// Copyright 2008, Google Inc.
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
//     * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
//     * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
// Authors: vladl@google.com (Vlad Losev), wan@google.com (Zhanyong Wan)
//
// This file tests the internal cross-platform support utilities.

#include <gtest/internal/gtest-port.h>
#include <gtest/gtest.h>
#include <gtest/gtest-spi.h>

// Indicates that this translation unit is part of Google Test's
// implementation.  It must come before gtest-internal-inl.h is
// included, or there will be a compiler error.  This trick is to
// prevent a user from accidentally including gtest-internal-inl.h in
// his code.
#define GTEST_IMPLEMENTATION_ 1
#include "src/gtest-internal-inl.h"
#undef GTEST_IMPLEMENTATION_

namespace testing {
namespace internal {

TEST(GtestCheckSyntaxTest, BehavesLikeASingleStatement) {
  if (false)
    GTEST_CHECK_(false) << "This should never be executed; "
                           "It's a compilation test only.";

  if (true)
    GTEST_CHECK_(true);
  else
    ;  // NOLINT

  if (false)
    ;  // NOLINT
  else
    GTEST_CHECK_(true) << "";
}

TEST(GtestCheckSyntaxTest, WorksWithSwitch) {
  switch (0) {
    case 1:
      break;
    default:
      GTEST_CHECK_(true);
  }

  switch(0)
    case 0:
      GTEST_CHECK_(true) << "Check failed in switch case";
}

#if GTEST_HAS_DEATH_TEST

TEST(GtestCheckDeathTest, DiesWithCorrectOutputOnFailure) {
  const bool a_false_condition = false;
  const char regex[] =
#ifdef _MSC_VER
     "gtest-port_test\\.cc\\(\\d+\\):"
#else
     "gtest-port_test\\.cc:[0-9]+"
#endif  // _MSC_VER
     ".*a_false_condition.*Extra info.*";

  EXPECT_DEATH(GTEST_CHECK_(a_false_condition) << "Extra info", regex);
}

TEST(GtestCheckDeathTest, LivesSilentlyOnSuccess) {
  EXPECT_EXIT({
      GTEST_CHECK_(true) << "Extra info";
      ::std::cerr << "Success\n";
      exit(0); },
      ::testing::ExitedWithCode(0), "Success");
}

#endif  // GTEST_HAS_DEATH_TEST

#if GTEST_USES_POSIX_RE

template <typename Str>
class RETest : public ::testing::Test {};

// Defines StringTypes as the list of all string types that class RE
// supports.
typedef testing::Types<
#if GTEST_HAS_STD_STRING
    ::std::string,
#endif  // GTEST_HAS_STD_STRING
#if GTEST_HAS_GLOBAL_STRING
    ::string,
#endif  // GTEST_HAS_GLOBAL_STRING
    const char*> StringTypes;

TYPED_TEST_CASE(RETest, StringTypes);

// Tests RE's implicit constructors.
TYPED_TEST(RETest, ImplicitConstructorWorks) {
  const RE empty(TypeParam(""));
  EXPECT_STREQ("", empty.pattern());

  const RE simple(TypeParam("hello"));
  EXPECT_STREQ("hello", simple.pattern());

  const RE normal(TypeParam(".*(\\w+)"));
  EXPECT_STREQ(".*(\\w+)", normal.pattern());
}

// Tests that RE's constructors reject invalid regular expressions.
TYPED_TEST(RETest, RejectsInvalidRegex) {
  EXPECT_NONFATAL_FAILURE({
    const RE invalid(TypeParam("?"));
  }, "\"?\" is not a valid POSIX Extended regular expression.");
}

// Tests RE::FullMatch().
TYPED_TEST(RETest, FullMatchWorks) {
  const RE empty(TypeParam(""));
  EXPECT_TRUE(RE::FullMatch(TypeParam(""), empty));
  EXPECT_FALSE(RE::FullMatch(TypeParam("a"), empty));

  const RE re(TypeParam("a.*z"));
  EXPECT_TRUE(RE::FullMatch(TypeParam("az"), re));
  EXPECT_TRUE(RE::FullMatch(TypeParam("axyz"), re));
  EXPECT_FALSE(RE::FullMatch(TypeParam("baz"), re));
  EXPECT_FALSE(RE::FullMatch(TypeParam("azy"), re));
}

// Tests RE::PartialMatch().
TYPED_TEST(RETest, PartialMatchWorks) {
  const RE empty(TypeParam(""));
  EXPECT_TRUE(RE::PartialMatch(TypeParam(""), empty));
  EXPECT_TRUE(RE::PartialMatch(TypeParam("a"), empty));

  const RE re(TypeParam("a.*z"));
  EXPECT_TRUE(RE::PartialMatch(TypeParam("az"), re));
  EXPECT_TRUE(RE::PartialMatch(TypeParam("axyz"), re));
  EXPECT_TRUE(RE::PartialMatch(TypeParam("baz"), re));
  EXPECT_TRUE(RE::PartialMatch(TypeParam("azy"), re));
  EXPECT_FALSE(RE::PartialMatch(TypeParam("zza"), re));
}

#elif GTEST_USES_SIMPLE_RE

TEST(IsInSetTest, NulCharIsNotInAnySet) {
  EXPECT_FALSE(IsInSet('\0', ""));
  EXPECT_FALSE(IsInSet('\0', "\0"));
  EXPECT_FALSE(IsInSet('\0', "a"));
}

TEST(IsInSetTest, WorksForNonNulChars) {
  EXPECT_FALSE(IsInSet('a', "Ab"));
  EXPECT_FALSE(IsInSet('c', ""));

  EXPECT_TRUE(IsInSet('b', "bcd"));
  EXPECT_TRUE(IsInSet('b', "ab"));
}

TEST(IsDigitTest, IsFalseForNonDigit) {
  EXPECT_FALSE(IsDigit('\0'));
  EXPECT_FALSE(IsDigit(' '));
  EXPECT_FALSE(IsDigit('+'));
  EXPECT_FALSE(IsDigit('-'));
  EXPECT_FALSE(IsDigit('.'));
  EXPECT_FALSE(IsDigit('a'));
}

TEST(IsDigitTest, IsTrueForDigit) {
  EXPECT_TRUE(IsDigit('0'));
  EXPECT_TRUE(IsDigit('1'));
  EXPECT_TRUE(IsDigit('5'));
  EXPECT_TRUE(IsDigit('9'));
}

TEST(IsPunctTest, IsFalseForNonPunct) {
  EXPECT_FALSE(IsPunct('\0'));
  EXPECT_FALSE(IsPunct(' '));
  EXPECT_FALSE(IsPunct('\n'));
  EXPECT_FALSE(IsPunct('a'));
  EXPECT_FALSE(IsPunct('0'));
}

TEST(IsPunctTest, IsTrueForPunct) {
  for (const char* p = "^-!\"#$%&'()*+,./:;<=>?@[\\]_`{|}~"; *p; p++) {
    EXPECT_PRED1(IsPunct, *p);
  }
}

TEST(IsRepeatTest, IsFalseForNonRepeatChar) {
  EXPECT_FALSE(IsRepeat('\0'));
  EXPECT_FALSE(IsRepeat(' '));
  EXPECT_FALSE(IsRepeat('a'));
  EXPECT_FALSE(IsRepeat('1'));
  EXPECT_FALSE(IsRepeat('-'));
}

TEST(IsRepeatTest, IsTrueForRepeatChar) {
  EXPECT_TRUE(IsRepeat('?'));
  EXPECT_TRUE(IsRepeat('*'));
  EXPECT_TRUE(IsRepeat('+'));
}

TEST(IsWhiteSpaceTest, IsFalseForNonWhiteSpace) {
  EXPECT_FALSE(IsWhiteSpace('\0'));
  EXPECT_FALSE(IsWhiteSpace('a'));
  EXPECT_FALSE(IsWhiteSpace('1'));
  EXPECT_FALSE(IsWhiteSpace('+'));
  EXPECT_FALSE(IsWhiteSpace('_'));
}

TEST(IsWhiteSpaceTest, IsTrueForWhiteSpace) {
  EXPECT_TRUE(IsWhiteSpace(' '));
  EXPECT_TRUE(IsWhiteSpace('\n'));
  EXPECT_TRUE(IsWhiteSpace('\r'));
  EXPECT_TRUE(IsWhiteSpace('\t'));
  EXPECT_TRUE(IsWhiteSpace('\v'));
  EXPECT_TRUE(IsWhiteSpace('\f'));
}

TEST(IsWordCharTest, IsFalseForNonWordChar) {
  EXPECT_FALSE(IsWordChar('\0'));
  EXPECT_FALSE(IsWordChar('+'));
  EXPECT_FALSE(IsWordChar('.'));
  EXPECT_FALSE(IsWordChar(' '));
  EXPECT_FALSE(IsWordChar('\n'));
}

TEST(IsWordCharTest, IsTrueForLetter) {
  EXPECT_TRUE(IsWordChar('a'));
  EXPECT_TRUE(IsWordChar('b'));
  EXPECT_TRUE(IsWordChar('A'));
  EXPECT_TRUE(IsWordChar('Z'));
}

TEST(IsWordCharTest, IsTrueForDigit) {
  EXPECT_TRUE(IsWordChar('0'));
  EXPECT_TRUE(IsWordChar('1'));
  EXPECT_TRUE(IsWordChar('7'));
  EXPECT_TRUE(IsWordChar('9'));
}

TEST(IsWordCharTest, IsTrueForUnderscore) {
  EXPECT_TRUE(IsWordChar('_'));
}

TEST(IsValidEscapeTest, IsFalseForNonPrintable) {
  EXPECT_FALSE(IsValidEscape('\0'));
  EXPECT_FALSE(IsValidEscape('\007'));
}

TEST(IsValidEscapeTest, IsFalseForDigit) {
  EXPECT_FALSE(IsValidEscape('0'));
  EXPECT_FALSE(IsValidEscape('9'));
}

TEST(IsValidEscapeTest, IsFalseForWhiteSpace) {
  EXPECT_FALSE(IsValidEscape(' '));
  EXPECT_FALSE(IsValidEscape('\n'));
}

TEST(IsValidEscapeTest, IsFalseForSomeLetter) {
  EXPECT_FALSE(IsValidEscape('a'));
  EXPECT_FALSE(IsValidEscape('Z'));
}

TEST(IsValidEscapeTest, IsTrueForPunct) {
  EXPECT_TRUE(IsValidEscape('.'));
  EXPECT_TRUE(IsValidEscape('-'));
  EXPECT_TRUE(IsValidEscape('^'));
  EXPECT_TRUE(IsValidEscape('$'));
  EXPECT_TRUE(IsValidEscape('('));
  EXPECT_TRUE(IsValidEscape(']'));
  EXPECT_TRUE(IsValidEscape('{'));
  EXPECT_TRUE(IsValidEscape('|'));
}

TEST(IsValidEscapeTest, IsTrueForSomeLetter) {
  EXPECT_TRUE(IsValidEscape('d'));
  EXPECT_TRUE(IsValidEscape('D'));
  EXPECT_TRUE(IsValidEscape('s'));
  EXPECT_TRUE(IsValidEscape('S'));
  EXPECT_TRUE(IsValidEscape('w'));
  EXPECT_TRUE(IsValidEscape('W'));
}

TEST(AtomMatchesCharTest, EscapedPunct) {
  EXPECT_FALSE(AtomMatchesChar(true, '\\', '\0'));
  EXPECT_FALSE(AtomMatchesChar(true, '\\', ' '));
  EXPECT_FALSE(AtomMatchesChar(true, '_', '.'));
  EXPECT_FALSE(AtomMatchesChar(true, '.', 'a'));

  EXPECT_TRUE(AtomMatchesChar(true, '\\', '\\'));
  EXPECT_TRUE(AtomMatchesChar(true, '_', '_'));
  EXPECT_TRUE(AtomMatchesChar(true, '+', '+'));
  EXPECT_TRUE(AtomMatchesChar(true, '.', '.'));
}

TEST(AtomMatchesCharTest, Escaped_d) {
  EXPECT_FALSE(AtomMatchesChar(true, 'd', '\0'));
  EXPECT_FALSE(AtomMatchesChar(true, 'd', 'a'));
  EXPECT_FALSE(AtomMatchesChar(true, 'd', '.'));

  EXPECT_TRUE(AtomMatchesChar(true, 'd', '0'));
  EXPECT_TRUE(AtomMatchesChar(true, 'd', '9'));
}

TEST(AtomMatchesCharTest, Escaped_D) {
  EXPECT_FALSE(AtomMatchesChar(true, 'D', '0'));
  EXPECT_FALSE(AtomMatchesChar(true, 'D', '9'));

  EXPECT_TRUE(AtomMatchesChar(true, 'D', '\0'));
  EXPECT_TRUE(AtomMatchesChar(true, 'D', 'a'));
  EXPECT_TRUE(AtomMatchesChar(true, 'D', '-'));
}

TEST(AtomMatchesCharTest, Escaped_s) {
  EXPECT_FALSE(AtomMatchesChar(true, 's', '\0'));
  EXPECT_FALSE(AtomMatchesChar(true, 's', 'a'));
  EXPECT_FALSE(AtomMatchesChar(true, 's', '.'));
  EXPECT_FALSE(AtomMatchesChar(true, 's', '9'));

  EXPECT_TRUE(AtomMatchesChar(true, 's', ' '));
  EXPECT_TRUE(AtomMatchesChar(true, 's', '\n'));
  EXPECT_TRUE(AtomMatchesChar(true, 's', '\t'));
}

TEST(AtomMatchesCharTest, Escaped_S) {
  EXPECT_FALSE(AtomMatchesChar(true, 'S', ' '));
  EXPECT_FALSE(AtomMatchesChar(true, 'S', '\r'));

  EXPECT_TRUE(AtomMatchesChar(true, 'S', '\0'));
  EXPECT_TRUE(AtomMatchesChar(true, 'S', 'a'));
  EXPECT_TRUE(AtomMatchesChar(true, 'S', '9'));
}

TEST(AtomMatchesCharTest, Escaped_w) {
  EXPECT_FALSE(AtomMatchesChar(true, 'w', '\0'));
  EXPECT_FALSE(AtomMatchesChar(true, 'w', '+'));
  EXPECT_FALSE(AtomMatchesChar(true, 'w', ' '));
  EXPECT_FALSE(AtomMatchesChar(true, 'w', '\n'));

  EXPECT_TRUE(AtomMatchesChar(true, 'w', '0'));
  EXPECT_TRUE(AtomMatchesChar(true, 'w', 'b'));
  EXPECT_TRUE(AtomMatchesChar(true, 'w', 'C'));
  EXPECT_TRUE(AtomMatchesChar(true, 'w', '_'));
}

TEST(AtomMatchesCharTest, Escaped_W) {
  EXPECT_FALSE(AtomMatchesChar(true, 'W', 'A'));
  EXPECT_FALSE(AtomMatchesChar(true, 'W', 'b'));
  EXPECT_FALSE(AtomMatchesChar(true, 'W', '9'));
  EXPECT_FALSE(AtomMatchesChar(true, 'W', '_'));

  EXPECT_TRUE(AtomMatchesChar(true, 'W', '\0'));
  EXPECT_TRUE(AtomMatchesChar(true, 'W', '*'));
  EXPECT_TRUE(AtomMatchesChar(true, 'W', '\n'));
}

TEST(AtomMatchesCharTest, EscapedWhiteSpace) {
  EXPECT_FALSE(AtomMatchesChar(true, 'f', '\0'));
  EXPECT_FALSE(AtomMatchesChar(true, 'f', '\n'));
  EXPECT_FALSE(AtomMatchesChar(true, 'n', '\0'));
  EXPECT_FALSE(AtomMatchesChar(true, 'n', '\r'));
  EXPECT_FALSE(AtomMatchesChar(true, 'r', '\0'));
  EXPECT_FALSE(AtomMatchesChar(true, 'r', 'a'));
  EXPECT_FALSE(AtomMatchesChar(true, 't', '\0'));
  EXPECT_FALSE(AtomMatchesChar(true, 't', 't'));
  EXPECT_FALSE(AtomMatchesChar(true, 'v', '\0'));
  EXPECT_FALSE(AtomMatchesChar(true, 'v', '\f'));

  EXPECT_TRUE(AtomMatchesChar(true, 'f', '\f'));
  EXPECT_TRUE(AtomMatchesChar(true, 'n', '\n'));
  EXPECT_TRUE(AtomMatchesChar(true, 'r', '\r'));
  EXPECT_TRUE(AtomMatchesChar(true, 't', '\t'));
  EXPECT_TRUE(AtomMatchesChar(true, 'v', '\v'));
}

TEST(AtomMatchesCharTest, UnescapedDot) {
  EXPECT_FALSE(AtomMatchesChar(false, '.', '\n'));

  EXPECT_TRUE(AtomMatchesChar(false, '.', '\0'));
  EXPECT_TRUE(AtomMatchesChar(false, '.', '.'));
  EXPECT_TRUE(AtomMatchesChar(false, '.', 'a'));
  EXPECT_TRUE(AtomMatchesChar(false, '.', ' '));
}

TEST(AtomMatchesCharTest, UnescapedChar) {
  EXPECT_FALSE(AtomMatchesChar(false, 'a', '\0'));
  EXPECT_FALSE(AtomMatchesChar(false, 'a', 'b'));
  EXPECT_FALSE(AtomMatchesChar(false, '$', 'a'));

  EXPECT_TRUE(AtomMatchesChar(false, '$', '$'));
  EXPECT_TRUE(AtomMatchesChar(false, '5', '5'));
  EXPECT_TRUE(AtomMatchesChar(false, 'Z', 'Z'));
}

TEST(ValidateRegexTest, GeneratesFailureAndReturnsFalseForInvalid) {
  EXPECT_NONFATAL_FAILURE(ASSERT_FALSE(ValidateRegex(NULL)),
                          "NULL is not a valid simple regular expression");
  EXPECT_NONFATAL_FAILURE(
      ASSERT_FALSE(ValidateRegex("a\\")),
      "Syntax error at index 1 in simple regular expression \"a\\\": ");
  EXPECT_NONFATAL_FAILURE(ASSERT_FALSE(ValidateRegex("a\\")),
                          "'\\' cannot appear at the end");
  EXPECT_NONFATAL_FAILURE(ASSERT_FALSE(ValidateRegex("\\n\\")),
                          "'\\' cannot appear at the end");
  EXPECT_NONFATAL_FAILURE(ASSERT_FALSE(ValidateRegex("\\s\\hb")),
                          "invalid escape sequence \"\\h\"");
  EXPECT_NONFATAL_FAILURE(ASSERT_FALSE(ValidateRegex("^^")),
                          "'^' can only appear at the beginning");
  EXPECT_NONFATAL_FAILURE(ASSERT_FALSE(ValidateRegex(".*^b")),
                          "'^' can only appear at the beginning");
  EXPECT_NONFATAL_FAILURE(ASSERT_FALSE(ValidateRegex("$$")),
                          "'$' can only appear at the end");
  EXPECT_NONFATAL_FAILURE(ASSERT_FALSE(ValidateRegex("^$a")),
                          "'$' can only appear at the end");
  EXPECT_NONFATAL_FAILURE(ASSERT_FALSE(ValidateRegex("a(b")),
                          "'(' is unsupported");
  EXPECT_NONFATAL_FAILURE(ASSERT_FALSE(ValidateRegex("ab)")),
                          "')' is unsupported");
  EXPECT_NONFATAL_FAILURE(ASSERT_FALSE(ValidateRegex("[ab")),
                          "'[' is unsupported");
  EXPECT_NONFATAL_FAILURE(ASSERT_FALSE(ValidateRegex("a{2")),
                          "'{' is unsupported");
  EXPECT_NONFATAL_FAILURE(ASSERT_FALSE(ValidateRegex("?")),
                          "'?' can only follow a repeatable token");
  EXPECT_NONFATAL_FAILURE(ASSERT_FALSE(ValidateRegex("^*")),
                          "'*' can only follow a repeatable token");
  EXPECT_NONFATAL_FAILURE(ASSERT_FALSE(ValidateRegex("5*+")),
                          "'+' can only follow a repeatable token");
}

TEST(ValidateRegexTest, ReturnsTrueForValid) {
  EXPECT_TRUE(ValidateRegex(""));
  EXPECT_TRUE(ValidateRegex("a"));
  EXPECT_TRUE(ValidateRegex(".*"));
  EXPECT_TRUE(ValidateRegex("^a_+"));
  EXPECT_TRUE(ValidateRegex("^a\\t\\&?"));
  EXPECT_TRUE(ValidateRegex("09*$"));
  EXPECT_TRUE(ValidateRegex("^Z$"));
  EXPECT_TRUE(ValidateRegex("a\\^Z\\$\\(\\)\\|\\[\\]\\{\\}"));
}

TEST(MatchRepetitionAndRegexAtHeadTest, WorksForZeroOrOne) {
  EXPECT_FALSE(MatchRepetitionAndRegexAtHead(false, 'a', '?', "a", "ba"));
  // Repeating more than once.
  EXPECT_FALSE(MatchRepetitionAndRegexAtHead(false, 'a', '?', "b", "aab"));

  // Repeating zero times.
  EXPECT_TRUE(MatchRepetitionAndRegexAtHead(false, 'a', '?', "b", "ba"));
  // Repeating once.
  EXPECT_TRUE(MatchRepetitionAndRegexAtHead(false, 'a', '?', "b", "ab"));
  EXPECT_TRUE(MatchRepetitionAndRegexAtHead(false, '#', '?', ".", "##"));
}

TEST(MatchRepetitionAndRegexAtHeadTest, WorksForZeroOrMany) {
  EXPECT_FALSE(MatchRepetitionAndRegexAtHead(false, '.', '*', "a$", "baab"));

  // Repeating zero times.
  EXPECT_TRUE(MatchRepetitionAndRegexAtHead(false, '.', '*', "b", "bc"));
  // Repeating once.
  EXPECT_TRUE(MatchRepetitionAndRegexAtHead(false, '.', '*', "b", "abc"));
  // Repeating more than once.
  EXPECT_TRUE(MatchRepetitionAndRegexAtHead(true, 'w', '*', "-", "ab_1-g"));
}

TEST(MatchRepetitionAndRegexAtHeadTest, WorksForOneOrMany) {
  EXPECT_FALSE(MatchRepetitionAndRegexAtHead(false, '.', '+', "a$", "baab"));
  // Repeating zero times.
  EXPECT_FALSE(MatchRepetitionAndRegexAtHead(false, '.', '+', "b", "bc"));

  // Repeating once.
  EXPECT_TRUE(MatchRepetitionAndRegexAtHead(false, '.', '+', "b", "abc"));
  // Repeating more than once.
  EXPECT_TRUE(MatchRepetitionAndRegexAtHead(true, 'w', '+', "-", "ab_1-g"));
}

TEST(MatchRegexAtHeadTest, ReturnsTrueForEmptyRegex) {
  EXPECT_TRUE(MatchRegexAtHead("", ""));
  EXPECT_TRUE(MatchRegexAtHead("", "ab"));
}

TEST(MatchRegexAtHeadTest, WorksWhenDollarIsInRegex) {
  EXPECT_FALSE(MatchRegexAtHead("$", "a"));

  EXPECT_TRUE(MatchRegexAtHead("$", ""));
  EXPECT_TRUE(MatchRegexAtHead("a$", "a"));
}

TEST(MatchRegexAtHeadTest, WorksWhenRegexStartsWithEscapeSequence) {
  EXPECT_FALSE(MatchRegexAtHead("\\w", "+"));
  EXPECT_FALSE(MatchRegexAtHead("\\W", "ab"));

  EXPECT_TRUE(MatchRegexAtHead("\\sa", "\nab"));
  EXPECT_TRUE(MatchRegexAtHead("\\d", "1a"));
}

TEST(MatchRegexAtHeadTest, WorksWhenRegexStartsWithRepetition) {
  EXPECT_FALSE(MatchRegexAtHead(".+a", "abc"));
  EXPECT_FALSE(MatchRegexAtHead("a?b", "aab"));

  EXPECT_TRUE(MatchRegexAtHead(".*a", "bc12-ab"));
  EXPECT_TRUE(MatchRegexAtHead("a?b", "b"));
  EXPECT_TRUE(MatchRegexAtHead("a?b", "ab"));
}

TEST(MatchRegexAtHeadTest,
     WorksWhenRegexStartsWithRepetionOfEscapeSequence) {
  EXPECT_FALSE(MatchRegexAtHead("\\.+a", "abc"));
  EXPECT_FALSE(MatchRegexAtHead("\\s?b", "  b"));

  EXPECT_TRUE(MatchRegexAtHead("\\(*a", "((((ab"));
  EXPECT_TRUE(MatchRegexAtHead("\\^?b", "^b"));
  EXPECT_TRUE(MatchRegexAtHead("\\\\?b", "b"));
  EXPECT_TRUE(MatchRegexAtHead("\\\\?b", "\\b"));
}

TEST(MatchRegexAtHeadTest, MatchesSequentially) {
  EXPECT_FALSE(MatchRegexAtHead("ab.*c", "acabc"));

  EXPECT_TRUE(MatchRegexAtHead("ab.*c", "ab-fsc"));
}

TEST(MatchRegexAnywhereTest, ReturnsFalseWhenStringIsNull) {
  EXPECT_FALSE(MatchRegexAnywhere("", NULL));
}

TEST(MatchRegexAnywhereTest, WorksWhenRegexStartsWithCaret) {
  EXPECT_FALSE(MatchRegexAnywhere("^a", "ba"));
  EXPECT_FALSE(MatchRegexAnywhere("^$", "a"));

  EXPECT_TRUE(MatchRegexAnywhere("^a", "ab"));
  EXPECT_TRUE(MatchRegexAnywhere("^", "ab"));
  EXPECT_TRUE(MatchRegexAnywhere("^$", ""));
}

TEST(MatchRegexAnywhereTest, ReturnsFalseWhenNoMatch) {
  EXPECT_FALSE(MatchRegexAnywhere("a", "bcde123"));
  EXPECT_FALSE(MatchRegexAnywhere("a.+a", "--aa88888888"));
}

TEST(MatchRegexAnywhereTest, ReturnsTrueWhenMatchingPrefix) {
  EXPECT_TRUE(MatchRegexAnywhere("\\w+", "ab1_ - 5"));
  EXPECT_TRUE(MatchRegexAnywhere(".*=", "="));
  EXPECT_TRUE(MatchRegexAnywhere("x.*ab?.*bc", "xaaabc"));
}

TEST(MatchRegexAnywhereTest, ReturnsTrueWhenMatchingNonPrefix) {
  EXPECT_TRUE(MatchRegexAnywhere("\\w+", "$$$ ab1_ - 5"));
  EXPECT_TRUE(MatchRegexAnywhere("\\.+=", "=  ...="));
}

// Tests RE's implicit constructors.
TEST(RETest, ImplicitConstructorWorks) {
  const RE empty("");
  EXPECT_STREQ("", empty.pattern());

  const RE simple("hello");
  EXPECT_STREQ("hello", simple.pattern());
}

// Tests that RE's constructors reject invalid regular expressions.
TEST(RETest, RejectsInvalidRegex) {
  EXPECT_NONFATAL_FAILURE({
    const RE normal(NULL);
  }, "NULL is not a valid simple regular expression");

  EXPECT_NONFATAL_FAILURE({
    const RE normal(".*(\\w+");
  }, "'(' is unsupported");

  EXPECT_NONFATAL_FAILURE({
    const RE invalid("^?");
  }, "'?' can only follow a repeatable token");
}

// Tests RE::FullMatch().
TEST(RETest, FullMatchWorks) {
  const RE empty("");
  EXPECT_TRUE(RE::FullMatch("", empty));
  EXPECT_FALSE(RE::FullMatch("a", empty));

  const RE re1("a");
  EXPECT_TRUE(RE::FullMatch("a", re1));

  const RE re("a.*z");
  EXPECT_TRUE(RE::FullMatch("az", re));
  EXPECT_TRUE(RE::FullMatch("axyz", re));
  EXPECT_FALSE(RE::FullMatch("baz", re));
  EXPECT_FALSE(RE::FullMatch("azy", re));
}

// Tests RE::PartialMatch().
TEST(RETest, PartialMatchWorks) {
  const RE empty("");
  EXPECT_TRUE(RE::PartialMatch("", empty));
  EXPECT_TRUE(RE::PartialMatch("a", empty));

  const RE re("a.*z");
  EXPECT_TRUE(RE::PartialMatch("az", re));
  EXPECT_TRUE(RE::PartialMatch("axyz", re));
  EXPECT_TRUE(RE::PartialMatch("baz", re));
  EXPECT_TRUE(RE::PartialMatch("azy", re));
  EXPECT_FALSE(RE::PartialMatch("zza", re));
}

#endif  // GTEST_USES_POSIX_RE

#if GTEST_HAS_STD_STRING

TEST(CaptureStderrTest, CapturesStdErr) {
  CaptureStderr();
  fprintf(stderr, "abc");
  ASSERT_EQ("abc", GetCapturedStderr());
}

#endif  // GTEST_HAS_STD_STRING

}  // namespace internal
}  // namespace testing