// Copyright 2014 PDFium 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 "core/fxcrt/cfx_bytestring.h"
#include "core/fxcrt/fx_string.h"

#include <algorithm>
#include <vector>

#include "testing/gtest/include/gtest/gtest.h"
#include "third_party/base/stl_util.h"

TEST(fxcrt, ByteStringElementAccess) {
  const CFX_ByteString abc("abc");
#ifndef NDEBUG
  EXPECT_DEATH({ abc[-1]; }, ".*");
#endif
  EXPECT_EQ('a', abc[0]);
  EXPECT_EQ('b', abc[1]);
  EXPECT_EQ('c', abc[2]);
#ifndef NDEBUG
  EXPECT_DEATH({ abc[3]; }, ".*");
#endif

  CFX_ByteString mutable_abc = abc;
  EXPECT_EQ(abc.c_str(), mutable_abc.c_str());
  EXPECT_EQ('a', mutable_abc[0]);
  EXPECT_EQ('b', mutable_abc[1]);
  EXPECT_EQ('c', mutable_abc[2]);
  EXPECT_EQ(abc.c_str(), mutable_abc.c_str());

#ifndef NDEBUG
  EXPECT_DEATH({ mutable_abc.SetAt(-1, 'd'); }, ".*");
  EXPECT_EQ("abc", abc);
#endif
  const char* c_str = abc.c_str();
  mutable_abc.SetAt(0, 'd');
  EXPECT_EQ(c_str, abc.c_str());
  EXPECT_NE(c_str, mutable_abc.c_str());
  EXPECT_EQ("abc", abc);
  EXPECT_EQ("dbc", mutable_abc);

  mutable_abc.SetAt(1, 'e');
  EXPECT_EQ("abc", abc);
  EXPECT_EQ("dec", mutable_abc);

  mutable_abc.SetAt(2, 'f');
  EXPECT_EQ("abc", abc);
  EXPECT_EQ("def", mutable_abc);
#ifndef NDEBUG
  EXPECT_DEATH({ mutable_abc.SetAt(3, 'g'); }, ".*");
  EXPECT_EQ("abc", abc);
#endif
}

TEST(fxcrt, ByteStringOperatorLT) {
  CFX_ByteString empty;
  CFX_ByteString a("a");
  CFX_ByteString abc("abc");
  CFX_ByteString def("def");

  EXPECT_FALSE(empty < empty);
  EXPECT_FALSE(a < a);
  EXPECT_FALSE(abc < abc);
  EXPECT_FALSE(def < def);

  EXPECT_TRUE(empty < a);
  EXPECT_FALSE(a < empty);

  EXPECT_TRUE(empty < abc);
  EXPECT_FALSE(abc < empty);

  EXPECT_TRUE(empty < def);
  EXPECT_FALSE(def < empty);

  EXPECT_TRUE(a < abc);
  EXPECT_FALSE(abc < a);

  EXPECT_TRUE(a < def);
  EXPECT_FALSE(def < a);

  EXPECT_TRUE(abc < def);
  EXPECT_FALSE(def < abc);
}

TEST(fxcrt, ByteStringOperatorEQ) {
  CFX_ByteString null_string;
  EXPECT_TRUE(null_string == null_string);

  CFX_ByteString empty_string("");
  EXPECT_TRUE(empty_string == empty_string);
  EXPECT_TRUE(empty_string == null_string);
  EXPECT_TRUE(null_string == empty_string);

  CFX_ByteString deleted_string("hello");
  deleted_string.Delete(0, 5);
  EXPECT_TRUE(deleted_string == deleted_string);
  EXPECT_TRUE(deleted_string == null_string);
  EXPECT_TRUE(deleted_string == empty_string);
  EXPECT_TRUE(null_string == deleted_string);
  EXPECT_TRUE(empty_string == deleted_string);

  CFX_ByteString byte_string("hello");
  EXPECT_TRUE(byte_string == byte_string);
  EXPECT_FALSE(byte_string == null_string);
  EXPECT_FALSE(byte_string == empty_string);
  EXPECT_FALSE(byte_string == deleted_string);
  EXPECT_FALSE(null_string == byte_string);
  EXPECT_FALSE(empty_string == byte_string);
  EXPECT_FALSE(deleted_string == byte_string);

  CFX_ByteString byte_string_same1("hello");
  EXPECT_TRUE(byte_string == byte_string_same1);
  EXPECT_TRUE(byte_string_same1 == byte_string);

  CFX_ByteString byte_string_same2(byte_string);
  EXPECT_TRUE(byte_string == byte_string_same2);
  EXPECT_TRUE(byte_string_same2 == byte_string);

  CFX_ByteString byte_string1("he");
  CFX_ByteString byte_string2("hellp");
  CFX_ByteString byte_string3("hellod");
  EXPECT_FALSE(byte_string == byte_string1);
  EXPECT_FALSE(byte_string == byte_string2);
  EXPECT_FALSE(byte_string == byte_string3);
  EXPECT_FALSE(byte_string1 == byte_string);
  EXPECT_FALSE(byte_string2 == byte_string);
  EXPECT_FALSE(byte_string3 == byte_string);

  CFX_ByteStringC null_string_c;
  CFX_ByteStringC empty_string_c("");
  EXPECT_TRUE(null_string == null_string_c);
  EXPECT_TRUE(null_string == empty_string_c);
  EXPECT_TRUE(empty_string == null_string_c);
  EXPECT_TRUE(empty_string == empty_string_c);
  EXPECT_TRUE(deleted_string == null_string_c);
  EXPECT_TRUE(deleted_string == empty_string_c);
  EXPECT_TRUE(null_string_c == null_string);
  EXPECT_TRUE(empty_string_c == null_string);
  EXPECT_TRUE(null_string_c == empty_string);
  EXPECT_TRUE(empty_string_c == empty_string);
  EXPECT_TRUE(null_string_c == deleted_string);
  EXPECT_TRUE(empty_string_c == deleted_string);

  CFX_ByteStringC byte_string_c_same1("hello");
  EXPECT_TRUE(byte_string == byte_string_c_same1);
  EXPECT_TRUE(byte_string_c_same1 == byte_string);

  CFX_ByteStringC byte_string_c1("he");
  CFX_ByteStringC byte_string_c2("hellp");
  CFX_ByteStringC byte_string_c3("hellod");
  EXPECT_FALSE(byte_string == byte_string_c1);
  EXPECT_FALSE(byte_string == byte_string_c2);
  EXPECT_FALSE(byte_string == byte_string_c3);
  EXPECT_FALSE(byte_string_c1 == byte_string);
  EXPECT_FALSE(byte_string_c2 == byte_string);
  EXPECT_FALSE(byte_string_c3 == byte_string);

  const char* c_null_string = nullptr;
  const char* c_empty_string = "";
  EXPECT_TRUE(null_string == c_null_string);
  EXPECT_TRUE(null_string == c_empty_string);
  EXPECT_TRUE(empty_string == c_null_string);
  EXPECT_TRUE(empty_string == c_empty_string);
  EXPECT_TRUE(deleted_string == c_null_string);
  EXPECT_TRUE(deleted_string == c_empty_string);
  EXPECT_TRUE(c_null_string == null_string);
  EXPECT_TRUE(c_empty_string == null_string);
  EXPECT_TRUE(c_null_string == empty_string);
  EXPECT_TRUE(c_empty_string == empty_string);
  EXPECT_TRUE(c_null_string == deleted_string);
  EXPECT_TRUE(c_empty_string == deleted_string);

  const char* c_string_same1 = "hello";
  EXPECT_TRUE(byte_string == c_string_same1);
  EXPECT_TRUE(c_string_same1 == byte_string);

  const char* c_string1 = "he";
  const char* c_string2 = "hellp";
  const char* c_string3 = "hellod";
  EXPECT_FALSE(byte_string == c_string1);
  EXPECT_FALSE(byte_string == c_string2);
  EXPECT_FALSE(byte_string == c_string3);
  EXPECT_FALSE(c_string1 == byte_string);
  EXPECT_FALSE(c_string2 == byte_string);
  EXPECT_FALSE(c_string3 == byte_string);
}

TEST(fxcrt, ByteStringOperatorNE) {
  CFX_ByteString null_string;
  EXPECT_FALSE(null_string != null_string);

  CFX_ByteString empty_string("");
  EXPECT_FALSE(empty_string != empty_string);
  EXPECT_FALSE(empty_string != null_string);
  EXPECT_FALSE(null_string != empty_string);

  CFX_ByteString deleted_string("hello");
  deleted_string.Delete(0, 5);
  EXPECT_FALSE(deleted_string != deleted_string);
  EXPECT_FALSE(deleted_string != null_string);
  EXPECT_FALSE(deleted_string != empty_string);
  EXPECT_FALSE(deleted_string != deleted_string);
  EXPECT_FALSE(null_string != deleted_string);
  EXPECT_FALSE(empty_string != deleted_string);
  EXPECT_FALSE(deleted_string != deleted_string);

  CFX_ByteString byte_string("hello");
  EXPECT_FALSE(byte_string != byte_string);
  EXPECT_TRUE(byte_string != null_string);
  EXPECT_TRUE(byte_string != empty_string);
  EXPECT_TRUE(byte_string != deleted_string);
  EXPECT_TRUE(null_string != byte_string);
  EXPECT_TRUE(empty_string != byte_string);
  EXPECT_TRUE(deleted_string != byte_string);

  CFX_ByteString byte_string_same1("hello");
  EXPECT_FALSE(byte_string != byte_string_same1);
  EXPECT_FALSE(byte_string_same1 != byte_string);

  CFX_ByteString byte_string_same2(byte_string);
  EXPECT_FALSE(byte_string != byte_string_same2);
  EXPECT_FALSE(byte_string_same2 != byte_string);

  CFX_ByteString byte_string1("he");
  CFX_ByteString byte_string2("hellp");
  CFX_ByteString byte_string3("hellod");
  EXPECT_TRUE(byte_string != byte_string1);
  EXPECT_TRUE(byte_string != byte_string2);
  EXPECT_TRUE(byte_string != byte_string3);
  EXPECT_TRUE(byte_string1 != byte_string);
  EXPECT_TRUE(byte_string2 != byte_string);
  EXPECT_TRUE(byte_string3 != byte_string);

  CFX_ByteStringC null_string_c;
  CFX_ByteStringC empty_string_c("");
  EXPECT_FALSE(null_string != null_string_c);
  EXPECT_FALSE(null_string != empty_string_c);
  EXPECT_FALSE(empty_string != null_string_c);
  EXPECT_FALSE(empty_string != empty_string_c);
  EXPECT_FALSE(null_string_c != null_string);
  EXPECT_FALSE(empty_string_c != null_string);
  EXPECT_FALSE(null_string_c != empty_string);
  EXPECT_FALSE(empty_string_c != empty_string);

  CFX_ByteStringC byte_string_c_same1("hello");
  EXPECT_FALSE(byte_string != byte_string_c_same1);
  EXPECT_FALSE(byte_string_c_same1 != byte_string);

  CFX_ByteStringC byte_string_c1("he");
  CFX_ByteStringC byte_string_c2("hellp");
  CFX_ByteStringC byte_string_c3("hellod");
  EXPECT_TRUE(byte_string != byte_string_c1);
  EXPECT_TRUE(byte_string != byte_string_c2);
  EXPECT_TRUE(byte_string != byte_string_c3);
  EXPECT_TRUE(byte_string_c1 != byte_string);
  EXPECT_TRUE(byte_string_c2 != byte_string);
  EXPECT_TRUE(byte_string_c3 != byte_string);

  const char* c_null_string = nullptr;
  const char* c_empty_string = "";
  EXPECT_FALSE(null_string != c_null_string);
  EXPECT_FALSE(null_string != c_empty_string);
  EXPECT_FALSE(empty_string != c_null_string);
  EXPECT_FALSE(empty_string != c_empty_string);
  EXPECT_FALSE(deleted_string != c_null_string);
  EXPECT_FALSE(deleted_string != c_empty_string);
  EXPECT_FALSE(c_null_string != null_string);
  EXPECT_FALSE(c_empty_string != null_string);
  EXPECT_FALSE(c_null_string != empty_string);
  EXPECT_FALSE(c_empty_string != empty_string);
  EXPECT_FALSE(c_null_string != deleted_string);
  EXPECT_FALSE(c_empty_string != deleted_string);

  const char* c_string_same1 = "hello";
  EXPECT_FALSE(byte_string != c_string_same1);
  EXPECT_FALSE(c_string_same1 != byte_string);

  const char* c_string1 = "he";
  const char* c_string2 = "hellp";
  const char* c_string3 = "hellod";
  EXPECT_TRUE(byte_string != c_string1);
  EXPECT_TRUE(byte_string != c_string2);
  EXPECT_TRUE(byte_string != c_string3);
  EXPECT_TRUE(c_string1 != byte_string);
  EXPECT_TRUE(c_string2 != byte_string);
  EXPECT_TRUE(c_string3 != byte_string);
}

TEST(fxcrt, ByteStringCNull) {
  CFX_ByteStringC null_string;
  EXPECT_FALSE(null_string.raw_str());
  EXPECT_EQ(0u, null_string.GetLength());
  EXPECT_TRUE(null_string.IsEmpty());

  CFX_ByteStringC another_null_string;
  EXPECT_EQ(null_string, another_null_string);

  CFX_ByteStringC copied_null_string(null_string);
  EXPECT_FALSE(copied_null_string.raw_str());
  EXPECT_EQ(0u, copied_null_string.GetLength());
  EXPECT_TRUE(copied_null_string.IsEmpty());
  EXPECT_EQ(null_string, copied_null_string);

  CFX_ByteStringC empty_string("");  // Pointer to NUL, not NULL pointer.
  EXPECT_TRUE(empty_string.raw_str());
  EXPECT_EQ(0u, empty_string.GetLength());
  EXPECT_TRUE(empty_string.IsEmpty());
  EXPECT_EQ(null_string, empty_string);

  CFX_ByteStringC assigned_null_string("initially not nullptr");
  assigned_null_string = null_string;
  EXPECT_FALSE(assigned_null_string.raw_str());
  EXPECT_EQ(0u, assigned_null_string.GetLength());
  EXPECT_TRUE(assigned_null_string.IsEmpty());
  EXPECT_EQ(null_string, assigned_null_string);

  CFX_ByteStringC assigned_nullptr_string("initially not nullptr");
  assigned_nullptr_string = nullptr;
  EXPECT_FALSE(assigned_nullptr_string.raw_str());
  EXPECT_EQ(0u, assigned_nullptr_string.GetLength());
  EXPECT_TRUE(assigned_nullptr_string.IsEmpty());
  EXPECT_EQ(null_string, assigned_nullptr_string);

  CFX_ByteStringC non_null_string("a");
  EXPECT_NE(null_string, non_null_string);
}

TEST(fxcrt, ByteStringConcat) {
  CFX_ByteString fred;
  fred.Concat("FRED", 4);
  EXPECT_EQ("FRED", fred);

  fred.Concat("DY", 2);
  EXPECT_EQ("FREDDY", fred);

  fred.Delete(3, 3);
  EXPECT_EQ("FRE", fred);

  fred.Concat("D", 1);
  EXPECT_EQ("FRED", fred);

  CFX_ByteString copy = fred;
  fred.Concat("DY", 2);
  EXPECT_EQ("FREDDY", fred);
  EXPECT_EQ("FRED", copy);
}

TEST(fxcrt, ByteStringRemove) {
  CFX_ByteString freed("FREED");
  freed.Remove('E');
  EXPECT_EQ("FRD", freed);
  freed.Remove('F');
  EXPECT_EQ("RD", freed);
  freed.Remove('D');
  EXPECT_EQ("R", freed);
  freed.Remove('X');
  EXPECT_EQ("R", freed);
  freed.Remove('R');
  EXPECT_EQ("", freed);

  CFX_ByteString empty;
  empty.Remove('X');
  EXPECT_EQ("", empty);
}

TEST(fxcrt, ByteStringRemoveCopies) {
  CFX_ByteString freed("FREED");
  const char* old_buffer = freed.c_str();

  // No change with single reference - no copy.
  freed.Remove('Q');
  EXPECT_EQ("FREED", freed);
  EXPECT_EQ(old_buffer, freed.c_str());

  // Change with single reference - no copy.
  freed.Remove('E');
  EXPECT_EQ("FRD", freed);
  EXPECT_EQ(old_buffer, freed.c_str());

  // No change with multiple references - no copy.
  CFX_ByteString shared(freed);
  freed.Remove('Q');
  EXPECT_EQ("FRD", freed);
  EXPECT_EQ(old_buffer, freed.c_str());
  EXPECT_EQ(old_buffer, shared.c_str());

  // Change with multiple references -- must copy.
  freed.Remove('D');
  EXPECT_EQ("FR", freed);
  EXPECT_NE(old_buffer, freed.c_str());
  EXPECT_EQ("FRD", shared);
  EXPECT_EQ(old_buffer, shared.c_str());
}

TEST(fxcrt, ByteStringReplace) {
  CFX_ByteString fred("FRED");
  fred.Replace("FR", "BL");
  EXPECT_EQ("BLED", fred);
  fred.Replace("D", "DDY");
  EXPECT_EQ("BLEDDY", fred);
  fred.Replace("LEDD", "");
  EXPECT_EQ("BY", fred);
  fred.Replace("X", "CLAMS");
  EXPECT_EQ("BY", fred);
  fred.Replace("BY", "HI");
  EXPECT_EQ("HI", fred);
  fred.Replace("", "CLAMS");
  EXPECT_EQ("HI", fred);
  fred.Replace("HI", "");
  EXPECT_EQ("", fred);
}

TEST(fxcrt, ByteStringInsert) {
  CFX_ByteString fred("FRED");
  EXPECT_EQ(4u, fred.Insert(-1, 'X'));
  EXPECT_EQ("FRED", fred);
  EXPECT_EQ(5u, fred.Insert(0, 'S'));
  EXPECT_EQ("SFRED", fred);
  EXPECT_EQ(6u, fred.Insert(1, 'T'));
  EXPECT_EQ("STFRED", fred);
  EXPECT_EQ(7u, fred.Insert(4, 'U'));
  EXPECT_EQ("STFRUED", fred);
  EXPECT_EQ(8u, fred.Insert(7, 'V'));
  EXPECT_EQ("STFRUEDV", fred);
  EXPECT_EQ(8u, fred.Insert(12, 'P'));
  EXPECT_EQ("STFRUEDV", fred);
  {
    CFX_ByteString empty;
    EXPECT_EQ(0u, empty.Insert(-1, 'X'));
    EXPECT_NE("X", empty);
  }
  {
    CFX_ByteString empty;
    EXPECT_EQ(1u, empty.Insert(0, 'X'));
    EXPECT_EQ("X", empty);
  }
  {
    CFX_ByteString empty;
    EXPECT_EQ(0u, empty.Insert(5, 'X'));
    EXPECT_NE("X", empty);
  }
}

TEST(fxcrt, ByteStringInsertAtFrontAndInsertAtBack) {
  {
    CFX_ByteString empty;
    EXPECT_EQ(1u, empty.InsertAtFront('D'));
    EXPECT_EQ("D", empty);
    EXPECT_EQ(2u, empty.InsertAtFront('E'));
    EXPECT_EQ("ED", empty);
    EXPECT_EQ(3u, empty.InsertAtFront('R'));
    EXPECT_EQ("RED", empty);
    EXPECT_EQ(4u, empty.InsertAtFront('F'));
    EXPECT_EQ("FRED", empty);
  }
  {
    CFX_ByteString empty;
    EXPECT_EQ(1u, empty.InsertAtBack('F'));
    EXPECT_EQ("F", empty);
    EXPECT_EQ(2u, empty.InsertAtBack('R'));
    EXPECT_EQ("FR", empty);
    EXPECT_EQ(3u, empty.InsertAtBack('E'));
    EXPECT_EQ("FRE", empty);
    EXPECT_EQ(4u, empty.InsertAtBack('D'));
    EXPECT_EQ("FRED", empty);
  }
  {
    CFX_ByteString empty;
    EXPECT_EQ(1u, empty.InsertAtBack('E'));
    EXPECT_EQ("E", empty);
    EXPECT_EQ(2u, empty.InsertAtFront('R'));
    EXPECT_EQ("RE", empty);
    EXPECT_EQ(3u, empty.InsertAtBack('D'));
    EXPECT_EQ("RED", empty);
    EXPECT_EQ(4u, empty.InsertAtFront('F'));
    EXPECT_EQ("FRED", empty);
  }
}

TEST(fxcrt, ByteStringDelete) {
  CFX_ByteString fred("FRED");
  EXPECT_EQ(4u, fred.Delete(0, 0));
  EXPECT_EQ("FRED", fred);
  EXPECT_EQ(2u, fred.Delete(0, 2));
  EXPECT_EQ("ED", fred);
  EXPECT_EQ(1u, fred.Delete(1));
  EXPECT_EQ("E", fred);
  EXPECT_EQ(1u, fred.Delete(-1));
  EXPECT_EQ("E", fred);
  EXPECT_EQ(0u, fred.Delete(0));
  EXPECT_EQ("", fred);
  EXPECT_EQ(0u, fred.Delete(0));
  EXPECT_EQ("", fred);

  CFX_ByteString empty;
  EXPECT_EQ(0u, empty.Delete(0));
  EXPECT_EQ("", empty);
  EXPECT_EQ(0u, empty.Delete(-1));
  EXPECT_EQ("", empty);
  EXPECT_EQ(0u, empty.Delete(1));
  EXPECT_EQ("", empty);
}

TEST(fxcrt, ByteStringMid) {
  CFX_ByteString fred("FRED");
  EXPECT_EQ("", fred.Mid(0, 0));
  EXPECT_EQ("", fred.Mid(3, 0));
  EXPECT_EQ("FRED", fred.Mid(0, 4));
  EXPECT_EQ("RED", fred.Mid(1, 3));
  EXPECT_EQ("ED", fred.Mid(2, 2));
  EXPECT_EQ("D", fred.Mid(3, 1));
  EXPECT_EQ("F", fred.Mid(0, 1));
  EXPECT_EQ("R", fred.Mid(1, 1));
  EXPECT_EQ("E", fred.Mid(2, 1));
  EXPECT_EQ("D", fred.Mid(3, 1));
  EXPECT_EQ("FR", fred.Mid(0, 2));
  EXPECT_EQ("FRED", fred.Mid(0, 4));
  EXPECT_EQ("", fred.Mid(0, 10));

  EXPECT_EQ("", fred.Mid(-1, 2));
  EXPECT_EQ("RED", fred.Mid(1, 3));
  EXPECT_EQ("", fred.Mid(4, 1));

  CFX_ByteString empty;
  EXPECT_EQ("", empty.Mid(0, 0));
}

TEST(fxcrt, ByteStringLeft) {
  CFX_ByteString fred("FRED");
  EXPECT_EQ("", fred.Left(0));
  EXPECT_EQ("F", fred.Left(1));
  EXPECT_EQ("FR", fred.Left(2));
  EXPECT_EQ("FRE", fred.Left(3));
  EXPECT_EQ("FRED", fred.Left(4));

  EXPECT_EQ("", fred.Left(5));
  EXPECT_EQ("", fred.Left(-1));

  CFX_ByteString empty;
  EXPECT_EQ("", empty.Left(0));
  EXPECT_EQ("", empty.Left(1));
  EXPECT_EQ("", empty.Left(-1));
}

TEST(fxcrt, ByteStringRight) {
  CFX_ByteString fred("FRED");
  EXPECT_EQ("", fred.Right(0));
  EXPECT_EQ("D", fred.Right(1));
  EXPECT_EQ("ED", fred.Right(2));
  EXPECT_EQ("RED", fred.Right(3));
  EXPECT_EQ("FRED", fred.Right(4));

  EXPECT_EQ("", fred.Right(5));
  EXPECT_EQ("", fred.Right(-1));

  CFX_ByteString empty;
  EXPECT_EQ("", empty.Right(0));
  EXPECT_EQ("", empty.Right(1));
  EXPECT_EQ("", empty.Right(-1));
}

TEST(fxcrt, ByteStringFind) {
  CFX_ByteString null_string;
  EXPECT_FALSE(null_string.Find('a').has_value());
  EXPECT_FALSE(null_string.Find('\0').has_value());

  CFX_ByteString empty_string("");
  EXPECT_FALSE(empty_string.Find('a').has_value());
  EXPECT_FALSE(empty_string.Find('\0').has_value());

  pdfium::Optional<FX_STRSIZE> result;
  CFX_ByteString single_string("a");
  result = single_string.Find('a');
  ASSERT_TRUE(result.has_value());
  EXPECT_EQ(0u, result.value());
  EXPECT_FALSE(single_string.Find('b').has_value());
  EXPECT_FALSE(single_string.Find('\0').has_value());

  CFX_ByteString longer_string("abccc");
  result = longer_string.Find('a');
  ASSERT_TRUE(result.has_value());
  EXPECT_EQ(0u, result.value());
  result = longer_string.Find('c');
  ASSERT_TRUE(result.has_value());
  EXPECT_EQ(2u, result.value());
  result = longer_string.Find('c', 3);
  ASSERT_TRUE(result.has_value());
  EXPECT_EQ(3u, result.value());
  EXPECT_FALSE(longer_string.Find('d').has_value());
  EXPECT_FALSE(longer_string.Find('\0').has_value());

  result = longer_string.Find("ab");
  ASSERT_TRUE(result.has_value());
  EXPECT_EQ(0u, result.value());
  result = longer_string.Find("ccc");
  ASSERT_TRUE(result.has_value());
  EXPECT_EQ(2u, result.value());
  result = longer_string.Find("cc", 3);
  ASSERT_TRUE(result.has_value());
  EXPECT_EQ(3u, result.value());
  EXPECT_FALSE(longer_string.Find("d").has_value());

  CFX_ByteString hibyte_string(
      "ab\x8c"
      "def");
  result = hibyte_string.Find('\x8c');
  ASSERT_TRUE(result.has_value());
  EXPECT_EQ(2u, result.value());
}

TEST(fxcrt, ByteStringReverseFind) {
  CFX_ByteString null_string;
  EXPECT_FALSE(null_string.ReverseFind('a').has_value());
  EXPECT_FALSE(null_string.ReverseFind('\0').has_value());

  CFX_ByteString empty_string("");
  EXPECT_FALSE(empty_string.ReverseFind('a').has_value());
  EXPECT_FALSE(empty_string.ReverseFind('\0').has_value());

  pdfium::Optional<FX_STRSIZE> result;
  CFX_ByteString single_string("a");
  result = single_string.ReverseFind('a');
  ASSERT_TRUE(result.has_value());
  EXPECT_EQ(0u, result.value());
  EXPECT_FALSE(single_string.ReverseFind('b').has_value());
  EXPECT_FALSE(single_string.ReverseFind('\0').has_value());

  CFX_ByteString longer_string("abccc");
  result = longer_string.ReverseFind('a');
  ASSERT_TRUE(result.has_value());
  EXPECT_EQ(0u, result.value());
  result = longer_string.ReverseFind('c');
  ASSERT_TRUE(result.has_value());
  EXPECT_EQ(4u, result.value());
  EXPECT_FALSE(longer_string.ReverseFind('\0').has_value());

  CFX_ByteString hibyte_string(
      "ab\x8c"
      "def");
  result = hibyte_string.ReverseFind('\x8c');
  ASSERT_TRUE(result.has_value());
  EXPECT_EQ(2u, result.value());
}

TEST(fxcrt, ByteStringUpperLower) {
  CFX_ByteString fred("F-Re.42D");
  fred.MakeLower();
  EXPECT_EQ("f-re.42d", fred);
  fred.MakeUpper();
  EXPECT_EQ("F-RE.42D", fred);

  CFX_ByteString empty;
  empty.MakeLower();
  EXPECT_EQ("", empty);
  empty.MakeUpper();
  EXPECT_EQ("", empty);
}

TEST(fxcrt, ByteStringTrimRight) {
  CFX_ByteString fred("  FRED  ");
  fred.TrimRight();
  EXPECT_EQ("  FRED", fred);
  fred.TrimRight('E');
  EXPECT_EQ("  FRED", fred);
  fred.TrimRight('D');
  EXPECT_EQ("  FRE", fred);
  fred.TrimRight("ERP");
  EXPECT_EQ("  F", fred);

  CFX_ByteString blank("   ");
  blank.TrimRight("ERP");
  EXPECT_EQ("   ", blank);
  blank.TrimRight('E');
  EXPECT_EQ("   ", blank);
  blank.TrimRight();
  EXPECT_EQ("", blank);

  CFX_ByteString empty;
  empty.TrimRight("ERP");
  EXPECT_EQ("", empty);
  empty.TrimRight('E');
  EXPECT_EQ("", empty);
  empty.TrimRight();
  EXPECT_EQ("", empty);
}

TEST(fxcrt, ByteStringTrimRightCopies) {
  {
    // With a single reference, no copy takes place.
    CFX_ByteString fred("  FRED  ");
    const char* old_buffer = fred.c_str();
    fred.TrimRight();
    EXPECT_EQ("  FRED", fred);
    EXPECT_EQ(old_buffer, fred.c_str());
  }
  {
    // With multiple references, we must copy.
    CFX_ByteString fred("  FRED  ");
    CFX_ByteString other_fred = fred;
    const char* old_buffer = fred.c_str();
    fred.TrimRight();
    EXPECT_EQ("  FRED", fred);
    EXPECT_EQ("  FRED  ", other_fred);
    EXPECT_NE(old_buffer, fred.c_str());
  }
  {
    // With multiple references, but no modifications, no copy.
    CFX_ByteString fred("FRED");
    CFX_ByteString other_fred = fred;
    const char* old_buffer = fred.c_str();
    fred.TrimRight();
    EXPECT_EQ("FRED", fred);
    EXPECT_EQ("FRED", other_fred);
    EXPECT_EQ(old_buffer, fred.c_str());
  }
}

TEST(fxcrt, ByteStringTrimLeft) {
  CFX_ByteString fred("  FRED  ");
  fred.TrimLeft();
  EXPECT_EQ("FRED  ", fred);
  fred.TrimLeft('E');
  EXPECT_EQ("FRED  ", fred);
  fred.TrimLeft('F');
  EXPECT_EQ("RED  ", fred);
  fred.TrimLeft("ERP");
  EXPECT_EQ("D  ", fred);

  CFX_ByteString blank("   ");
  blank.TrimLeft("ERP");
  EXPECT_EQ("   ", blank);
  blank.TrimLeft('E');
  EXPECT_EQ("   ", blank);
  blank.TrimLeft();
  EXPECT_EQ("", blank);

  CFX_ByteString empty;
  empty.TrimLeft("ERP");
  EXPECT_EQ("", empty);
  empty.TrimLeft('E');
  EXPECT_EQ("", empty);
  empty.TrimLeft();
  EXPECT_EQ("", empty);
}

TEST(fxcrt, ByteStringTrimLeftCopies) {
  {
    // With a single reference, no copy takes place.
    CFX_ByteString fred("  FRED  ");
    const char* old_buffer = fred.c_str();
    fred.TrimLeft();
    EXPECT_EQ("FRED  ", fred);
    EXPECT_EQ(old_buffer, fred.c_str());
  }
  {
    // With multiple references, we must copy.
    CFX_ByteString fred("  FRED  ");
    CFX_ByteString other_fred = fred;
    const char* old_buffer = fred.c_str();
    fred.TrimLeft();
    EXPECT_EQ("FRED  ", fred);
    EXPECT_EQ("  FRED  ", other_fred);
    EXPECT_NE(old_buffer, fred.c_str());
  }
  {
    // With multiple references, but no modifications, no copy.
    CFX_ByteString fred("FRED");
    CFX_ByteString other_fred = fred;
    const char* old_buffer = fred.c_str();
    fred.TrimLeft();
    EXPECT_EQ("FRED", fred);
    EXPECT_EQ("FRED", other_fred);
    EXPECT_EQ(old_buffer, fred.c_str());
  }
}

TEST(fxcrt, ByteStringReserve) {
  {
    CFX_ByteString str;
    str.Reserve(6);
    const char* old_buffer = str.c_str();
    str += "ABCDEF";
    EXPECT_EQ(old_buffer, str.c_str());
    str += "Blah Blah Blah Blah Blah Blah";
    EXPECT_NE(old_buffer, str.c_str());
  }
  {
    CFX_ByteString str("A");
    str.Reserve(6);
    const char* old_buffer = str.c_str();
    str += "BCDEF";
    EXPECT_EQ(old_buffer, str.c_str());
    str += "Blah Blah Blah Blah Blah Blah";
    EXPECT_NE(old_buffer, str.c_str());
  }
}

TEST(fxcrt, ByteStringGetBuffer) {
  {
    CFX_ByteString str;
    char* buffer = str.GetBuffer(12);
    // NOLINTNEXTLINE(runtime/printf)
    strcpy(buffer, "clams");
    str.ReleaseBuffer(str.GetStringLength());
    EXPECT_EQ("clams", str);
  }
  {
    CFX_ByteString str("cl");
    char* buffer = str.GetBuffer(12);
    // NOLINTNEXTLINE(runtime/printf)
    strcpy(buffer + 2, "ams");
    str.ReleaseBuffer(str.GetStringLength());
    EXPECT_EQ("clams", str);
  }
}

TEST(fxcrt, ByteStringReleaseBuffer) {
  {
    CFX_ByteString str;
    str.Reserve(12);
    str += "clams";
    const char* old_buffer = str.c_str();
    str.ReleaseBuffer(4);
    EXPECT_EQ(old_buffer, str.c_str());
    EXPECT_EQ("clam", str);
  }
  {
    CFX_ByteString str("c");
    str.Reserve(12);
    str += "lams";
    const char* old_buffer = str.c_str();
    str.ReleaseBuffer(4);
    EXPECT_EQ(old_buffer, str.c_str());
    EXPECT_EQ("clam", str);
  }
  {
    CFX_ByteString str;
    str.Reserve(200);
    str += "clams";
    const char* old_buffer = str.c_str();
    str.ReleaseBuffer(4);
    EXPECT_NE(old_buffer, str.c_str());
    EXPECT_EQ("clam", str);
  }
  {
    CFX_ByteString str("c");
    str.Reserve(200);
    str += "lams";
    const char* old_buffer = str.c_str();
    str.ReleaseBuffer(4);
    EXPECT_NE(old_buffer, str.c_str());
    EXPECT_EQ("clam", str);
  }
}

TEST(fxcrt, ByteStringCNotNull) {
  CFX_ByteStringC string3("abc");
  CFX_ByteStringC string6("abcdef");
  CFX_ByteStringC alternate_string3("abcdef", 3);
  CFX_ByteStringC embedded_nul_string7("abc\0def", 7);
  CFX_ByteStringC illegal_string7("abcdef", 7);

  EXPECT_EQ(3u, string3.GetLength());
  EXPECT_EQ(6u, string6.GetLength());
  EXPECT_EQ(3u, alternate_string3.GetLength());
  EXPECT_EQ(7u, embedded_nul_string7.GetLength());
  EXPECT_EQ(7u, illegal_string7.GetLength());

  EXPECT_NE(string3, string6);
  EXPECT_EQ(string3, alternate_string3);
  EXPECT_NE(string3, embedded_nul_string7);
  EXPECT_NE(string3, illegal_string7);
  EXPECT_NE(string6, alternate_string3);
  EXPECT_NE(string6, embedded_nul_string7);
  EXPECT_NE(string6, illegal_string7);
  EXPECT_NE(alternate_string3, embedded_nul_string7);
  EXPECT_NE(alternate_string3, illegal_string7);
  EXPECT_NE(embedded_nul_string7, illegal_string7);

  CFX_ByteStringC copied_string3(string3);
  CFX_ByteStringC copied_alternate_string3(alternate_string3);
  CFX_ByteStringC copied_embedded_nul_string7(embedded_nul_string7);

  EXPECT_EQ(string3, copied_string3);
  EXPECT_EQ(alternate_string3, copied_alternate_string3);
  EXPECT_EQ(embedded_nul_string7, copied_embedded_nul_string7);

  CFX_ByteStringC assigned_string3("intially something else");
  CFX_ByteStringC assigned_alternate_string3("initally something else");
  CFX_ByteStringC assigned_ptr_string3("initially something else");
  CFX_ByteStringC assigned_embedded_nul_string7("initially something else");

  assigned_string3 = string3;
  assigned_alternate_string3 = alternate_string3;
  assigned_ptr_string3 = "abc";
  assigned_embedded_nul_string7 = embedded_nul_string7;
  EXPECT_EQ(string3, assigned_string3);
  EXPECT_EQ(alternate_string3, assigned_alternate_string3);
  EXPECT_EQ(alternate_string3, assigned_ptr_string3);
  EXPECT_EQ(embedded_nul_string7, assigned_embedded_nul_string7);
}

TEST(fxcrt, ByteStringCFromChar) {
  CFX_ByteStringC null_string;
  CFX_ByteStringC lower_a_string("a");

  // Must have lvalues that outlive the corresponding ByteStringC.
  char nul = '\0';
  char lower_a = 'a';
  CFX_ByteStringC nul_string_from_char(nul);
  CFX_ByteStringC lower_a_string_from_char(lower_a);

  // Pointer to nul, not nullptr ptr, hence length 1 ...
  EXPECT_EQ(1u, nul_string_from_char.GetLength());
  EXPECT_NE(null_string, nul_string_from_char);

  EXPECT_EQ(1u, lower_a_string_from_char.GetLength());
  EXPECT_EQ(lower_a_string, lower_a_string_from_char);
  EXPECT_NE(nul_string_from_char, lower_a_string_from_char);

  CFX_ByteStringC longer_string("ab");
  EXPECT_NE(longer_string, lower_a_string_from_char);
}

TEST(fxcrt, ByteStringCFromVector) {
  std::vector<uint8_t> null_vec;
  CFX_ByteStringC null_string(null_vec);
  EXPECT_EQ(0u, null_string.GetLength());

  std::vector<uint8_t> lower_a_vec(10, static_cast<uint8_t>('a'));
  CFX_ByteStringC lower_a_string(lower_a_vec);
  EXPECT_EQ(static_cast<FX_STRSIZE>(10), lower_a_string.GetLength());
  EXPECT_EQ("aaaaaaaaaa", lower_a_string);

  std::vector<uint8_t> cleared_vec;
  cleared_vec.push_back(42);
  cleared_vec.pop_back();
  CFX_ByteStringC cleared_string(cleared_vec);
  EXPECT_EQ(0u, cleared_string.GetLength());
  EXPECT_EQ(nullptr, cleared_string.raw_str());
}

TEST(fxcrt, ByteStringCGetID) {
  CFX_ByteStringC null_string;
  EXPECT_EQ(0u, null_string.GetID());

  CFX_ByteStringC empty_string("");
  EXPECT_EQ(0u, empty_string.GetID());

  CFX_ByteStringC short_string("ab");
  EXPECT_EQ(FXBSTR_ID('a', 'b', 0, 0), short_string.GetID());

  CFX_ByteStringC longer_string("abcdef");
  EXPECT_EQ(FXBSTR_ID('a', 'b', 'c', 'd'), longer_string.GetID());
}

TEST(fxcrt, ByteStringCFind) {
  CFX_ByteStringC null_string;
  EXPECT_FALSE(null_string.Find('a').has_value());
  EXPECT_FALSE(null_string.Find('\0').has_value());

  CFX_ByteStringC empty_string("");
  EXPECT_FALSE(empty_string.Find('a').has_value());
  EXPECT_FALSE(empty_string.Find('\0').has_value());

  pdfium::Optional<FX_STRSIZE> result;
  CFX_ByteStringC single_string("a");
  result = single_string.Find('a');
  ASSERT_TRUE(result.has_value());
  EXPECT_EQ(0u, result.value());
  EXPECT_FALSE(single_string.Find('b').has_value());
  EXPECT_FALSE(single_string.Find('\0').has_value());

  CFX_ByteStringC longer_string("abccc");
  result = longer_string.Find('a');
  ASSERT_TRUE(result.has_value());
  EXPECT_EQ(0u, result.value());
  result = longer_string.Find('c');
  ASSERT_TRUE(result.has_value());
  EXPECT_EQ(2u, result.value());
  EXPECT_FALSE(longer_string.Find('d').has_value());
  EXPECT_FALSE(longer_string.Find('\0').has_value());

  CFX_ByteStringC hibyte_string(
      "ab\x8c"
      "def");
  result = hibyte_string.Find('\x8c');
  ASSERT_TRUE(result.has_value());
  EXPECT_EQ(2u, result.value());
}

TEST(fxcrt, ByteStringCMid) {
  CFX_ByteStringC null_string;
  EXPECT_EQ(null_string, null_string.Mid(0, 1));
  EXPECT_EQ(null_string, null_string.Mid(1, 1));

  CFX_ByteStringC empty_string("");
  EXPECT_EQ("", empty_string.Mid(0, 1));
  EXPECT_EQ("", empty_string.Mid(1, 1));

  CFX_ByteStringC single_character("a");
  EXPECT_EQ("", single_character.Mid(0, 0));
  EXPECT_EQ(single_character, single_character.Mid(0, 1));
  EXPECT_EQ("", single_character.Mid(1, 0));
  EXPECT_EQ("", single_character.Mid(1, 1));

  CFX_ByteStringC longer_string("abcdef");
  EXPECT_EQ(longer_string, longer_string.Mid(0, 6));
  EXPECT_EQ("", longer_string.Mid(0, 187));
  EXPECT_EQ("", longer_string.Mid(-42, 6));
  EXPECT_EQ("", longer_string.Mid(-42, 187));

  CFX_ByteStringC leading_substring("ab");
  EXPECT_EQ(leading_substring, longer_string.Mid(0, 2));
  EXPECT_EQ("", longer_string.Mid(-1, 2));

  CFX_ByteStringC middle_substring("bcde");
  EXPECT_EQ(middle_substring, longer_string.Mid(1, 4));

  CFX_ByteStringC trailing_substring("ef");
  EXPECT_EQ(trailing_substring, longer_string.Mid(4, 2));
  EXPECT_EQ("", longer_string.Mid(4, 3));
}

TEST(fxcrt, ByteStringCElementAccess) {
  // CFX_ByteStringC includes the NUL terminator for non-empty strings.
  CFX_ByteStringC abc("abc");
#ifndef NDEBUG
  EXPECT_DEATH({ abc[-1]; }, ".*");
#endif
  EXPECT_EQ('a', static_cast<char>(abc[0]));
  EXPECT_EQ('b', static_cast<char>(abc[1]));
  EXPECT_EQ('c', static_cast<char>(abc[2]));
#ifndef NDEBUG
  EXPECT_DEATH({ abc[3]; }, ".*");
#endif
}

TEST(fxcrt, ByteStringCOperatorLT) {
  CFX_ByteStringC empty;
  CFX_ByteStringC a("a");
  CFX_ByteStringC abc("abc");
  CFX_ByteStringC def("def");

  EXPECT_FALSE(empty < empty);
  EXPECT_FALSE(a < a);
  EXPECT_FALSE(abc < abc);
  EXPECT_FALSE(def < def);

  EXPECT_TRUE(empty < a);
  EXPECT_FALSE(a < empty);

  EXPECT_TRUE(empty < abc);
  EXPECT_FALSE(abc < empty);

  EXPECT_TRUE(empty < def);
  EXPECT_FALSE(def < empty);

  EXPECT_TRUE(a < abc);
  EXPECT_FALSE(abc < a);

  EXPECT_TRUE(a < def);
  EXPECT_FALSE(def < a);

  EXPECT_TRUE(abc < def);
  EXPECT_FALSE(def < abc);
}

TEST(fxcrt, ByteStringCOperatorEQ) {
  CFX_ByteStringC byte_string_c("hello");
  EXPECT_TRUE(byte_string_c == byte_string_c);

  CFX_ByteStringC byte_string_c_same1("hello");
  EXPECT_TRUE(byte_string_c == byte_string_c_same1);
  EXPECT_TRUE(byte_string_c_same1 == byte_string_c);

  CFX_ByteStringC byte_string_c_same2(byte_string_c);
  EXPECT_TRUE(byte_string_c == byte_string_c_same2);
  EXPECT_TRUE(byte_string_c_same2 == byte_string_c);

  CFX_ByteStringC byte_string_c1("he");
  CFX_ByteStringC byte_string_c2("hellp");
  CFX_ByteStringC byte_string_c3("hellod");
  EXPECT_FALSE(byte_string_c == byte_string_c1);
  EXPECT_FALSE(byte_string_c == byte_string_c2);
  EXPECT_FALSE(byte_string_c == byte_string_c3);
  EXPECT_FALSE(byte_string_c1 == byte_string_c);
  EXPECT_FALSE(byte_string_c2 == byte_string_c);
  EXPECT_FALSE(byte_string_c3 == byte_string_c);

  CFX_ByteString byte_string_same1("hello");
  EXPECT_TRUE(byte_string_c == byte_string_same1);
  EXPECT_TRUE(byte_string_same1 == byte_string_c);

  CFX_ByteString byte_string1("he");
  CFX_ByteString byte_string2("hellp");
  CFX_ByteString byte_string3("hellod");
  EXPECT_FALSE(byte_string_c == byte_string1);
  EXPECT_FALSE(byte_string_c == byte_string2);
  EXPECT_FALSE(byte_string_c == byte_string3);
  EXPECT_FALSE(byte_string1 == byte_string_c);
  EXPECT_FALSE(byte_string2 == byte_string_c);
  EXPECT_FALSE(byte_string3 == byte_string_c);

  const char* c_string_same1 = "hello";
  EXPECT_TRUE(byte_string_c == c_string_same1);
  EXPECT_TRUE(c_string_same1 == byte_string_c);

  const char* c_string1 = "he";
  const char* c_string2 = "hellp";
  const char* c_string3 = "hellod";
  EXPECT_FALSE(byte_string_c == c_string1);
  EXPECT_FALSE(byte_string_c == c_string2);
  EXPECT_FALSE(byte_string_c == c_string3);

  EXPECT_FALSE(c_string1 == byte_string_c);
  EXPECT_FALSE(c_string2 == byte_string_c);
  EXPECT_FALSE(c_string3 == byte_string_c);
}

TEST(fxcrt, ByteStringCOperatorNE) {
  CFX_ByteStringC byte_string_c("hello");
  EXPECT_FALSE(byte_string_c != byte_string_c);

  CFX_ByteStringC byte_string_c_same1("hello");
  EXPECT_FALSE(byte_string_c != byte_string_c_same1);
  EXPECT_FALSE(byte_string_c_same1 != byte_string_c);

  CFX_ByteStringC byte_string_c_same2(byte_string_c);
  EXPECT_FALSE(byte_string_c != byte_string_c_same2);
  EXPECT_FALSE(byte_string_c_same2 != byte_string_c);

  CFX_ByteStringC byte_string_c1("he");
  CFX_ByteStringC byte_string_c2("hellp");
  CFX_ByteStringC byte_string_c3("hellod");
  EXPECT_TRUE(byte_string_c != byte_string_c1);
  EXPECT_TRUE(byte_string_c != byte_string_c2);
  EXPECT_TRUE(byte_string_c != byte_string_c3);
  EXPECT_TRUE(byte_string_c1 != byte_string_c);
  EXPECT_TRUE(byte_string_c2 != byte_string_c);
  EXPECT_TRUE(byte_string_c3 != byte_string_c);

  CFX_ByteString byte_string_same1("hello");
  EXPECT_FALSE(byte_string_c != byte_string_same1);
  EXPECT_FALSE(byte_string_same1 != byte_string_c);

  CFX_ByteString byte_string1("he");
  CFX_ByteString byte_string2("hellp");
  CFX_ByteString byte_string3("hellod");
  EXPECT_TRUE(byte_string_c != byte_string1);
  EXPECT_TRUE(byte_string_c != byte_string2);
  EXPECT_TRUE(byte_string_c != byte_string3);
  EXPECT_TRUE(byte_string1 != byte_string_c);
  EXPECT_TRUE(byte_string2 != byte_string_c);
  EXPECT_TRUE(byte_string3 != byte_string_c);

  const char* c_string_same1 = "hello";
  EXPECT_FALSE(byte_string_c != c_string_same1);
  EXPECT_FALSE(c_string_same1 != byte_string_c);

  const char* c_string1 = "he";
  const char* c_string2 = "hellp";
  const char* c_string3 = "hellod";
  EXPECT_TRUE(byte_string_c != c_string1);
  EXPECT_TRUE(byte_string_c != c_string2);
  EXPECT_TRUE(byte_string_c != c_string3);

  EXPECT_TRUE(c_string1 != byte_string_c);
  EXPECT_TRUE(c_string2 != byte_string_c);
  EXPECT_TRUE(c_string3 != byte_string_c);
}

TEST(fxcrt, ByteStringCNullIterator) {
  CFX_ByteStringC null_str;
  int32_t sum = 0;
  bool any_present = false;
  for (const auto& c : null_str) {
    sum += c;  // Avoid unused arg warnings.
    any_present = true;
  }
  EXPECT_FALSE(any_present);
  EXPECT_EQ(0, sum);
}

TEST(fxcrt, ByteStringCEmptyIterator) {
  CFX_ByteStringC empty_str("");
  int32_t sum = 0;
  bool any_present = false;
  for (const auto& c : empty_str) {
    any_present = true;
    sum += c;  // Avoid unused arg warnings.
  }
  EXPECT_FALSE(any_present);
  EXPECT_EQ(0, sum);
}

TEST(fxcrt, ByteStringCOneCharIterator) {
  CFX_ByteStringC one_str("a");
  int32_t sum = 0;
  bool any_present = false;
  for (const auto& c : one_str) {
    any_present = true;
    sum += c;  // Avoid unused arg warnings.
  }
  EXPECT_TRUE(any_present);
  EXPECT_EQ('a', sum);
}

TEST(fxcrt, ByteStringCMultiCharIterator) {
  CFX_ByteStringC one_str("abc");
  int32_t sum = 0;
  bool any_present = false;
  for (const auto& c : one_str) {
    any_present = true;
    sum += c;  // Avoid unused arg warnings.
  }
  EXPECT_TRUE(any_present);
  EXPECT_EQ('a' + 'b' + 'c', sum);
}

TEST(fxcrt, ByteStringCAnyAllNoneOf) {
  CFX_ByteStringC str("aaaaaaaaaaaaaaaaab");
  EXPECT_FALSE(std::all_of(str.begin(), str.end(),
                           [](const char& c) { return c == 'a'; }));

  EXPECT_FALSE(std::none_of(str.begin(), str.end(),
                            [](const char& c) { return c == 'a'; }));

  EXPECT_TRUE(std::any_of(str.begin(), str.end(),
                          [](const char& c) { return c == 'a'; }));

  EXPECT_TRUE(pdfium::ContainsValue(str, 'a'));
  EXPECT_TRUE(pdfium::ContainsValue(str, 'b'));
  EXPECT_FALSE(pdfium::ContainsValue(str, 'z'));
}

TEST(fxcrt, ByteStringFormatWidth) {
  {
    CFX_ByteString str;
    str.Format("%5d", 1);
    EXPECT_EQ("    1", str);
  }

  {
    CFX_ByteString str;
    str.Format("%d", 1);
    EXPECT_EQ("1", str);
  }

  {
    CFX_ByteString str;
    str.Format("%*d", 5, 1);
    EXPECT_EQ("    1", str);
  }

  {
    CFX_ByteString str;
    str.Format("%-1d", 1);
    EXPECT_EQ("1", str);
  }

  {
    CFX_ByteString str;
    str.Format("%0d", 1);
    EXPECT_EQ("1", str);
  }
}

TEST(fxcrt, ByteStringFormatPrecision) {
  {
    CFX_ByteString str;
    str.Format("%.2f", 1.12345);
    EXPECT_EQ("1.12", str);
  }

  {
    CFX_ByteString str;
    str.Format("%.*f", 3, 1.12345);
    EXPECT_EQ("1.123", str);
  }

  {
    CFX_ByteString str;
    str.Format("%f", 1.12345);
    EXPECT_EQ("1.123450", str);
  }

  {
    CFX_ByteString str;
    str.Format("%-1f", 1.12345);
    EXPECT_EQ("1.123450", str);
  }

  {
    CFX_ByteString str;
    str.Format("%0f", 1.12345);
    EXPECT_EQ("1.123450", str);
  }
}

TEST(fxcrt, EmptyByteString) {
  CFX_ByteString empty_str;
  EXPECT_TRUE(empty_str.IsEmpty());
  EXPECT_EQ(0u, empty_str.GetLength());
  const char* cstr = empty_str.c_str();
  EXPECT_EQ(0u, FXSYS_strlen(cstr));
}

TEST(fxcrt, ByteStringInitializerList) {
  CFX_ByteString many_str({"clams", " and ", "oysters"});
  EXPECT_EQ("clams and oysters", many_str);
  many_str = {"fish", " and ", "chips", " and ", "soda"};
  EXPECT_EQ("fish and chips and soda", many_str);
}

TEST(fxcrt, ByteStringNullIterator) {
  CFX_ByteString null_str;
  int32_t sum = 0;
  bool any_present = false;
  for (const auto& c : null_str) {
    sum += c;  // Avoid unused arg warnings.
    any_present = true;
  }
  EXPECT_FALSE(any_present);
  EXPECT_EQ(0, sum);
}

TEST(fxcrt, ByteStringEmptyIterator) {
  CFX_ByteString empty_str("");
  int32_t sum = 0;
  bool any_present = false;
  for (const auto& c : empty_str) {
    any_present = true;
    sum += c;  // Avoid unused arg warnings.
  }
  EXPECT_FALSE(any_present);
  EXPECT_EQ(0, sum);
}

TEST(fxcrt, ByteStringOneCharIterator) {
  CFX_ByteString one_str("a");
  int32_t sum = 0;
  bool any_present = false;
  for (const auto& c : one_str) {
    any_present = true;
    sum += c;  // Avoid unused arg warnings.
  }
  EXPECT_TRUE(any_present);
  EXPECT_EQ('a', sum);
}

TEST(fxcrt, ByteStringMultiCharIterator) {
  CFX_ByteString one_str("abc");
  int32_t sum = 0;
  bool any_present = false;
  for (const auto& c : one_str) {
    any_present = true;
    sum += c;  // Avoid unused arg warnings.
  }
  EXPECT_TRUE(any_present);
  EXPECT_EQ('a' + 'b' + 'c', sum);
}

TEST(fxcrt, ByteStringAnyAllNoneOf) {
  CFX_ByteString str("aaaaaaaaaaaaaaaaab");
  EXPECT_FALSE(std::all_of(str.begin(), str.end(),
                           [](const char& c) { return c == 'a'; }));

  EXPECT_FALSE(std::none_of(str.begin(), str.end(),
                            [](const char& c) { return c == 'a'; }));

  EXPECT_TRUE(std::any_of(str.begin(), str.end(),
                          [](const char& c) { return c == 'a'; }));

  EXPECT_TRUE(pdfium::ContainsValue(str, 'a'));
  EXPECT_TRUE(pdfium::ContainsValue(str, 'b'));
  EXPECT_FALSE(pdfium::ContainsValue(str, 'z'));
}

TEST(fxcrt, EqualNoCase) {
  CFX_ByteString str("aaa");
  EXPECT_TRUE(str.EqualNoCase("aaa"));
  EXPECT_TRUE(str.EqualNoCase("AAA"));
  EXPECT_TRUE(str.EqualNoCase("aaA"));
  EXPECT_TRUE(str.EqualNoCase("Aaa"));
  EXPECT_FALSE(str.EqualNoCase("aab"));
  EXPECT_FALSE(str.EqualNoCase("aaaa"));
  EXPECT_FALSE(str.EqualNoCase("BBBB"));
  EXPECT_FALSE(str.EqualNoCase("a"));
  EXPECT_FALSE(str.EqualNoCase(""));
}

TEST(fxcrt, OStreamByteStringOverload) {
  std::ostringstream stream;

  // Basic case, empty string
  CFX_ByteString str;
  stream << str;
  EXPECT_EQ("", stream.str());

  // Basic case, non-empty string
  str = "def";
  stream.str("");
  stream << "abc" << str << "ghi";
  EXPECT_EQ("abcdefghi", stream.str());

  // Changing the CFX_ByteString does not change the stream it was written to.
  str = "123";
  EXPECT_EQ("abcdefghi", stream.str());

  // Writing it again to the stream will use the latest value.
  stream.str("");
  stream << "abc" << str << "ghi";
  EXPECT_EQ("abc123ghi", stream.str());

  char stringWithNulls[]{'x', 'y', '\0', 'z'};

  // Writing a CFX_ByteString with nulls and no specified length treats it as
  // a C-style null-terminated string.
  str = CFX_ByteString(stringWithNulls);
  EXPECT_EQ(2u, str.GetLength());
  stream.str("");
  stream << str;
  EXPECT_EQ(2u, stream.tellp());

  // Writing a CFX_ByteString with nulls but specifying its length treats it as
  // a C++-style string.
  str = CFX_ByteString(stringWithNulls, 4);
  EXPECT_EQ(4u, str.GetLength());
  stream.str("");
  stream << str;
  EXPECT_EQ(4u, stream.tellp());

  // << operators can be chained.
  CFX_ByteString str1("abc");
  CFX_ByteString str2("def");
  stream.str("");
  stream << str1 << str2;
  EXPECT_EQ("abcdef", stream.str());
}

TEST(fxcrt, OStreamByteStringCOverload) {
  // Basic case, empty string
  {
    std::ostringstream stream;
    CFX_ByteStringC str;
    stream << str;
    EXPECT_EQ("", stream.str());
  }

  // Basic case, non-empty string
  {
    std::ostringstream stream;
    CFX_ByteStringC str("def");
    stream << "abc" << str << "ghi";
    EXPECT_EQ("abcdefghi", stream.str());
  }

  // Changing the CFX_ByteStringC does not change the stream it was written to.
  {
    std::ostringstream stream;
    CFX_ByteStringC str("abc");
    stream << str;
    str = "123";
    EXPECT_EQ("abc", stream.str());
  }

  // Writing it again to the stream will use the latest value.
  {
    std::ostringstream stream;
    CFX_ByteStringC str("abc");
    stream << str;
    stream.str("");
    str = "123";
    stream << str;
    EXPECT_EQ("123", stream.str());
  }

  // Writing a CFX_ByteStringC with nulls and no specified length treats it as
  // a C-style null-terminated string.
  {
    std::ostringstream stream;
    char stringWithNulls[]{'x', 'y', '\0', 'z'};
    CFX_ByteStringC str(stringWithNulls);
    EXPECT_EQ(2u, str.GetLength());
    stream << str;
    EXPECT_EQ(2u, stream.tellp());
    str = "";
  }

  // Writing a CFX_ByteStringC with nulls but specifying its length treats it as
  // a C++-style string.
  {
    std::ostringstream stream;
    char stringWithNulls[]{'x', 'y', '\0', 'z'};
    CFX_ByteStringC str(stringWithNulls, 4);
    EXPECT_EQ(4u, str.GetLength());
    stream << str;
    EXPECT_EQ(4u, stream.tellp());
    str = "";
  }

  // << operators can be chained.
  {
    std::ostringstream stream;
    CFX_ByteStringC str1("abc");
    CFX_ByteStringC str2("def");
    stream << str1 << str2;
    EXPECT_EQ("abcdef", stream.str());
  }
}

TEST(fxcrt, ByteStringFormatInteger) {
  // Base case of 0.
  EXPECT_EQ("0", CFX_ByteString::FormatInteger(0));

  // Positive ordinary number.
  EXPECT_EQ("123456", CFX_ByteString::FormatInteger(123456));

  // Negative ordinary number.
  EXPECT_EQ("-123456", CFX_ByteString::FormatInteger(-123456));

  // int limits.
  EXPECT_EQ("2147483647", CFX_ByteString::FormatInteger(INT_MAX));
  EXPECT_EQ("-2147483648", CFX_ByteString::FormatInteger(INT_MIN));
}