fmt/test/compile-test.cc

// Formatting library for C++ - formatting library tests
//
// Copyright (c) 2012 - present, Victor Zverovich
// All rights reserved.
//
// For the license information refer to format.h.

#include <string>
#include <type_traits>
#if __cplusplus >= 202002L
#  include <string_view>
#endif

// Check that fmt/compile.h compiles with windows.h included before it.
#ifdef _WIN32
#  include <windows.h>
#endif

#include "fmt/compile.h"
#include "gmock.h"
#include "gtest-extra.h"
#include "util.h"

// compiletime_prepared_parts_type_provider is useful only with relaxed
// constexpr.
#if FMT_USE_CONSTEXPR
template <unsigned EXPECTED_PARTS_COUNT, typename Format>
void check_prepared_parts_type(Format format) {
  typedef fmt::detail::compiled_format_base<decltype(format)> provider;
  typedef fmt::detail::format_part<char>
      expected_parts_type[EXPECTED_PARTS_COUNT];
  static_assert(std::is_same<typename provider::parts_container,
                             expected_parts_type>::value,
                "CompileTimePreparedPartsTypeProvider test failed");
}

TEST(CompileTest, CompileTimePreparedPartsTypeProvider) {
  check_prepared_parts_type<1u>(FMT_STRING("text"));
  check_prepared_parts_type<1u>(FMT_STRING("{}"));
  check_prepared_parts_type<2u>(FMT_STRING("text{}"));
  check_prepared_parts_type<2u>(FMT_STRING("{}text"));
  check_prepared_parts_type<3u>(FMT_STRING("text{}text"));
  check_prepared_parts_type<3u>(FMT_STRING("{:{}.{}} {:{}}"));

  check_prepared_parts_type<3u>(FMT_STRING("{{{}}}"));   // '{', 'argument', '}'
  check_prepared_parts_type<2u>(FMT_STRING("text{{"));   // 'text', '{'
  check_prepared_parts_type<3u>(FMT_STRING("text{{ "));  // 'text', '{', ' '
  check_prepared_parts_type<2u>(FMT_STRING("}}text"));   // '}', text
  check_prepared_parts_type<2u>(FMT_STRING("text}}text"));  // 'text}', 'text'
  check_prepared_parts_type<4u>(
      FMT_STRING("text{{}}text"));  // 'text', '{', '}', 'text'
}
#endif

TEST(CompileTest, PassStringLiteralFormat) {
  const auto prepared = fmt::detail::compile<int>("test {}");
  EXPECT_EQ("test 42", fmt::format(prepared, 42));
  const auto wprepared = fmt::detail::compile<int>(L"test {}");
  EXPECT_EQ(L"test 42", fmt::format(wprepared, 42));
}

TEST(CompileTest, FormatToArrayOfChars) {
  char buffer[32] = {0};
  const auto prepared = fmt::detail::compile<int>("4{}");
  fmt::format_to(fmt::detail::make_checked(buffer, 32), prepared, 2);
  EXPECT_EQ(std::string("42"), buffer);
  wchar_t wbuffer[32] = {0};
  const auto wprepared = fmt::detail::compile<int>(L"4{}");
  fmt::format_to(fmt::detail::make_checked(wbuffer, 32), wprepared, 2);
  EXPECT_EQ(std::wstring(L"42"), wbuffer);
}

TEST(CompileTest, FormatToIterator) {
  std::string s(2, ' ');
  const auto prepared = fmt::detail::compile<int>("4{}");
  fmt::format_to(s.begin(), prepared, 2);
  EXPECT_EQ("42", s);
  std::wstring ws(2, L' ');
  const auto wprepared = fmt::detail::compile<int>(L"4{}");
  fmt::format_to(ws.begin(), wprepared, 2);
  EXPECT_EQ(L"42", ws);
}

TEST(CompileTest, FormatToN) {
  char buf[5];
  auto f = fmt::detail::compile<int>("{:10}");
  auto result = fmt::format_to_n(buf, 5, f, 42);
  EXPECT_EQ(result.size, 10);
  EXPECT_EQ(result.out, buf + 5);
  EXPECT_EQ(fmt::string_view(buf, 5), "     ");
}

TEST(CompileTest, FormattedSize) {
  auto f = fmt::detail::compile<int>("{:10}");
  EXPECT_EQ(fmt::formatted_size(f, 42), 10);
}

TEST(CompileTest, MultipleTypes) {
  auto f = fmt::detail::compile<int, int>("{} {}");
  EXPECT_EQ(fmt::format(f, 42, 42), "42 42");
}

struct test_formattable {};

FMT_BEGIN_NAMESPACE
template <> struct formatter<test_formattable> : formatter<const char*> {
  template <typename FormatContext>
  auto format(test_formattable, FormatContext& ctx) -> decltype(ctx.out()) {
    return formatter<const char*>::format("foo", ctx);
  }
};
FMT_END_NAMESPACE

TEST(CompileTest, FormatUserDefinedType) {
  auto f = fmt::detail::compile<test_formattable>("{}");
  EXPECT_EQ(fmt::format(f, test_formattable()), "foo");
}

TEST(CompileTest, EmptyFormatString) {
  auto f = fmt::detail::compile<>("");
  EXPECT_EQ(fmt::format(f), "");
}

#ifdef __cpp_if_constexpr
TEST(CompileTest, FormatDefault) {
  EXPECT_EQ("42", fmt::format(FMT_COMPILE("{}"), 42));
  EXPECT_EQ("42", fmt::format(FMT_COMPILE("{}"), 42u));
  EXPECT_EQ("42", fmt::format(FMT_COMPILE("{}"), 42ll));
  EXPECT_EQ("42", fmt::format(FMT_COMPILE("{}"), 42ull));
  EXPECT_EQ("true", fmt::format(FMT_COMPILE("{}"), true));
  EXPECT_EQ("x", fmt::format(FMT_COMPILE("{}"), 'x'));
  EXPECT_EQ("4.2", fmt::format(FMT_COMPILE("{}"), 4.2));
  EXPECT_EQ("foo", fmt::format(FMT_COMPILE("{}"), "foo"));
  EXPECT_EQ("foo", fmt::format(FMT_COMPILE("{}"), std::string("foo")));
  EXPECT_EQ("foo", fmt::format(FMT_COMPILE("{}"), test_formattable()));
}

TEST(CompileTest, FormatWideString) {
  EXPECT_EQ(L"42", fmt::format(FMT_COMPILE(L"{}"), 42));
}

TEST(CompileTest, FormatSpecs) {
  EXPECT_EQ("42", fmt::format(FMT_COMPILE("{:x}"), 0x42));
}

TEST(CompileTest, DynamicWidth) {
  EXPECT_EQ("  42foo  ",
            fmt::format(FMT_COMPILE("{:{}}{:{}}"), 42, 4, "foo", 5));
}

TEST(CompileTest, FormatTo) {
  char buf[8];
  auto end = fmt::format_to(buf, FMT_COMPILE("{}"), 42);
  *end = '\0';
  EXPECT_STREQ("42", buf);
  end = fmt::format_to(buf, FMT_COMPILE("{:x}"), 42);
  *end = '\0';
  EXPECT_STREQ("2a", buf);
}

TEST(CompileTest, FormatToNWithCompileMacro) {
  constexpr auto buffer_size = 8;
  char buffer[buffer_size];
  auto res = fmt::format_to_n(buffer, buffer_size, FMT_COMPILE("{}"), 42);
  *res.out = '\0';
  EXPECT_STREQ("42", buffer);
  res = fmt::format_to_n(buffer, buffer_size, FMT_COMPILE("{:x}"), 42);
  *res.out = '\0';
  EXPECT_STREQ("2a", buffer);
}

TEST(CompileTest, TextAndArg) {
  EXPECT_EQ(">>>42<<<", fmt::format(FMT_COMPILE(">>>{}<<<"), 42));
  EXPECT_EQ("42!", fmt::format(FMT_COMPILE("{}!"), 42));
}
#endif

#if __cplusplus >= 202002L
template <size_t max_string_length> struct test_string {
  template <typename T> constexpr bool operator==(const T& rhs) const noexcept {
    return (std::string_view(rhs).compare(buffer.data()) == 0);
  }

  std::array<char, max_string_length> buffer{};
};

template <size_t max_string_length, typename... Args>
consteval auto test_format(auto format, const Args&... args) {
  test_string<max_string_length> string{};
  fmt::format_to(string.buffer.data(), format, args...);
  return string;
}

TEST(CompileTimeFormattingTest, Bool) {
  {
    constexpr auto result = test_format<5>(FMT_COMPILE("{}"), true);
    EXPECT_EQ(result, "true");
  }
  {
    constexpr auto result = test_format<6>(FMT_COMPILE("{}"), false);
    EXPECT_EQ(result, "false");
  }
}

TEST(CompileTimeFormattingTest, Integer) {
  {
    constexpr auto result = test_format<3>(FMT_COMPILE("{}"), 42);
    EXPECT_EQ(result, "42");
  }
  {
    constexpr auto result = test_format<4>(FMT_COMPILE("{}"), 420);
    EXPECT_EQ(result, "420");
  }
  {
    constexpr auto result = test_format<6>(FMT_COMPILE("{} {}"), 42, 42);
    EXPECT_EQ(result, "42 42");
  }
  {
    constexpr auto result =
        test_format<6>(FMT_COMPILE("{} {}"), uint32_t{42}, uint64_t{42});
    EXPECT_EQ(result, "42 42");
  }
}

TEST(CompileTimeFormattingTest, String) {
  {
    constexpr auto result = test_format<3>(FMT_COMPILE("{}"), "42");
    EXPECT_EQ(result, "42");
  }
  {
    constexpr auto result =
        test_format<17>(FMT_COMPILE("{} is {}"), "The answer", "42");
    EXPECT_EQ(result, "The answer is 42");
  }
}

TEST(CompileTimeFormattingTest, Combination) {
  constexpr auto result =
      test_format<18>(FMT_COMPILE("{}, {}, {}"), 420, true, "answer");
  EXPECT_EQ(result, "420, true, answer");
}
#endif