_this;
    const char* replace_with;
    const char* expected;
  } cases[] = {
    {"aaa", 0, "a", "b", "baa"},
    {"abb", 0, "ab", "a", "ab"},
    {"Removing some substrings inging", 0, "ing", "",
      "Remov some substrings inging"},
    {"Not found", 0, "x", "0", "Not found"},
    {"Not found again", 5, "x", "0", "Not found again"},
    {" Making it much longer ", 0, " ", "Four score and seven years ago",
     "Four score and seven years agoMaking it much longer "},
    {"Invalid offset", 9999, "t", "foobar", "Invalid offset"},
    {"Replace me only me once", 4, "me ", "", "Replace only me once"},
    {"abababab", 2, "ab", "c", "abcabab"},
  };

  for (size_t i = 0; i < ARRAYSIZE_UNSAFE(cases); i++) {
    string16 str = ASCIIToUTF16(cases[i].str);
    ReplaceFirstSubstringAfterOffset(&str, cases[i].start_offset,
                                     ASCIIToUTF16(cases[i].find_this),
                                     ASCIIToUTF16(cases[i].replace_with));
    EXPECT_EQ(ASCIIToUTF16(cases[i].expected), str);
  }
}

namespace {

template <typename INT>
struct IntToStringTest {
  INT num;
  const char* sexpected;
  const char* uexpected;
};

}

TEST(StringUtilTest, IntToString) {

  static const IntToStringTest<int> int_tests[] = {
      { 0, "0", "0" },
      { -1, "-1", "4294967295" },
      { std::numeric_limits<int>::max(), "2147483647", "2147483647" },
      { std::numeric_limits<int>::min(), "-2147483648", "2147483648" },
  };
  static const IntToStringTest<int64> int64_tests[] = {
      { 0, "0", "0" },
      { -1, "-1", "18446744073709551615" },
      { std::numeric_limits<int64>::max(),
        "9223372036854775807",
        "9223372036854775807", },
      { std::numeric_limits<int64>::min(),
        "-9223372036854775808",
        "9223372036854775808" },
  };

  for (size_t i = 0; i < arraysize(int_tests); ++i) {
    const IntToStringTest<int>* test = &int_tests[i];
    EXPECT_EQ(IntToString(test->num), test->sexpected);
    EXPECT_EQ(IntToWString(test->num), UTF8ToWide(test->sexpected));
    EXPECT_EQ(UintToString(test->num), test->uexpected);
    EXPECT_EQ(UintToWString(test->num), UTF8ToWide(test->uexpected));
  }
  for (size_t i = 0; i < arraysize(int64_tests); ++i) {
    const IntToStringTest<int64>* test = &int64_tests[i];
    EXPECT_EQ(Int64ToString(test->num), test->sexpected);
    EXPECT_EQ(Int64ToWString(test->num), UTF8ToWide(test->sexpected));
    EXPECT_EQ(Uint64ToString(test->num), test->uexpected);
    EXPECT_EQ(Uint64ToWString(test->num), UTF8ToWide(test->uexpected));
  }
}

TEST(StringUtilTest, Uint64ToString) {
  static const struct {
    uint64 input;
    std::string output;
  } cases[] = {
    {0, "0"},
    {42, "42"},
    {INT_MAX, "2147483647"},
    {kuint64max, "18446744073709551615"},
  };

  for (size_t i = 0; i < ARRAYSIZE_UNSAFE(cases); ++i)
    EXPECT_EQ(cases[i].output, Uint64ToString(cases[i].input));
}

TEST(StringUtilTest, StringToInt) {
  static const struct {
    std::string input;
    int output;
    bool success;
  } cases[] = {
    {"0", 0, true},
    {"42", 42, true},
    {"-2147483648", INT_MIN, true},
    {"2147483647", INT_MAX, true},
    {"", 0, false},
    {" 42", 42, false},
    {"42 ", 42, false},
    {"\t\n\v\f\r 42", 42, false},
    {"blah42", 0, false},
    {"42blah", 42, false},
    {"blah42blah", 0, false},
    {"-273.15", -273, false},
    {"+98.6", 98, false},
    {"--123", 0, false},
    {"++123", 0, false},
    {"-+123", 0, false},
    {"+-123", 0, false},
    {"-", 0, false},
    {"-2147483649", INT_MIN, false},
    {"-99999999999", INT_MIN, false},
    {"2147483648", INT_MAX, false},
    {"99999999999", INT_MAX, false},
  };

  for (size_t i = 0; i < ARRAYSIZE_UNSAFE(cases); ++i) {
    EXPECT_EQ(cases[i].output, StringToInt(cases[i].input));
    int output;
    EXPECT_EQ(cases[i].success, StringToInt(cases[i].input, &output));
    EXPECT_EQ(cases[i].output, output);

    std::wstring wide_input = ASCIIToWide(cases[i].input);
    EXPECT_EQ(cases[i].output, StringToInt(WideToUTF16Hack(wide_input)));
    EXPECT_EQ(cases[i].success, StringToInt(WideToUTF16Hack(wide_input),
                                            &output));
    EXPECT_EQ(cases[i].output, output);
  }

  // One additional test to verify that conversion of numbers in strings with
  // embedded NUL characters.  The NUL and extra data after it should be
  // interpreted as junk after the number.
  const char input[] = "6\06";
  std::string input_string(input, arraysize(input) - 1);
  int output;
  EXPECT_FALSE(StringToInt(input_string, &output));
  EXPECT_EQ(6, output);

  std::wstring wide_input = ASCIIToWide(input_string);
  EXPECT_FALSE(StringToInt(WideToUTF16Hack(wide_input), &output));
  EXPECT_EQ(6, output);
}

TEST(StringUtilTest, StringToInt64) {
  static const struct {
    std::string input;
    int64 output;
    bool success;
  } cases[] = {
    {"0", 0, true},
    {"42", 42, true},
    {"-2147483648", INT_MIN, true},
    {"2147483647", INT_MAX, true},
    {"-2147483649", GG_INT64_C(-2147483649), true},
    {"-99999999999", GG_INT64_C(-99999999999), true},
    {"2147483648", GG_INT64_C(2147483648), true},
    {"99999999999", GG_INT64_C(99999999999), true},
    {"9223372036854775807", kint64max, true},
    {"-9223372036854775808", kint64min, true},
    {"09", 9, true},
    {"-09", -9, true},
    {"", 0, false},
    {" 42", 42, false},
    {"42 ", 42, false},
    {"\t\n\v\f\r 42", 42, false},
    {"blah42", 0, false},
    {"42blah", 42, false},
    {"blah42blah", 0, false},
    {"-273.15", -273, false},
    {"+98.6", 98, false},
    {"--123", 0, false},
    {"++123", 0, false},
    {"-+123", 0, false},
    {"+-123", 0, false},
    {"-", 0, false},
    {"-9223372036854775809", kint64min, false},
    {"-99999999999999999999", kint64min, false},
    {"9223372036854775808", kint64max, false},
    {"99999999999999999999", kint64max, false},
  };

  for (size_t i = 0; i < ARRAYSIZE_UNSAFE(cases); ++i) {
    EXPECT_EQ(cases[i].output, StringToInt64(cases[i].input));
    int64 output;
    EXPECT_EQ(cases[i].success, StringToInt64(cases[i].input, &output));
    EXPECT_EQ(cases[i].output, output);

    std::wstring wide_input = ASCIIToWide(cases[i].input);
    EXPECT_EQ(cases[i].output, StringToInt64(WideToUTF16Hack(wide_input)));
    EXPECT_EQ(cases[i].success, StringToInt64(WideToUTF16Hack(wide_input),
                                              &output));
    EXPECT_EQ(cases[i].output, output);
  }

  // One additional test to verify that conversion of numbers in strings with
  // embedded NUL characters.  The NUL and extra data after it should be
  // interpreted as junk after the number.
  const char input[] = "6\06";
  std::string input_string(input, arraysize(input) - 1);
  int64 output;
  EXPECT_FALSE(StringToInt64(input_string, &output));
  EXPECT_EQ(6, output);

  std::wstring wide_input = ASCIIToWide(input_string);
  EXPECT_FALSE(StringToInt64(WideToUTF16Hack(wide_input), &output));
  EXPECT_EQ(6, output);
}

TEST(StringUtilTest, HexStringToInt) {
  static const struct {
    std::string input;
    int output;
    bool success;
  } cases[] = {
    {"0", 0, true},
    {"42", 66, true},
    {"-42", -66, true},
    {"+42", 66, true},
    {"7fffffff", INT_MAX, true},
    {"80000000", INT_MIN, true},
    {"ffffffff", -1, true},
    {"DeadBeef", 0xdeadbeef, true},
    {"0x42", 66, true},
    {"-0x42", -66, true},
    {"+0x42", 66, true},
    {"0x7fffffff", INT_MAX, true},
    {"0x80000000", INT_MIN, true},
    {"0xffffffff", -1, true},
    {"0XDeadBeef", 0xdeadbeef, true},
    {"0x0f", 15, true},
    {"0f", 15, true},
    {" 45", 0x45, false},
    {"\t\n\v\f\r 0x45", 0x45, false},
    {" 45", 0x45, false},
    {"45 ", 0x45, false},
    {"efgh", 0xef, false},
    {"0xefgh", 0xef, false},
    {"hgfe", 0, false},
    {"100000000", -1, false},  // don't care about |output|, just |success|
    {"-", 0, false},
    {"", 0, false},
  };

  for (size_t i = 0; i < ARRAYSIZE_UNSAFE(cases); ++i) {
    EXPECT_EQ(cases[i].output, HexStringToInt(cases[i].input));
    int output;
    EXPECT_EQ(cases[i].success, HexStringToInt(cases[i].input, &output));
    EXPECT_EQ(cases[i].output, output);

    std::wstring wide_input = ASCIIToWide(cases[i].input);
    EXPECT_EQ(cases[i].output, HexStringToInt(WideToUTF16Hack(wide_input)));
    EXPECT_EQ(cases[i].success, HexStringToInt(WideToUTF16Hack(wide_input),
                                               &output));
    EXPECT_EQ(cases[i].output, output);
  }
  // One additional test to verify that conversion of numbers in strings with
  // embedded NUL characters.  The NUL and extra data after it should be
  // interpreted as junk after the number.
  const char input[] = "0xc0ffee\09";
  std::string input_string(input, arraysize(input) - 1);
  int output;
  EXPECT_FALSE(HexStringToInt(input_string, &output));
  EXPECT_EQ(0xc0ffee, output);

  std::wstring wide_input = ASCIIToWide(input_string);
  EXPECT_FALSE(HexStringToInt(WideToUTF16Hack(wide_input), &output));
  EXPECT_EQ(0xc0ffee, output);
}

TEST(StringUtilTest, HexStringToBytes) {
  static const struct {
    const std::string input;
    const char* output;
    size_t output_len;
    bool success;
  } cases[] = {
    {"0", "", 0, false},  // odd number of characters fails
    {"00", "\0", 1, true},
    {"42", "\x42", 1, true},
    {"-42", "", 0, false},  // any non-hex value fails
    {"+42", "", 0, false},
    {"7fffffff", "\x7f\xff\xff\xff", 4, true},
    {"80000000", "\x80\0\0\0", 4, true},
    {"deadbeef", "\xde\xad\xbe\xef", 4, true},
    {"DeadBeef", "\xde\xad\xbe\xef", 4, true},
    {"0x42", "", 0, false},  // leading 0x fails (x is not hex)
    {"0f", "\xf", 1, true},
    {"45  ", "\x45", 1, false},
    {"efgh", "\xef", 1, false},
    {"", "", 0, false},
    {"0123456789ABCDEF", "\x01\x23\x45\x67\x89\xAB\xCD\xEF", 8, true},
    {"0123456789ABCDEF012345",
     "\x01\x23\x45\x67\x89\xAB\xCD\xEF\x01\x23\x45", 11, true},
  };


  for (size_t i = 0; i < ARRAYSIZE_UNSAFE(cases); ++i) {
    std::vector<uint8> output;
    std::vector<uint8> compare;
    EXPECT_EQ(cases[i].success, HexStringToBytes(cases[i].input, &output)) <<
        i << ": " << cases[i].input;
    for (size_t j = 0; j < cases[i].output_len; ++j)
      compare.push_back(static_cast<uint8>(cases[i].output[j]));
    ASSERT_EQ(output.size(), compare.size()) << i << ": " << cases[i].input;
    EXPECT_TRUE(std::equal(output.begin(), output.end(), compare.begin())) <<
        i << ": " << cases[i].input;

    output.clear();
    compare.clear();

    std::wstring wide_input = ASCIIToWide(cases[i].input);
    EXPECT_EQ(cases[i].success,
              HexStringToBytes(WideToUTF16Hack(wide_input), &output)) <<
        i << ": " << cases[i].input;
    for (size_t j = 0; j < cases[i].output_len; ++j)
      compare.push_back(static_cast<uint8>(cases[i].output[j]));
    ASSERT_EQ(output.size(), compare.size()) << i << ": " << cases[i].input;
    EXPECT_TRUE(std::equal(output.begin(), output.end(), compare.begin())) <<
        i << ": " << cases[i].input;
  }
}

TEST(StringUtilTest, StringToDouble) {
  static const struct {
    std::string input;
    double output;
    bool success;
  } cases[] = {
    {"0", 0.0, true},
    {"42", 42.0, true},
    {"-42", -42.0, true},
    {"123.45", 123.45, true},
    {"-123.45", -123.45, true},
    {"+123.45", 123.45, true},
    {"2.99792458e8", 299792458.0, true},
    {"149597870.691E+3", 149597870691.0, true},
    {"6.", 6.0, true},
    {"9e99999999999999999999", HUGE_VAL, false},
    {"-9e99999999999999999999", -HUGE_VAL, false},
    {"1e-2", 0.01, true},
    {" 1e-2", 0.01, false},
    {"1e-2 ", 0.01, false},
    {"-1E-7", -0.0000001, true},
    {"01e02", 100, true},
    {"2.3e15", 2.3e15, true},
    {"\t\n\v\f\r -123.45e2", -12345.0, false},
    {"+123 e4", 123.0, false},
    {"123e ", 123.0, false},
    {"123e", 123.0, false},
    {" 2.99", 2.99, false},
    {"1e3.4", 1000.0, false},
    {"nothing", 0.0, false},
    {"-", 0.0, false},
    {"+", 0.0, false},
    {"", 0.0, false},
  };

  for (size_t i = 0; i < ARRAYSIZE_UNSAFE(cases); ++i) {
    EXPECT_DOUBLE_EQ(cases[i].output, StringToDouble(cases[i].input));
    double output;
    EXPECT_EQ(cases[i].success, StringToDouble(cases[i].input, &output));
    EXPECT_DOUBLE_EQ(cases[i].output, output);

    std::wstring wide_input = ASCIIToWide(cases[i].input);
    EXPECT_DOUBLE_EQ(cases[i].output,
                     StringToDouble(WideToUTF16Hack(wide_input)));
    EXPECT_EQ(cases[i].success, StringToDouble(WideToUTF16Hack(wide_input),
                                               &output));
    EXPECT_DOUBLE_EQ(cases[i].output, output);
  }

  // One additional test to verify that conversion of numbers in strings with
  // embedded NUL characters.  The NUL and extra data after it should be
  // interpreted as junk after the number.
  const char input[] = "3.14\0159";
  std::string input_string(input, arraysize(input) - 1);
  double output;
  EXPECT_FALSE(StringToDouble(input_string, &output));
  EXPECT_DOUBLE_EQ(3.14, output);

  std::wstring wide_input = ASCIIToWide(input_string);
  EXPECT_FALSE(StringToDouble(WideToUTF16Hack(wide_input), &output));
  EXPECT_DOUBLE_EQ(3.14, output);
}

// This checks where we can use the assignment operator for a va_list. We need
// a way to do this since Visual C doesn't support va_copy, but assignment on
// va_list is not guaranteed to be a copy. See StringAppendVT which uses this
// capability.
static void VariableArgsFunc(const char* format, ...) {
  va_list org;
  va_start(org, format);

  va_list dup;
  base::va_copy(dup, org);
  int i1 = va_arg(org, int);
  int j1 = va_arg(org, int);
  char* s1 = va_arg(org, char*);
  double d1 = va_arg(org, double);
  va_end(org);

  int i2 = va_arg(dup, int);
  int j2 = va_arg(dup, int);
  char* s2 = va_arg(dup, char*);
  double d2 = va_arg(dup, double);

  EXPECT_EQ(i1, i2);
  EXPECT_EQ(j1, j2);
  EXPECT_STREQ(s1, s2);
  EXPECT_EQ(d1, d2);

  va_end(dup);
}

TEST(StringUtilTest, VAList) {
  VariableArgsFunc("%d %d %s %lf", 45, 92, "This is interesting", 9.21);
}

TEST(StringUtilTest, StringPrintfEmptyFormat) {
  const char* empty = "";
  EXPECT_EQ("", StringPrintf(empty));
  EXPECT_EQ("", StringPrintf("%s", ""));
}

TEST(StringUtilTest, StringPrintfMisc) {
  EXPECT_EQ("123hello w", StringPrintf("%3d%2s %1c", 123, "hello", 'w'));
  EXPECT_EQ(L"123hello w", StringPrintf(L"%3d%2ls %1lc", 123, L"hello", 'w'));
}

TEST(StringUtilTest, StringAppendfStringEmptyParam) {
  std::string value("Hello");
  StringAppendF(&value, "");
  EXPECT_EQ("Hello", value);

  std::wstring valuew(L"Hello");
  StringAppendF(&valuew, L"");
  EXPECT_EQ(L"Hello", valuew);
}

TEST(StringUtilTest, StringAppendfEmptyString) {
  std::string value("Hello");
  StringAppendF(&value, "%s", "");
  EXPECT_EQ("Hello", value);

  std::wstring valuew(L"Hello");
  StringAppendF(&valuew, L"%ls", L"");
  EXPECT_EQ(L"Hello", valuew);
}

TEST(StringUtilTest, StringAppendfString) {
  std::string value("Hello");
  StringAppendF(&value, " %s", "World");
  EXPECT_EQ("Hello World", value);

  std::wstring valuew(L"Hello");
  StringAppendF(&valuew, L" %ls", L"World");
  EXPECT_EQ(L"Hello World", valuew);
}

TEST(StringUtilTest, StringAppendfInt) {
  std::string value("Hello");
  StringAppendF(&value, " %d", 123);
  EXPECT_EQ("Hello 123", value);

  std::wstring valuew(L"Hello");
  StringAppendF(&valuew, L" %d", 123);
  EXPECT_EQ(L"Hello 123", valuew);
}

// Make sure that lengths exactly around the initial buffer size are handled
// correctly.
TEST(StringUtilTest, StringPrintfBounds) {
  const int src_len = 1026;
  char src[src_len];
  for (size_t i = 0; i < arraysize(src); i++)
    src[i] = 'A';

  wchar_t srcw[src_len];
  for (size_t i = 0; i < arraysize(srcw); i++)
    srcw[i] = 'A';

  for (int i = 1; i < 3; i++) {
    src[src_len - i] = 0;
    std::string out;
    SStringPrintf(&out, "%s", src);
    EXPECT_STREQ(src, out.c_str());

    srcw[src_len - i] = 0;
    std::wstring outw;
    SStringPrintf(&outw, L"%ls", srcw);
    EXPECT_STREQ(srcw, outw.c_str());
  }
}

// Test very large sprintfs that will cause the buffer to grow.
TEST(StringUtilTest, Grow) {
  char src[1026];
  for (size_t i = 0; i < arraysize(src); i++)
    src[i] = 'A';
  src[1025] = 0;

  const char* fmt = "%sB%sB%sB%sB%sB%sB%s";

  std::string out;
  SStringPrintf(&out, fmt, src, src, src, src, src, src, src);

  char* ref = new char[320000];
#if defined(OS_WIN)
  sprintf_s(ref, 320000, fmt, src, src, src, src, src, src, src);
#elif defined(OS_POSIX)
  snprintf(ref, 320000, fmt, src, src, src, src, src, src, src);
#endif

  EXPECT_STREQ(ref, out.c_str());
  delete[] ref;
}

// Test the boundary condition for the size of the string_util's
// internal buffer.
TEST(StringUtilTest, GrowBoundary) {
  const int string_util_buf_len = 1024;
  // Our buffer should be one larger than the size of StringAppendVT's stack
  // buffer.
  const int buf_len = string_util_buf_len + 1;
  char src[buf_len + 1];  // Need extra one for NULL-terminator.
  for (int i = 0; i < buf_len; ++i)
    src[i] = 'a';
  src[buf_len] = 0;

  std::string out;
  SStringPrintf(&out, "%s", src);

  EXPECT_STREQ(src, out.c_str());
}

// TODO(evanm): what's the proper cross-platform test here?
#if defined(OS_WIN)
// sprintf in Visual Studio fails when given U+FFFF. This tests that the
// failure case is gracefuly handled.
TEST(StringUtilTest, Invalid) {
  wchar_t invalid[2];
  invalid[0] = 0xffff;
  invalid[1] = 0;

  std::wstring out;
  SStringPrintf(&out, L"%ls", invalid);
  EXPECT_STREQ(L"", out.c_str());
}
#endif

// Test for SplitString
TEST(StringUtilTest, SplitString) {
  std::vector<std::wstring> r;

  SplitString(L"a,b,c", L',', &r);
  EXPECT_EQ(3U, r.size());
  EXPECT_EQ(r[0], L"a");
  EXPECT_EQ(r[1], L"b");
  EXPECT_EQ(r[2], L"c");
  r.clear();

  SplitString(L"a, b, c", L',', &r);
  EXPECT_EQ(3U, r.size());
  EXPECT_EQ(r[0], L"a");
  EXPECT_EQ(r[1], L"b");
  EXPECT_EQ(r[2], L"c");
  r.clear();

  SplitString(L"a,,c", L',', &r);
  EXPECT_EQ(3U, r.size());
  EXPECT_EQ(r[0], L"a");
  EXPECT_EQ(r[1], L"");
  EXPECT_EQ(r[2], L"c");
  r.clear();

  SplitString(L"", L'*', &r);
  EXPECT_EQ(1U, r.size());
  EXPECT_EQ(r[0], L"");
  r.clear();

  SplitString(L"foo", L'*', &r);
  EXPECT_EQ(1U, r.size());
  EXPECT_EQ(r[0], L"foo");
  r.clear();

  SplitString(L"foo ,", L',', &r);
  EXPECT_EQ(2U, r.size());
  EXPECT_EQ(r[0], L"foo");
  EXPECT_EQ(r[1], L"");
  r.clear();

  SplitString(L",", L',', &r);
  EXPECT_EQ(2U, r.size());
  EXPECT_EQ(r[0], L"");
  EXPECT_EQ(r[1], L"");
  r.clear();

  SplitString(L"\t\ta\t", L'\t', &r);
  EXPECT_EQ(4U, r.size());
  EXPECT_EQ(r[0], L"");
  EXPECT_EQ(r[1], L"");
  EXPECT_EQ(r[2], L"a");
  EXPECT_EQ(r[3], L"");
  r.clear();

  SplitStringDontTrim(L"\t\ta\t", L'\t', &r);
  EXPECT_EQ(4U, r.size());
  EXPECT_EQ(r[0], L"");
  EXPECT_EQ(r[1], L"");
  EXPECT_EQ(r[2], L"a");
  EXPECT_EQ(r[3], L"");
  r.clear();

  SplitString(L"\ta\t\nb\tcc", L'\n', &r);
  EXPECT_EQ(2U, r.size());
  EXPECT_EQ(r[0], L"a");
  EXPECT_EQ(r[1], L"b\tcc");
  r.clear();

  SplitStringDontTrim(L"\ta\t\nb\tcc", L'\n', &r);
  EXPECT_EQ(2U, r.size());
  EXPECT_EQ(r[0], L"\ta\t");
  EXPECT_EQ(r[1], L"b\tcc");
  r.clear();
}

// Test for JoinString
TEST(StringUtilTest, JoinString) {
  std::vector<std::string> in;
  EXPECT_EQ("", JoinString(in, ','));

  in.push_back("a");
  EXPECT_EQ("a", JoinString(in, ','));

  in.push_back("b");
  in.push_back("c");
  EXPECT_EQ("a,b,c", JoinString(in, ','));

  in.push_back("");
  EXPECT_EQ("a,b,c,", JoinString(in, ','));
  in.push_back(" ");
  EXPECT_EQ("a|b|c|| ", JoinString(in, '|'));
}

TEST(StringUtilTest, StartsWith) {
  EXPECT_TRUE(StartsWithASCII("javascript:url", "javascript", true));
  EXPECT_FALSE(StartsWithASCII("JavaScript:url", "javascript", true));
  EXPECT_TRUE(StartsWithASCII("javascript:url", "javascript", false));
  EXPECT_TRUE(StartsWithASCII("JavaScript:url", "javascript", false));
  EXPECT_FALSE(StartsWithASCII("java", "javascript", true));
  EXPECT_FALSE(StartsWithASCII("java", "javascript", false));
  EXPECT_FALSE(StartsWithASCII("", "javascript", false));
  EXPECT_FALSE(StartsWithASCII("", "javascript", true));
  EXPECT_TRUE(StartsWithASCII("java", "", false));
  EXPECT_TRUE(StartsWithASCII("java", "", true));

  EXPECT_TRUE(StartsWith(L"javascript:url", L"javascript", true));
  EXPECT_FALSE(StartsWith(L"JavaScript:url", L"javascript", true));
  EXPECT_TRUE(StartsWith(L"javascript:url", L"javascript", false));
  EXPECT_TRUE(StartsWith(L"JavaScript:url", L"javascript", false));
  EXPECT_FALSE(StartsWith(L"java", L"javascript", true));
  EXPECT_FALSE(StartsWith(L"java", L"javascript", false));
  EXPECT_FALSE(StartsWith(L"", L"javascript", false));
  EXPECT_FALSE(StartsWith(L"", L"javascript", true));
  EXPECT_TRUE(StartsWith(L"java", L"", false));
  EXPECT_TRUE(StartsWith(L"java", L"", true));
}

TEST(StringUtilTest, GetStringFWithOffsets) {
  std::vector<string16> subst;
  subst.push_back(ASCIIToUTF16("1"));
  subst.push_back(ASCIIToUTF16("2"));
  std::vector<size_t> offsets;

  ReplaceStringPlaceholders(ASCIIToUTF16("Hello, $1. Your number is $2."),
                            subst,
                            &offsets);
  EXPECT_EQ(2U, offsets.size());
  EXPECT_EQ(7U, offsets[0]);
  EXPECT_EQ(25U, offsets[1]);
  offsets.clear();

  ReplaceStringPlaceholders(ASCIIToUTF16("Hello, $2. Your number is $1."),
                            subst,
                            &offsets);
  EXPECT_EQ(2U, offsets.size());
  EXPECT_EQ(25U, offsets[0]);
  EXPECT_EQ(7U, offsets[1]);
  offsets.clear();
}

TEST(StringUtilTest, ReplaceStringPlaceholders) {
  std::vector<string16> subst;
  subst.push_back(ASCIIToUTF16("9a"));
  subst.push_back(ASCIIToUTF16("8b"));
  subst.push_back(ASCIIToUTF16("7c"));
  subst.push_back(ASCIIToUTF16("6d"));
  subst.push_back(ASCIIToUTF16("5e"));
  subst.push_back(ASCIIToUTF16("4f"));
  subst.push_back(ASCIIToUTF16("3g"));
  subst.push_back(ASCIIToUTF16("2h"));
  subst.push_back(ASCIIToUTF16("1i"));

  string16 formatted =
      ReplaceStringPlaceholders(
          ASCIIToUTF16("$1a,$2b,$3c,$4d,$5e,$6f,$7g,$8h,$9i"), subst, NULL);

  EXPECT_EQ(formatted, ASCIIToUTF16("9aa,8bb,7cc,6dd,5ee,4ff,3gg,2hh,1ii"));
}

TEST(StringUtilTest, ReplaceStringPlaceholdersTooFew) {
  // Test whether replacestringplaceholders works as expected when there
  // are fewer inputs than outputs.
  std::vector<string16> subst;
  subst.push_back(ASCIIToUTF16("9a"));
  subst.push_back(ASCIIToUTF16("8b"));
  subst.push_back(ASCIIToUTF16("7c"));

  string16 formatted =
      ReplaceStringPlaceholders(
          ASCIIToUTF16("$1a,$2b,$3c,$4d,$5e,$6f,$1g,$2h,$3i"), subst, NULL);

  EXPECT_EQ(formatted, ASCIIToUTF16("9aa,8bb,7cc,d,e,f,9ag,8bh,7ci"));
}

TEST(StringUtilTest, SplitStringAlongWhitespace) {
  struct TestData {
    const std::wstring input;
    const size_t expected_result_count;
    const std::wstring output1;
    const std::wstring output2;
  } data[] = {
    { L"a",       1, L"a",  L""   },
    { L" ",       0, L"",   L""   },
    { L" a",      1, L"a",  L""   },
    { L" ab ",    1, L"ab", L""   },
    { L" ab c",   2, L"ab", L"c"  },
    { L" ab c ",  2, L"ab", L"c"  },
    { L" ab cd",  2, L"ab", L"cd" },
    { L" ab cd ", 2, L"ab", L"cd" },
    { L" \ta\t",  1, L"a",  L""   },
    { L" b\ta\t", 2, L"b",  L"a"  },
    { L" b\tat",  2, L"b",  L"at" },
    { L"b\tat",   2, L"b",  L"at" },
    { L"b\t at",  2, L"b",  L"at" },
  };
  for (size_t i = 0; i < ARRAYSIZE_UNSAFE(data); ++i) {
    std::vector<std::wstring> results;
    SplitStringAlongWhitespace(data[i].input, &results);
    ASSERT_EQ(data[i].expected_result_count, results.size());
    if (data[i].expected_result_count > 0)
      ASSERT_EQ(data[i].output1, results[0]);
    if (data[i].expected_result_count > 1)
      ASSERT_EQ(data[i].output2, results[1]);
  }
}

TEST(StringUtilTest, MatchPatternTest) {
  EXPECT_EQ(MatchPattern(L"www.google.com", L"*.com"), true);
  EXPECT_EQ(MatchPattern(L"www.google.com", L"*"), true);
  EXPECT_EQ(MatchPattern(L"www.google.com", L"www*.g*.org"), false);
  EXPECT_EQ(MatchPattern(L"Hello", L"H?l?o"), true);
  EXPECT_EQ(MatchPattern(L"www.google.com", L"http://*)"), false);
  EXPECT_EQ(MatchPattern(L"www.msn.com", L"*.COM"), false);
  EXPECT_EQ(MatchPattern(L"Hello*1234", L"He??o\\*1*"), true);
  EXPECT_EQ(MatchPattern(L"", L"*.*"), false);
  EXPECT_EQ(MatchPattern(L"", L"*"), true);
  EXPECT_EQ(MatchPattern(L"", L"?"), true);
  EXPECT_EQ(MatchPattern(L"", L""), true);
  EXPECT_EQ(MatchPattern(L"Hello", L""), false);
  EXPECT_EQ(MatchPattern(L"Hello*", L"Hello*"), true);
  EXPECT_EQ(MatchPattern("Hello*", "Hello*"), true);  // narrow string
}

TEST(StringUtilTest, LcpyTest) {
  // Test the normal case where we fit in our buffer.
  {
    char dst[10];
    wchar_t wdst[10];
    EXPECT_EQ(7U, base::strlcpy(dst, "abcdefg", arraysize(dst)));
    EXPECT_EQ(0, memcmp(dst, "abcdefg", 8));
    EXPECT_EQ(7U, base::wcslcpy(wdst, L"abcdefg", arraysize(wdst)));
    EXPECT_EQ(0, memcmp(wdst, L"abcdefg", sizeof(wchar_t) * 8));
  }

  // Test dst_size == 0, nothing should be written to |dst| and we should
  // have the equivalent of strlen(src).
  {
    char dst[2] = {1, 2};
    wchar_t wdst[2] = {1, 2};
    EXPECT_EQ(7U, base::strlcpy(dst, "abcdefg", 0));
    EXPECT_EQ(1, dst[0]);
    EXPECT_EQ(2, dst[1]);
    EXPECT_EQ(7U, base::wcslcpy(wdst, L"abcdefg", 0));
#if defined(WCHAR_T_IS_UNSIGNED)
    EXPECT_EQ(1U, wdst[0]);
    EXPECT_EQ(2U, wdst[1]);
#else
    EXPECT_EQ(1, wdst[0]);
    EXPECT_EQ(2, wdst[1]);
#endif
  }

  // Test the case were we _just_ competely fit including the null.
  {
    char dst[8];
    wchar_t wdst[8];
    EXPECT_EQ(7U, base::strlcpy(dst, "abcdefg", arraysize(dst)));
    EXPECT_EQ(0, memcmp(dst, "abcdefg", 8));
    EXPECT_EQ(7U, base::wcslcpy(wdst, L"abcdefg", arraysize(wdst)));
    EXPECT_EQ(0, memcmp(wdst, L"abcdefg", sizeof(wchar_t) * 8));
  }

  // Test the case were we we are one smaller, so we can't fit the null.
  {
    char dst[7];
    wchar_t wdst[7];
    EXPECT_EQ(7U, base::strlcpy(dst, "abcdefg", arraysize(dst)));
    EXPECT_EQ(0, memcmp(dst, "abcdef", 7));
    EXPECT_EQ(7U, base::wcslcpy(wdst, L"abcdefg", arraysize(wdst)));
    EXPECT_EQ(0, memcmp(wdst, L"abcdef", sizeof(wchar_t) * 7));
  }

  // Test the case were we are just too small.
  {
    char dst[3];
    wchar_t wdst[3];
    EXPECT_EQ(7U, base::strlcpy(dst, "abcdefg", arraysize(dst)));
    EXPECT_EQ(0, memcmp(dst, "ab", 3));
    EXPECT_EQ(7U, base::wcslcpy(wdst, L"abcdefg", arraysize(wdst)));
    EXPECT_EQ(0, memcmp(wdst, L"ab", sizeof(wchar_t) * 3));
  }
}

TEST(StringUtilTest, WprintfFormatPortabilityTest) {
  struct TestData {
    const wchar_t* input;
    bool portable;
  } cases[] = {
    { L"%ls", true },
    { L"%s", false },
    { L"%S", false },
    { L"%lS", false },
    { L"Hello, %s", false },
    { L"%lc", true },
    { L"%c", false },
    { L"%C", false },
    { L"%lC", false },
    { L"%ls %s", false },
    { L"%s %ls", false },
    { L"%s %ls %s", false },
    { L"%f", true },
    { L"%f %F", false },
    { L"%d %D", false },
    { L"%o %O", false },
    { L"%u %U", false },
    { L"%f %d %o %u", true },
    { L"%-8d (%02.1f%)", true },
    { L"% 10s", false },
    { L"% 10ls", true }
  };
  for (size_t i = 0; i < ARRAYSIZE_UNSAFE(cases); ++i) {
    EXPECT_EQ(cases[i].portable, base::IsWprintfFormatPortable(cases[i].input));
  }
}

TEST(StringUtilTest, ElideString) {
  struct TestData {
    const wchar_t* input;
    int max_len;
    bool result;
    const wchar_t* output;
  } cases[] = {
    { L"Hello", 0, true, L"" },
    { L"", 0, false, L"" },
    { L"Hello, my name is Tom", 1, true, L"H" },
    { L"Hello, my name is Tom", 2, true, L"He" },
    { L"Hello, my name is Tom", 3, true, L"H.m" },
    { L"Hello, my name is Tom", 4, true, L"H..m" },
    { L"Hello, my name is Tom", 5, true, L"H...m" },
    { L"Hello, my name is Tom", 6, true, L"He...m" },
    { L"Hello, my name is Tom", 7, true, L"He...om" },
    { L"Hello, my name is Tom", 10, true, L"Hell...Tom" },
    { L"Hello, my name is Tom", 100, false, L"Hello, my name is Tom" }
  };
  for (size_t i = 0; i < ARRAYSIZE_UNSAFE(cases); ++i) {
    std::wstring output;
    EXPECT_EQ(cases[i].result,
              ElideString(cases[i].input, cases[i].max_len, &output));
    EXPECT_TRUE(output == cases[i].output);
  }
}

TEST(StringUtilTest, HexEncode) {
  std::string hex(HexEncode(NULL, 0));
  EXPECT_EQ(hex.length(), 0U);
  unsigned char bytes[] = {0x01, 0xff, 0x02, 0xfe, 0x03, 0x80, 0x81};
  hex = HexEncode(bytes, sizeof(bytes));
  EXPECT_EQ(hex.compare("01FF02FE038081"), 0);
}