text: // Copyright (c) 2012 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 <string>
  
  #include "base/strings/string16.h"
  #include "base/strings/string_piece.h"
  #include "base/strings/utf_string_conversions.h"
  #include "testing/gtest/include/gtest/gtest.h"
  
  namespace base {
  
  template <typename T>
  class CommonStringPieceTest : public ::testing::Test {
   public:
    static const T as_string(const char* input) {
      return T(input);
    }
    static const T& as_string(const T& input) {
      return input;
    }
  };
  
  template <>
  class CommonStringPieceTest<string16> : public ::testing::Test {
   public:
    static const string16 as_string(const char* input) {
      return ASCIIToUTF16(input);
    }
    static const string16 as_string(const std::string& input) {
      return ASCIIToUTF16(input);
    }
  };
  
  typedef ::testing::Types<std::string, string16> SupportedStringTypes;
  
  TYPED_TEST_CASE(CommonStringPieceTest, SupportedStringTypes);
  
  TYPED_TEST(CommonStringPieceTest, CheckComparisonOperators) {
  #define CMP_Y(op, x, y)                                                    \
    {                                                                        \
      TypeParam lhs(TestFixture::as_string(x));                              \
      TypeParam rhs(TestFixture::as_string(y));                              \
      ASSERT_TRUE( (BasicStringPiece<TypeParam>((lhs.c_str())) op            \
                    BasicStringPiece<TypeParam>((rhs.c_str()))));            \
      ASSERT_TRUE( (BasicStringPiece<TypeParam>((lhs.c_str())).compare(      \
                        BasicStringPiece<TypeParam>((rhs.c_str()))) op 0));  \
    }
  
  #define CMP_N(op, x, y)                                                    \
    {                                                                        \
      TypeParam lhs(TestFixture::as_string(x));                              \
      TypeParam rhs(TestFixture::as_string(y));                              \
      ASSERT_FALSE( (BasicStringPiece<TypeParam>((lhs.c_str())) op           \
                    BasicStringPiece<TypeParam>((rhs.c_str()))));            \
      ASSERT_FALSE( (BasicStringPiece<TypeParam>((lhs.c_str())).compare(     \
                        BasicStringPiece<TypeParam>((rhs.c_str()))) op 0));  \
    }
  
    CMP_Y(==, "",   "");
    CMP_Y(==, "a",  "a");
    CMP_Y(==, "aa", "aa");
    CMP_N(==, "a",  "");
    CMP_N(==, "",   "a");
    CMP_N(==, "a",  "b");
    CMP_N(==, "a",  "aa");
    CMP_N(==, "aa", "a");
  
    CMP_N(!=, "",   "");
    CMP_N(!=, "a",  "a");
    CMP_N(!=, "aa", "aa");
    CMP_Y(!=, "a",  "");
    CMP_Y(!=, "",   "a");
    CMP_Y(!=, "a",  "b");
    CMP_Y(!=, "a",  "aa");
    CMP_Y(!=, "aa", "a");
  
    CMP_Y(<, "a",  "b");
    CMP_Y(<, "a",  "aa");
    CMP_Y(<, "aa", "b");
    CMP_Y(<, "aa", "bb");
    CMP_N(<, "a",  "a");
    CMP_N(<, "b",  "a");
    CMP_N(<, "aa", "a");
    CMP_N(<, "b",  "aa");
    CMP_N(<, "bb", "aa");
  
    CMP_Y(<=, "a",  "a");
    CMP_Y(<=, "a",  "b");
    CMP_Y(<=, "a",  "aa");
    CMP_Y(<=, "aa", "b");
    CMP_Y(<=, "aa", "bb");
    CMP_N(<=, "b",  "a");
    CMP_N(<=, "aa", "a");
    CMP_N(<=, "b",  "aa");
    CMP_N(<=, "bb", "aa");
  
    CMP_N(>=, "a",  "b");
    CMP_N(>=, "a",  "aa");
    CMP_N(>=, "aa", "b");
    CMP_N(>=, "aa", "bb");
    CMP_Y(>=, "a",  "a");
    CMP_Y(>=, "b",  "a");
    CMP_Y(>=, "aa", "a");
    CMP_Y(>=, "b",  "aa");
    CMP_Y(>=, "bb", "aa");
  
    CMP_N(>, "a",  "a");
    CMP_N(>, "a",  "b");
    CMP_N(>, "a",  "aa");
    CMP_N(>, "aa", "b");
    CMP_N(>, "aa", "bb");
    CMP_Y(>, "b",  "a");
    CMP_Y(>, "aa", "a");
    CMP_Y(>, "b",  "aa");
    CMP_Y(>, "bb", "aa");
  
    std::string x;
    for (int i = 0; i < 256; i++) {
      x += 'a';
      std::string y = x;
      CMP_Y(==, x, y);
      for (int j = 0; j < i; j++) {
        std::string z = x;
        z[j] = 'b';       // Differs in position 'j'
        CMP_N(==, x, z);
      }
    }
  
  #undef CMP_Y
  #undef CMP_N
  }
  
  TYPED_TEST(CommonStringPieceTest, CheckSTL) {
    TypeParam alphabet(TestFixture::as_string("abcdefghijklmnopqrstuvwxyz"));
    TypeParam abc(TestFixture::as_string("abc"));
    TypeParam xyz(TestFixture::as_string("xyz"));
    TypeParam foobar(TestFixture::as_string("foobar"));
  
    BasicStringPiece<TypeParam> a(alphabet);
    BasicStringPiece<TypeParam> b(abc);
    BasicStringPiece<TypeParam> c(xyz);
    BasicStringPiece<TypeParam> d(foobar);
    BasicStringPiece<TypeParam> e;
    TypeParam temp(TestFixture::as_string("123"));
    temp += static_cast<typename TypeParam::value_type>(0);
    temp += TestFixture::as_string("456");
    BasicStringPiece<TypeParam> f(temp);
  
    ASSERT_EQ(a[6], static_cast<typename TypeParam::value_type>('g'));
    ASSERT_EQ(b[0], static_cast<typename TypeParam::value_type>('a'));
    ASSERT_EQ(c[2], static_cast<typename TypeParam::value_type>('z'));
    ASSERT_EQ(f[3], static_cast<typename TypeParam::value_type>('\0'));
    ASSERT_EQ(f[5], static_cast<typename TypeParam::value_type>('5'));
  
    ASSERT_EQ(*d.data(), static_cast<typename TypeParam::value_type>('f'));
    ASSERT_EQ(d.data()[5], static_cast<typename TypeParam::value_type>('r'));
    ASSERT_TRUE(e.data() == NULL);
  
    ASSERT_EQ(*a.begin(), static_cast<typename TypeParam::value_type>('a'));
    ASSERT_EQ(*(b.begin() + 2), static_cast<typename TypeParam::value_type>('c'));
    ASSERT_EQ(*(c.end() - 1), static_cast<typename TypeParam::value_type>('z'));
  
    ASSERT_EQ(*a.rbegin(), static_cast<typename TypeParam::value_type>('z'));
    ASSERT_EQ(*(b.rbegin() + 2),
              static_cast<typename TypeParam::value_type>('a'));
    ASSERT_EQ(*(c.rend() - 1), static_cast<typename TypeParam::value_type>('x'));
    ASSERT_TRUE(a.rbegin() + 26 == a.rend());
  
    ASSERT_EQ(a.size(), 26U);
    ASSERT_EQ(b.size(), 3U);
    ASSERT_EQ(c.size(), 3U);
    ASSERT_EQ(d.size(), 6U);
    ASSERT_EQ(e.size(), 0U);
    ASSERT_EQ(f.size(), 7U);
  
    ASSERT_TRUE(!d.empty());
    ASSERT_TRUE(d.begin() != d.end());
    ASSERT_TRUE(d.begin() + 6 == d.end());
  
    ASSERT_TRUE(e.empty());
    ASSERT_TRUE(e.begin() == e.end());
  
    d.clear();
    ASSERT_EQ(d.size(), 0U);
    ASSERT_TRUE(d.empty());
    ASSERT_TRUE(d.data() == NULL);
    ASSERT_TRUE(d.begin() == d.end());
  
    ASSERT_GE(a.max_size(), a.capacity());
    ASSERT_GE(a.capacity(), a.size());
  }
  
  TYPED_TEST(CommonStringPieceTest, CheckFind) {
    typedef BasicStringPiece<TypeParam> Piece;
  
    TypeParam alphabet(TestFixture::as_string("abcdefghijklmnopqrstuvwxyz"));
    TypeParam abc(TestFixture::as_string("abc"));
    TypeParam xyz(TestFixture::as_string("xyz"));
    TypeParam foobar(TestFixture::as_string("foobar"));
  
    BasicStringPiece<TypeParam> a(alphabet);
    BasicStringPiece<TypeParam> b(abc);
    BasicStringPiece<TypeParam> c(xyz);
    BasicStringPiece<TypeParam> d(foobar);
  
    d.clear();
    Piece e;
    TypeParam temp(TestFixture::as_string("123"));
    temp.push_back('\0');
    temp += TestFixture::as_string("456");
    Piece f(temp);
  
    typename TypeParam::value_type buf[4] = { '%', '%', '%', '%' };
    ASSERT_EQ(a.copy(buf, 4), 4U);
    ASSERT_EQ(buf[0], a[0]);
    ASSERT_EQ(buf[1], a[1]);
    ASSERT_EQ(buf[2], a[2]);
    ASSERT_EQ(buf[3], a[3]);
    ASSERT_EQ(a.copy(buf, 3, 7), 3U);
    ASSERT_EQ(buf[0], a[7]);
    ASSERT_EQ(buf[1], a[8]);
    ASSERT_EQ(buf[2], a[9]);
    ASSERT_EQ(buf[3], a[3]);
    ASSERT_EQ(c.copy(buf, 99), 3U);
    ASSERT_EQ(buf[0], c[0]);
    ASSERT_EQ(buf[1], c[1]);
    ASSERT_EQ(buf[2], c[2]);
    ASSERT_EQ(buf[3], a[3]);
  
    ASSERT_EQ(Piece::npos, TypeParam::npos);
  
    ASSERT_EQ(a.find(b), 0U);
    ASSERT_EQ(a.find(b, 1), Piece::npos);
    ASSERT_EQ(a.find(c), 23U);
    ASSERT_EQ(a.find(c, 9), 23U);
    ASSERT_EQ(a.find(c, Piece::npos), Piece::npos);
    ASSERT_EQ(b.find(c), Piece::npos);
    ASSERT_EQ(b.find(c, Piece::npos), Piece::npos);
    ASSERT_EQ(a.find(d), 0U);
    ASSERT_EQ(a.find(e), 0U);
    ASSERT_EQ(a.find(d, 12), 12U);
    ASSERT_EQ(a.find(e, 17), 17U);
    TypeParam not_found(TestFixture::as_string("xx not found bb"));
    Piece g(not_found);
    ASSERT_EQ(a.find(g), Piece::npos);
    // empty string nonsense
    ASSERT_EQ(d.find(b), Piece::npos);
    ASSERT_EQ(e.find(b), Piece::npos);
    ASSERT_EQ(d.find(b, 4), Piece::npos);
    ASSERT_EQ(e.find(b, 7), Piece::npos);
  
    size_t empty_search_pos = TypeParam().find(TypeParam());
    ASSERT_EQ(d.find(d), empty_search_pos);
    ASSERT_EQ(d.find(e), empty_search_pos);
    ASSERT_EQ(e.find(d), empty_search_pos);
    ASSERT_EQ(e.find(e), empty_search_pos);
    ASSERT_EQ(d.find(d, 4), std::string().find(std::string(), 4));
    ASSERT_EQ(d.find(e, 4), std::string().find(std::string(), 4));
    ASSERT_EQ(e.find(d, 4), std::string().find(std::string(), 4));
    ASSERT_EQ(e.find(e, 4), std::string().find(std::string(), 4));
  
    ASSERT_EQ(a.find('a'), 0U);
    ASSERT_EQ(a.find('c'), 2U);
    ASSERT_EQ(a.find('z'), 25U);
    ASSERT_EQ(a.find('$'), Piece::npos);
    ASSERT_EQ(a.find('\0'), Piece::npos);
    ASSERT_EQ(f.find('\0'), 3U);
    ASSERT_EQ(f.find('3'), 2U);
    ASSERT_EQ(f.find('5'), 5U);
    ASSERT_EQ(g.find('o'), 4U);
    ASSERT_EQ(g.find('o', 4), 4U);
    ASSERT_EQ(g.find('o', 5), 8U);
    ASSERT_EQ(a.find('b', 5), Piece::npos);
    // empty string nonsense
    ASSERT_EQ(d.find('\0'), Piece::npos);
    ASSERT_EQ(e.find('\0'), Piece::npos);
    ASSERT_EQ(d.find('\0', 4), Piece::npos);
    ASSERT_EQ(e.find('\0', 7), Piece::npos);
    ASSERT_EQ(d.find('x'), Piece::npos);
    ASSERT_EQ(e.find('x'), Piece::npos);
    ASSERT_EQ(d.find('x', 4), Piece::npos);
    ASSERT_EQ(e.find('x', 7), Piece::npos);
  
    ASSERT_EQ(a.rfind(b), 0U);
    ASSERT_EQ(a.rfind(b, 1), 0U);
    ASSERT_EQ(a.rfind(c), 23U);
    ASSERT_EQ(a.rfind(c, 22U), Piece::npos);
    ASSERT_EQ(a.rfind(c, 1U), Piece::npos);
    ASSERT_EQ(a.rfind(c, 0U), Piece::npos);
    ASSERT_EQ(b.rfind(c), Piece::npos);
    ASSERT_EQ(b.rfind(c, 0U), Piece::npos);
    ASSERT_EQ(a.rfind(d), static_cast<size_t>(a.as_string().rfind(TypeParam())));
    ASSERT_EQ(a.rfind(e), a.as_string().rfind(TypeParam()));
    ASSERT_EQ(a.rfind(d, 12), 12U);
    ASSERT_EQ(a.rfind(e, 17), 17U);
    ASSERT_EQ(a.rfind(g), Piece::npos);
    ASSERT_EQ(d.rfind(b), Piece::npos);
    ASSERT_EQ(e.rfind(b), Piece::npos);
    ASSERT_EQ(d.rfind(b, 4), Piece::npos);
    ASSERT_EQ(e.rfind(b, 7), Piece::npos);
    // empty string nonsense
    ASSERT_EQ(d.rfind(d, 4), std::string().rfind(std::string()));
    ASSERT_EQ(e.rfind(d, 7), std::string().rfind(std::string()));
    ASSERT_EQ(d.rfind(e, 4), std::string().rfind(std::string()));
    ASSERT_EQ(e.rfind(e, 7), std::string().rfind(std::string()));
    ASSERT_EQ(d.rfind(d), std::string().rfind(std::string()));
    ASSERT_EQ(e.rfind(d), std::string().rfind(std::string()));
    ASSERT_EQ(d.rfind(e), std::string().rfind(std::string()));
    ASSERT_EQ(e.rfind(e), std::string().rfind(std::string()));
  
    ASSERT_EQ(g.rfind('o'), 8U);
    ASSERT_EQ(g.rfind('q'), Piece::npos);
    ASSERT_EQ(g.rfind('o', 8), 8U);
    ASSERT_EQ(g.rfind('o', 7), 4U);
    ASSERT_EQ(g.rfind('o', 3), Piece::npos);
    ASSERT_EQ(f.rfind('\0'), 3U);
    ASSERT_EQ(f.rfind('\0', 12), 3U);
    ASSERT_EQ(f.rfind('3'), 2U);
    ASSERT_EQ(f.rfind('5'), 5U);
    // empty string nonsense
    ASSERT_EQ(d.rfind('o'), Piece::npos);
    ASSERT_EQ(e.rfind('o'), Piece::npos);
    ASSERT_EQ(d.rfind('o', 4), Piece::npos);
    ASSERT_EQ(e.rfind('o', 7), Piece::npos);
  
    TypeParam one_two_three_four(TestFixture::as_string("one,two:three;four"));
    TypeParam comma_colon(TestFixture::as_string(",:"));
    ASSERT_EQ(3U, Piece(one_two_three_four).find_first_of(comma_colon));
    ASSERT_EQ(a.find_first_of(b), 0U);
    ASSERT_EQ(a.find_first_of(b, 0), 0U);
    ASSERT_EQ(a.find_first_of(b, 1), 1U);
    ASSERT_EQ(a.find_first_of(b, 2), 2U);
    ASSERT_EQ(a.find_first_of(b, 3), Piece::npos);
    ASSERT_EQ(a.find_first_of(c), 23U);
    ASSERT_EQ(a.find_first_of(c, 23), 23U);
    ASSERT_EQ(a.find_first_of(c, 24), 24U);
    ASSERT_EQ(a.find_first_of(c, 25), 25U);
    ASSERT_EQ(a.find_first_of(c, 26), Piece::npos);
    ASSERT_EQ(g.find_first_of(b), 13U);
    ASSERT_EQ(g.find_first_of(c), 0U);
    ASSERT_EQ(a.find_first_of(f), Piece::npos);
    ASSERT_EQ(f.find_first_of(a), Piece::npos);
    // empty string nonsense
    ASSERT_EQ(a.find_first_of(d), Piece::npos);
    ASSERT_EQ(a.find_first_of(e), Piece::npos);
    ASSERT_EQ(d.find_first_of(b), Piece::npos);
    ASSERT_EQ(e.find_first_of(b), Piece::npos);
    ASSERT_EQ(d.find_first_of(d), Piece::npos);
    ASSERT_EQ(e.find_first_of(d), Piece::npos);
    ASSERT_EQ(d.find_first_of(e), Piece::npos);
    ASSERT_EQ(e.find_first_of(e), Piece::npos);
  
    ASSERT_EQ(a.find_first_not_of(b), 3U);
    ASSERT_EQ(a.find_first_not_of(c), 0U);
    ASSERT_EQ(b.find_first_not_of(a), Piece::npos);
    ASSERT_EQ(c.find_first_not_of(a), Piece::npos);
    ASSERT_EQ(f.find_first_not_of(a), 0U);
    ASSERT_EQ(a.find_first_not_of(f), 0U);
    ASSERT_EQ(a.find_first_not_of(d), 0U);
    ASSERT_EQ(a.find_first_not_of(e), 0U);
    // empty string nonsense
    ASSERT_EQ(d.find_first_not_of(a), Piece::npos);
    ASSERT_EQ(e.find_first_not_of(a), Piece::npos);
    ASSERT_EQ(d.find_first_not_of(d), Piece::npos);
    ASSERT_EQ(e.find_first_not_of(d), Piece::npos);
    ASSERT_EQ(d.find_first_not_of(e), Piece::npos);
    ASSERT_EQ(e.find_first_not_of(e), Piece::npos);
  
    TypeParam equals(TestFixture::as_string("===="));
    Piece h(equals);
    ASSERT_EQ(h.find_first_not_of('='), Piece::npos);
    ASSERT_EQ(h.find_first_not_of('=', 3), Piece::npos);
    ASSERT_EQ(h.find_first_not_of('\0'), 0U);
    ASSERT_EQ(g.find_first_not_of('x'), 2U);
    ASSERT_EQ(f.find_first_not_of('\0'), 0U);
    ASSERT_EQ(f.find_first_not_of('\0', 3), 4U);
    ASSERT_EQ(f.find_first_not_of('\0', 2), 2U);
    // empty string nonsense
    ASSERT_EQ(d.find_first_not_of('x'), Piece::npos);
    ASSERT_EQ(e.find_first_not_of('x'), Piece::npos);
    ASSERT_EQ(d.find_first_not_of('\0'), Piece::npos);
    ASSERT_EQ(e.find_first_not_of('\0'), Piece::npos);
  
    //  Piece g("xx not found bb");
    TypeParam fifty_six(TestFixture::as_string("56"));
    Piece i(fifty_six);
    ASSERT_EQ(h.find_last_of(a), Piece::npos);
    ASSERT_EQ(g.find_last_of(a), g.size()-1);
    ASSERT_EQ(a.find_last_of(b), 2U);
    ASSERT_EQ(a.find_last_of(c), a.size()-1);
    ASSERT_EQ(f.find_last_of(i), 6U);
    ASSERT_EQ(a.find_last_of('a'), 0U);
    ASSERT_EQ(a.find_last_of('b'), 1U);
    ASSERT_EQ(a.find_last_of('z'), 25U);
    ASSERT_EQ(a.find_last_of('a', 5), 0U);
    ASSERT_EQ(a.find_last_of('b', 5), 1U);
    ASSERT_EQ(a.find_last_of('b', 0), Piece::npos);
    ASSERT_EQ(a.find_last_of('z', 25), 25U);
    ASSERT_EQ(a.find_last_of('z', 24), Piece::npos);
    ASSERT_EQ(f.find_last_of(i, 5), 5U);
    ASSERT_EQ(f.find_last_of(i, 6), 6U);
    ASSERT_EQ(f.find_last_of(a, 4), Piece::npos);
    // empty string nonsense
    ASSERT_EQ(f.find_last_of(d), Piece::npos);
    ASSERT_EQ(f.find_last_of(e), Piece::npos);
    ASSERT_EQ(f.find_last_of(d, 4), Piece::npos);
    ASSERT_EQ(f.find_last_of(e, 4), Piece::npos);
    ASSERT_EQ(d.find_last_of(d), Piece::npos);
    ASSERT_EQ(d.find_last_of(e), Piece::npos);
    ASSERT_EQ(e.find_last_of(d), Piece::npos);
    ASSERT_EQ(e.find_last_of(e), Piece::npos);
    ASSERT_EQ(d.find_last_of(f), Piece::npos);
    ASSERT_EQ(e.find_last_of(f), Piece::npos);
    ASSERT_EQ(d.find_last_of(d, 4), Piece::npos);
    ASSERT_EQ(d.find_last_of(e, 4), Piece::npos);
    ASSERT_EQ(e.find_last_of(d, 4), Piece::npos);
    ASSERT_EQ(e.find_last_of(e, 4), Piece::npos);
    ASSERT_EQ(d.find_last_of(f, 4), Piece::npos);
    ASSERT_EQ(e.find_last_of(f, 4), Piece::npos);
  
    ASSERT_EQ(a.find_last_not_of(b), a.size()-1);
    ASSERT_EQ(a.find_last_not_of(c), 22U);
    ASSERT_EQ(b.find_last_not_of(a), Piece::npos);
    ASSERT_EQ(b.find_last_not_of(b), Piece::npos);
    ASSERT_EQ(f.find_last_not_of(i), 4U);
    ASSERT_EQ(a.find_last_not_of(c, 24), 22U);
    ASSERT_EQ(a.find_last_not_of(b, 3), 3U);
    ASSERT_EQ(a.find_last_not_of(b, 2), Piece::npos);
    // empty string nonsense
    ASSERT_EQ(f.find_last_not_of(d), f.size()-1);
    ASSERT_EQ(f.find_last_not_of(e), f.size()-1);
    ASSERT_EQ(f.find_last_not_of(d, 4), 4U);
    ASSERT_EQ(f.find_last_not_of(e, 4), 4U);
    ASSERT_EQ(d.find_last_not_of(d), Piece::npos);
    ASSERT_EQ(d.find_last_not_of(e), Piece::npos);
    ASSERT_EQ(e.find_last_not_of(d), Piece::npos);
    ASSERT_EQ(e.find_last_not_of(e), Piece::npos);
    ASSERT_EQ(d.find_last_not_of(f), Piece::npos);
    ASSERT_EQ(e.find_last_not_of(f), Piece::npos);
    ASSERT_EQ(d.find_last_not_of(d, 4), Piece::npos);
    ASSERT_EQ(d.find_last_not_of(e, 4), Piece::npos);
    ASSERT_EQ(e.find_last_not_of(d, 4), Piece::npos);
    ASSERT_EQ(e.find_last_not_of(e, 4), Piece::npos);
    ASSERT_EQ(d.find_last_not_of(f, 4), Piece::npos);
    ASSERT_EQ(e.find_last_not_of(f, 4), Piece::npos);
  
    ASSERT_EQ(h.find_last_not_of('x'), h.size() - 1);
    ASSERT_EQ(h.find_last_not_of('='), Piece::npos);
    ASSERT_EQ(b.find_last_not_of('c'), 1U);
    ASSERT_EQ(h.find_last_not_of('x', 2), 2U);
    ASSERT_EQ(h.find_last_not_of('=', 2), Piece::npos);
    ASSERT_EQ(b.find_last_not_of('b', 1), 0U);
    // empty string nonsense
    ASSERT_EQ(d.find_last_not_of('x'), Piece::npos);
    ASSERT_EQ(e.find_last_not_of('x'), Piece::npos);
    ASSERT_EQ(d.find_last_not_of('\0'), Piece::npos);
    ASSERT_EQ(e.find_last_not_of('\0'), Piece::npos);
  
    ASSERT_EQ(a.substr(0, 3), b);
    ASSERT_EQ(a.substr(23), c);
    ASSERT_EQ(a.substr(23, 3), c);
    ASSERT_EQ(a.substr(23, 99), c);
    ASSERT_EQ(a.substr(0), a);
    ASSERT_EQ(a.substr(3, 2), TestFixture::as_string("de"));
    // empty string nonsense
    ASSERT_EQ(a.substr(99, 2), e);
    ASSERT_EQ(d.substr(99), e);
    ASSERT_EQ(d.substr(0, 99), e);
    ASSERT_EQ(d.substr(99, 99), e);
  }
  
  TYPED_TEST(CommonStringPieceTest, CheckCustom) {
    TypeParam foobar(TestFixture::as_string("foobar"));
    BasicStringPiece<TypeParam> a(foobar);
    TypeParam s1(TestFixture::as_string("123"));
    s1 += static_cast<typename TypeParam::value_type>('\0');
    s1 += TestFixture::as_string("456");
    BasicStringPiece<TypeParam> b(s1);
    BasicStringPiece<TypeParam> e;
    TypeParam s2;
  
    // remove_prefix
    BasicStringPiece<TypeParam> c(a);
    c.remove_prefix(3);
    ASSERT_EQ(c, TestFixture::as_string("bar"));
    c = a;
    c.remove_prefix(0);
    ASSERT_EQ(c, a);
    c.remove_prefix(c.size());
    ASSERT_EQ(c, e);
  
    // remove_suffix
    c = a;
    c.remove_suffix(3);
    ASSERT_EQ(c, TestFixture::as_string("foo"));
    c = a;
    c.remove_suffix(0);
    ASSERT_EQ(c, a);
    c.remove_suffix(c.size());
    ASSERT_EQ(c, e);
  
    // set
    c.set(foobar.c_str());
    ASSERT_EQ(c, a);
    c.set(foobar.c_str(), 6);
    ASSERT_EQ(c, a);
    c.set(foobar.c_str(), 0);
    ASSERT_EQ(c, e);
    c.set(foobar.c_str(), 7);  // Note, has an embedded NULL
    ASSERT_NE(c, a);
  
    // as_string
    TypeParam s3(a.as_string().c_str(), 7);  // Note, has an embedded NULL
    ASSERT_TRUE(c == s3);
    TypeParam s4(e.as_string());
    ASSERT_TRUE(s4.empty());
  }
  
  TEST(StringPieceTest, CheckCustom) {
    StringPiece a("foobar");
    std::string s1("123");
    s1 += '\0';
    s1 += "456";
    StringPiece b(s1);
    StringPiece e;
    std::string s2;
  
    // CopyToString
    a.CopyToString(&s2);
    ASSERT_EQ(s2.size(), 6U);
    ASSERT_EQ(s2, "foobar");
    b.CopyToString(&s2);
    ASSERT_EQ(s2.size(), 7U);
    ASSERT_EQ(s1, s2);
    e.CopyToString(&s2);
    ASSERT_TRUE(s2.empty());
  
    // AppendToString
    s2.erase();
    a.AppendToString(&s2);
    ASSERT_EQ(s2.size(), 6U);
    ASSERT_EQ(s2, "foobar");
    a.AppendToString(&s2);
    ASSERT_EQ(s2.size(), 12U);
    ASSERT_EQ(s2, "foobarfoobar");
  
    // starts_with
    ASSERT_TRUE(a.starts_with(a));
    ASSERT_TRUE(a.starts_with("foo"));
    ASSERT_TRUE(a.starts_with(e));
    ASSERT_TRUE(b.starts_with(s1));
    ASSERT_TRUE(b.starts_with(b));
    ASSERT_TRUE(b.starts_with(e));
    ASSERT_TRUE(e.starts_with(""));
    ASSERT_TRUE(!a.starts_with(b));
    ASSERT_TRUE(!b.starts_with(a));
    ASSERT_TRUE(!e.starts_with(a));
  
    // ends with
    ASSERT_TRUE(a.ends_with(a));
    ASSERT_TRUE(a.ends_with("bar"));
    ASSERT_TRUE(a.ends_with(e));
    ASSERT_TRUE(b.ends_with(s1));
    ASSERT_TRUE(b.ends_with(b));
    ASSERT_TRUE(b.ends_with(e));
    ASSERT_TRUE(e.ends_with(""));
    ASSERT_TRUE(!a.ends_with(b));
    ASSERT_TRUE(!b.ends_with(a));
    ASSERT_TRUE(!e.ends_with(a));
  
    StringPiece c;
    c.set("foobar", 6);
    ASSERT_EQ(c, a);
    c.set("foobar", 0);
    ASSERT_EQ(c, e);
    c.set("foobar", 7);
    ASSERT_NE(c, a);
  }
  
  TYPED_TEST(CommonStringPieceTest, CheckNULL) {
    // we used to crash here, but now we don't.
    BasicStringPiece<TypeParam> s(NULL);
    ASSERT_EQ(s.data(), (const typename TypeParam::value_type*)NULL);
    ASSERT_EQ(s.size(), 0U);
  
    s.set(NULL);
    ASSERT_EQ(s.data(), (const typename TypeParam::value_type*)NULL);
    ASSERT_EQ(s.size(), 0U);
  
    TypeParam str = s.as_string();
    ASSERT_EQ(str.length(), 0U);
    ASSERT_EQ(str, TypeParam());
  }
  
  TYPED_TEST(CommonStringPieceTest, CheckComparisons2) {
    TypeParam alphabet(TestFixture::as_string("abcdefghijklmnopqrstuvwxyz"));
    TypeParam alphabet_z(TestFixture::as_string("abcdefghijklmnopqrstuvwxyzz"));
    TypeParam alphabet_y(TestFixture::as_string("abcdefghijklmnopqrstuvwxyy"));
    BasicStringPiece<TypeParam> abc(alphabet);
  
    // check comparison operations on strings longer than 4 bytes.
    ASSERT_TRUE(abc == BasicStringPiece<TypeParam>(alphabet));
    ASSERT_TRUE(abc.compare(BasicStringPiece<TypeParam>(alphabet)) == 0);
  
    ASSERT_TRUE(abc < BasicStringPiece<TypeParam>(alphabet_z));
    ASSERT_TRUE(abc.compare(BasicStringPiece<TypeParam>(alphabet_z)) < 0);
  
    ASSERT_TRUE(abc > BasicStringPiece<TypeParam>(alphabet_y));
    ASSERT_TRUE(abc.compare(BasicStringPiece<TypeParam>(alphabet_y)) > 0);
  }
  
  // Test operations only supported by std::string version.
  TEST(StringPieceTest, CheckComparisons2) {
    StringPiece abc("abcdefghijklmnopqrstuvwxyz");
  
    // starts_with
    ASSERT_TRUE(abc.starts_with(abc));
    ASSERT_TRUE(abc.starts_with("abcdefghijklm"));
    ASSERT_TRUE(!abc.starts_with("abcdefguvwxyz"));
  
    // ends_with
    ASSERT_TRUE(abc.ends_with(abc));
    ASSERT_TRUE(!abc.ends_with("abcdefguvwxyz"));
    ASSERT_TRUE(abc.ends_with("nopqrstuvwxyz"));
  }
  
  TYPED_TEST(CommonStringPieceTest, StringCompareNotAmbiguous) {
    ASSERT_TRUE(TestFixture::as_string("hello").c_str() ==
                TestFixture::as_string("hello"));
    ASSERT_TRUE(TestFixture::as_string("hello").c_str() <
                TestFixture::as_string("world"));
  }
  
  TYPED_TEST(CommonStringPieceTest, HeterogenousStringPieceEquals) {
    TypeParam hello(TestFixture::as_string("hello"));
  
    ASSERT_TRUE(BasicStringPiece<TypeParam>(hello) == hello);
    ASSERT_TRUE(hello.c_str() == BasicStringPiece<TypeParam>(hello));
  }
  
  // string16-specific stuff
  TEST(StringPiece16Test, CheckSTL) {
    // Check some non-ascii characters.
    string16 fifth(ASCIIToUTF16("123"));
    fifth.push_back(0x0000);
    fifth.push_back(0xd8c5);
    fifth.push_back(0xdffe);
    StringPiece16 f(fifth);
  
    ASSERT_EQ(f[3], '\0');
    ASSERT_EQ(f[5], static_cast<char16>(0xdffe));
  
    ASSERT_EQ(f.size(), 6U);
  }
  
  
  
  TEST(StringPiece16Test, CheckConversion) {
    // Make sure that we can convert from UTF8 to UTF16 and back. We use a two
    // byte character (G clef) to test this.
    ASSERT_EQ(
        UTF16ToUTF8(
            StringPiece16(UTF8ToUTF16("\xf0\x9d\x84\x9e")).as_string()),
        "\xf0\x9d\x84\x9e");
  }
  
  TYPED_TEST(CommonStringPieceTest, CheckConstructors) {
    TypeParam str(TestFixture::as_string("hello world"));
    TypeParam empty;
  
    ASSERT_TRUE(str == BasicStringPiece<TypeParam>(str));
    ASSERT_TRUE(str == BasicStringPiece<TypeParam>(str.c_str()));
    ASSERT_TRUE(TestFixture::as_string("hello") ==
                BasicStringPiece<TypeParam>(str.c_str(), 5));
    ASSERT_TRUE(empty == BasicStringPiece<TypeParam>(str.c_str(), 0U));
    ASSERT_TRUE(empty == BasicStringPiece<TypeParam>(NULL));
    ASSERT_TRUE(empty == BasicStringPiece<TypeParam>(NULL, 0U));
    ASSERT_TRUE(empty == BasicStringPiece<TypeParam>());
    ASSERT_TRUE(str == BasicStringPiece<TypeParam>(str.begin(), str.end()));
    ASSERT_TRUE(empty == BasicStringPiece<TypeParam>(str.begin(), str.begin()));
    ASSERT_TRUE(empty == BasicStringPiece<TypeParam>(empty));
    ASSERT_TRUE(empty == BasicStringPiece<TypeParam>(empty.begin(), empty.end()));
  }
  
  }  // namespace base
  