fmt/test/printf-test.cc

578 lines
20 KiB
C++

// Formatting library for C++ - printf tests
//
// Copyright (c) 2012 - present, Victor Zverovich
// All rights reserved.
//
// For the license information refer to format.h.
#include <cctype>
#include <climits>
#include <cstring>
#include "fmt/core.h"
#include "fmt/printf.h"
#include "gtest-extra.h"
#include "util.h"
using fmt::format;
using fmt::format_error;
const unsigned BIG_NUM = INT_MAX + 1u;
// Makes format string argument positional.
static std::string make_positional(fmt::string_view format) {
std::string s(format.data(), format.size());
s.replace(s.find('%'), 1, "%1$");
return s;
}
static std::wstring make_positional(fmt::wstring_view format) {
std::wstring s(format.data(), format.size());
s.replace(s.find(L'%'), 1, L"%1$");
return s;
}
// A wrapper around fmt::sprintf to workaround bogus warnings about invalid
// format strings in MSVC.
template <typename... Args>
std::string test_sprintf(fmt::string_view format, const Args&... args) {
return fmt::sprintf(format, args...);
}
template <typename... Args>
std::wstring test_sprintf(fmt::wstring_view format, const Args&... args) {
return fmt::sprintf(format, args...);
}
#define EXPECT_PRINTF(expected_output, format, arg) \
EXPECT_EQ(expected_output, test_sprintf(format, arg)) \
<< "format: " << format; \
EXPECT_EQ(expected_output, fmt::sprintf(make_positional(format), arg))
TEST(PrintfTest, NoArgs) {
EXPECT_EQ("test", test_sprintf("test"));
EXPECT_EQ(L"test", fmt::sprintf(L"test"));
}
TEST(PrintfTest, Escape) {
EXPECT_EQ("%", test_sprintf("%%"));
EXPECT_EQ("before %", test_sprintf("before %%"));
EXPECT_EQ("% after", test_sprintf("%% after"));
EXPECT_EQ("before % after", test_sprintf("before %% after"));
EXPECT_EQ("%s", test_sprintf("%%s"));
EXPECT_EQ(L"%", fmt::sprintf(L"%%"));
EXPECT_EQ(L"before %", fmt::sprintf(L"before %%"));
EXPECT_EQ(L"% after", fmt::sprintf(L"%% after"));
EXPECT_EQ(L"before % after", fmt::sprintf(L"before %% after"));
EXPECT_EQ(L"%s", fmt::sprintf(L"%%s"));
}
TEST(PrintfTest, PositionalArgs) {
EXPECT_EQ("42", test_sprintf("%1$d", 42));
EXPECT_EQ("before 42", test_sprintf("before %1$d", 42));
EXPECT_EQ("42 after", test_sprintf("%1$d after", 42));
EXPECT_EQ("before 42 after", test_sprintf("before %1$d after", 42));
EXPECT_EQ("answer = 42", test_sprintf("%1$s = %2$d", "answer", 42));
EXPECT_EQ("42 is the answer", test_sprintf("%2$d is the %1$s", "answer", 42));
EXPECT_EQ("abracadabra", test_sprintf("%1$s%2$s%1$s", "abra", "cad"));
}
TEST(PrintfTest, AutomaticArgIndexing) {
EXPECT_EQ("abc", test_sprintf("%c%c%c", 'a', 'b', 'c'));
}
TEST(PrintfTest, NumberIsTooBigInArgIndex) {
EXPECT_THROW_MSG(test_sprintf(format("%{}$", BIG_NUM)), format_error,
"number is too big");
EXPECT_THROW_MSG(test_sprintf(format("%{}$d", BIG_NUM)), format_error,
"number is too big");
}
TEST(PrintfTest, SwitchArgIndexing) {
EXPECT_THROW_MSG(test_sprintf("%1$d%", 1, 2), format_error,
"cannot switch from manual to automatic argument indexing");
EXPECT_THROW_MSG(test_sprintf(format("%1$d%{}d", BIG_NUM), 1, 2),
format_error, "number is too big");
EXPECT_THROW_MSG(test_sprintf("%1$d%d", 1, 2), format_error,
"cannot switch from manual to automatic argument indexing");
EXPECT_THROW_MSG(test_sprintf("%d%1$", 1, 2), format_error,
"cannot switch from automatic to manual argument indexing");
EXPECT_THROW_MSG(test_sprintf(format("%d%{}$d", BIG_NUM), 1, 2), format_error,
"number is too big");
EXPECT_THROW_MSG(test_sprintf("%d%1$d", 1, 2), format_error,
"cannot switch from automatic to manual argument indexing");
// Indexing errors override width errors.
EXPECT_THROW_MSG(test_sprintf(format("%d%1${}d", BIG_NUM), 1, 2),
format_error, "number is too big");
EXPECT_THROW_MSG(test_sprintf(format("%1$d%{}d", BIG_NUM), 1, 2),
format_error, "number is too big");
}
TEST(PrintfTest, InvalidArgIndex) {
EXPECT_THROW_MSG(test_sprintf("%0$d", 42), format_error,
"argument index out of range");
EXPECT_THROW_MSG(test_sprintf("%2$d", 42), format_error,
"argument index out of range");
EXPECT_THROW_MSG(test_sprintf(format("%{}$d", INT_MAX), 42), format_error,
"argument index out of range");
EXPECT_THROW_MSG(test_sprintf("%2$", 42), format_error,
"argument index out of range");
EXPECT_THROW_MSG(test_sprintf(format("%{}$d", BIG_NUM), 42), format_error,
"number is too big");
}
TEST(PrintfTest, DefaultAlignRight) {
EXPECT_PRINTF(" 42", "%5d", 42);
EXPECT_PRINTF(" abc", "%5s", "abc");
}
TEST(PrintfTest, ZeroFlag) {
EXPECT_PRINTF("00042", "%05d", 42);
EXPECT_PRINTF("-0042", "%05d", -42);
EXPECT_PRINTF("00042", "%05d", 42);
EXPECT_PRINTF("-0042", "%05d", -42);
EXPECT_PRINTF("-004.2", "%06g", -4.2);
EXPECT_PRINTF("+00042", "%00+6d", 42);
// '0' flag is ignored for non-numeric types.
EXPECT_PRINTF("0000x", "%05c", 'x');
}
TEST(PrintfTest, PlusFlag) {
EXPECT_PRINTF("+42", "%+d", 42);
EXPECT_PRINTF("-42", "%+d", -42);
EXPECT_PRINTF("+0042", "%+05d", 42);
EXPECT_PRINTF("+0042", "%0++5d", 42);
// '+' flag is ignored for non-numeric types.
EXPECT_PRINTF("x", "%+c", 'x');
}
TEST(PrintfTest, MinusFlag) {
EXPECT_PRINTF("abc ", "%-5s", "abc");
EXPECT_PRINTF("abc ", "%0--5s", "abc");
}
TEST(PrintfTest, SpaceFlag) {
EXPECT_PRINTF(" 42", "% d", 42);
EXPECT_PRINTF("-42", "% d", -42);
EXPECT_PRINTF(" 0042", "% 05d", 42);
EXPECT_PRINTF(" 0042", "%0 5d", 42);
// ' ' flag is ignored for non-numeric types.
EXPECT_PRINTF("x", "% c", 'x');
}
TEST(PrintfTest, HashFlag) {
EXPECT_PRINTF("042", "%#o", 042);
EXPECT_PRINTF(fmt::format("0{:o}", static_cast<unsigned>(-042)), "%#o", -042);
EXPECT_PRINTF("0", "%#o", 0);
EXPECT_PRINTF("0x42", "%#x", 0x42);
EXPECT_PRINTF("0X42", "%#X", 0x42);
EXPECT_PRINTF(fmt::format("0x{:x}", static_cast<unsigned>(-0x42)), "%#x",
-0x42);
EXPECT_PRINTF("0", "%#x", 0);
EXPECT_PRINTF("0x0042", "%#06x", 0x42);
EXPECT_PRINTF("0x0042", "%0##6x", 0x42);
EXPECT_PRINTF("-42.000000", "%#f", -42.0);
EXPECT_PRINTF("-42.000000", "%#F", -42.0);
char buffer[BUFFER_SIZE];
safe_sprintf(buffer, "%#e", -42.0);
EXPECT_PRINTF(buffer, "%#e", -42.0);
safe_sprintf(buffer, "%#E", -42.0);
EXPECT_PRINTF(buffer, "%#E", -42.0);
EXPECT_PRINTF("-42.0000", "%#g", -42.0);
EXPECT_PRINTF("-42.0000", "%#G", -42.0);
safe_sprintf(buffer, "%#a", 16.0);
EXPECT_PRINTF(buffer, "%#a", 16.0);
safe_sprintf(buffer, "%#A", 16.0);
EXPECT_PRINTF(buffer, "%#A", 16.0);
// '#' flag is ignored for non-numeric types.
EXPECT_PRINTF("x", "%#c", 'x');
}
TEST(PrintfTest, Width) {
EXPECT_PRINTF(" abc", "%5s", "abc");
// Width cannot be specified twice.
EXPECT_THROW_MSG(test_sprintf("%5-5d", 42), format_error,
"invalid type specifier");
EXPECT_THROW_MSG(test_sprintf(format("%{}d", BIG_NUM), 42), format_error,
"number is too big");
EXPECT_THROW_MSG(test_sprintf(format("%1${}d", BIG_NUM), 42), format_error,
"number is too big");
}
TEST(PrintfTest, DynamicWidth) {
EXPECT_EQ(" 42", test_sprintf("%*d", 5, 42));
EXPECT_EQ("42 ", test_sprintf("%*d", -5, 42));
EXPECT_THROW_MSG(test_sprintf("%*d", 5.0, 42), format_error,
"width is not integer");
EXPECT_THROW_MSG(test_sprintf("%*d"), format_error,
"argument index out of range");
EXPECT_THROW_MSG(test_sprintf("%*d", BIG_NUM, 42), format_error,
"number is too big");
}
TEST(PrintfTest, IntPrecision) {
EXPECT_PRINTF("00042", "%.5d", 42);
EXPECT_PRINTF("-00042", "%.5d", -42);
EXPECT_PRINTF("00042", "%.5x", 0x42);
EXPECT_PRINTF("0x00042", "%#.5x", 0x42);
EXPECT_PRINTF("00042", "%.5o", 042);
EXPECT_PRINTF("00042", "%#.5o", 042);
EXPECT_PRINTF(" 00042", "%7.5d", 42);
EXPECT_PRINTF(" 00042", "%7.5x", 0x42);
EXPECT_PRINTF(" 0x00042", "%#10.5x", 0x42);
EXPECT_PRINTF(" 00042", "%7.5o", 042);
EXPECT_PRINTF(" 00042", "%#10.5o", 042);
EXPECT_PRINTF("00042 ", "%-7.5d", 42);
EXPECT_PRINTF("00042 ", "%-7.5x", 0x42);
EXPECT_PRINTF("0x00042 ", "%-#10.5x", 0x42);
EXPECT_PRINTF("00042 ", "%-7.5o", 042);
EXPECT_PRINTF("00042 ", "%-#10.5o", 042);
}
TEST(PrintfTest, FloatPrecision) {
char buffer[BUFFER_SIZE];
safe_sprintf(buffer, "%.3e", 1234.5678);
EXPECT_PRINTF(buffer, "%.3e", 1234.5678);
EXPECT_PRINTF("1234.568", "%.3f", 1234.5678);
safe_sprintf(buffer, "%.3g", 1234.5678);
EXPECT_PRINTF(buffer, "%.3g", 1234.5678);
safe_sprintf(buffer, "%.3a", 1234.5678);
EXPECT_PRINTF(buffer, "%.3a", 1234.5678);
}
TEST(PrintfTest, IgnorePrecisionForNonNumericArg) {
EXPECT_PRINTF("abc", "%.5s", "abc");
}
TEST(PrintfTest, DynamicPrecision) {
EXPECT_EQ("00042", test_sprintf("%.*d", 5, 42));
EXPECT_EQ("42", test_sprintf("%.*d", -5, 42));
EXPECT_THROW_MSG(test_sprintf("%.*d", 5.0, 42), format_error,
"precision is not integer");
EXPECT_THROW_MSG(test_sprintf("%.*d"), format_error,
"argument index out of range");
EXPECT_THROW_MSG(test_sprintf("%.*d", BIG_NUM, 42), format_error,
"number is too big");
if (sizeof(long long) != sizeof(int)) {
long long prec = static_cast<long long>(INT_MIN) - 1;
EXPECT_THROW_MSG(test_sprintf("%.*d", prec, 42), format_error,
"number is too big");
}
}
template <typename T> struct make_signed { typedef T type; };
#define SPECIALIZE_MAKE_SIGNED(T, S) \
template <> struct make_signed<T> { typedef S type; }
SPECIALIZE_MAKE_SIGNED(char, signed char);
SPECIALIZE_MAKE_SIGNED(unsigned char, signed char);
SPECIALIZE_MAKE_SIGNED(unsigned short, short);
SPECIALIZE_MAKE_SIGNED(unsigned, int);
SPECIALIZE_MAKE_SIGNED(unsigned long, long);
SPECIALIZE_MAKE_SIGNED(unsigned long long, long long);
// Test length format specifier ``length_spec``.
template <typename T, typename U>
void TestLength(const char* length_spec, U value) {
long long signed_value = 0;
unsigned long long unsigned_value = 0;
// Apply integer promotion to the argument.
using std::numeric_limits;
unsigned long long max = numeric_limits<U>::max();
using fmt::internal::const_check;
if (const_check(max <= static_cast<unsigned>(numeric_limits<int>::max()))) {
signed_value = static_cast<int>(value);
unsigned_value = static_cast<unsigned>(value);
} else if (const_check(max <= numeric_limits<unsigned>::max())) {
signed_value = static_cast<unsigned>(value);
unsigned_value = static_cast<unsigned>(value);
}
if (sizeof(U) <= sizeof(int) && sizeof(int) < sizeof(T)) {
signed_value = static_cast<long long>(value);
unsigned_value =
static_cast<typename std::make_unsigned<unsigned>::type>(value);
} else {
signed_value = static_cast<typename make_signed<T>::type>(value);
unsigned_value = static_cast<typename std::make_unsigned<T>::type>(value);
}
std::ostringstream os;
os << signed_value;
EXPECT_PRINTF(os.str(), fmt::format("%{}d", length_spec), value);
EXPECT_PRINTF(os.str(), fmt::format("%{}i", length_spec), value);
os.str("");
os << unsigned_value;
EXPECT_PRINTF(os.str(), fmt::format("%{}u", length_spec), value);
os.str("");
os << std::oct << unsigned_value;
EXPECT_PRINTF(os.str(), fmt::format("%{}o", length_spec), value);
os.str("");
os << std::hex << unsigned_value;
EXPECT_PRINTF(os.str(), fmt::format("%{}x", length_spec), value);
os.str("");
os << std::hex << std::uppercase << unsigned_value;
EXPECT_PRINTF(os.str(), fmt::format("%{}X", length_spec), value);
}
template <typename T> void TestLength(const char* length_spec) {
T min = std::numeric_limits<T>::min(), max = std::numeric_limits<T>::max();
TestLength<T>(length_spec, 42);
TestLength<T>(length_spec, -42);
TestLength<T>(length_spec, min);
TestLength<T>(length_spec, max);
TestLength<T>(length_spec, static_cast<long long>(min) - 1);
unsigned long long long_long_max = std::numeric_limits<long long>::max();
if (static_cast<unsigned long long>(max) < long_long_max)
TestLength<T>(length_spec, static_cast<long long>(max) + 1);
TestLength<T>(length_spec, std::numeric_limits<short>::min());
TestLength<T>(length_spec, std::numeric_limits<unsigned short>::max());
TestLength<T>(length_spec, std::numeric_limits<int>::min());
TestLength<T>(length_spec, std::numeric_limits<int>::max());
TestLength<T>(length_spec, std::numeric_limits<unsigned>::min());
TestLength<T>(length_spec, std::numeric_limits<unsigned>::max());
TestLength<T>(length_spec, std::numeric_limits<long long>::min());
TestLength<T>(length_spec, std::numeric_limits<long long>::max());
TestLength<T>(length_spec, std::numeric_limits<unsigned long long>::min());
TestLength<T>(length_spec, std::numeric_limits<unsigned long long>::max());
}
TEST(PrintfTest, Length) {
TestLength<char>("hh");
TestLength<signed char>("hh");
TestLength<unsigned char>("hh");
TestLength<short>("h");
TestLength<unsigned short>("h");
TestLength<long>("l");
TestLength<unsigned long>("l");
TestLength<long long>("ll");
TestLength<unsigned long long>("ll");
TestLength<intmax_t>("j");
TestLength<std::size_t>("z");
TestLength<std::ptrdiff_t>("t");
long double max = std::numeric_limits<long double>::max();
EXPECT_PRINTF(fmt::format("{:.6}", max), "%g", max);
EXPECT_PRINTF(fmt::format("{:.6}", max), "%Lg", max);
}
TEST(PrintfTest, Bool) {
EXPECT_PRINTF("1", "%d", true);
EXPECT_PRINTF("true", "%s", true);
}
TEST(PrintfTest, Int) {
EXPECT_PRINTF("-42", "%d", -42);
EXPECT_PRINTF("-42", "%i", -42);
unsigned u = 0 - 42u;
EXPECT_PRINTF(fmt::format("{}", u), "%u", -42);
EXPECT_PRINTF(fmt::format("{:o}", u), "%o", -42);
EXPECT_PRINTF(fmt::format("{:x}", u), "%x", -42);
EXPECT_PRINTF(fmt::format("{:X}", u), "%X", -42);
}
TEST(PrintfTest, long_long) {
// fmt::printf allows passing long long arguments to %d without length
// specifiers.
long long max = std::numeric_limits<long long>::max();
EXPECT_PRINTF(fmt::format("{}", max), "%d", max);
}
TEST(PrintfTest, Float) {
EXPECT_PRINTF("392.650000", "%f", 392.65);
EXPECT_PRINTF("392.65", "%.2f", 392.65);
EXPECT_PRINTF("392.6", "%.1f", 392.65);
EXPECT_PRINTF("393", "%.f", 392.65);
EXPECT_PRINTF("392.650000", "%F", 392.65);
char buffer[BUFFER_SIZE];
safe_sprintf(buffer, "%e", 392.65);
EXPECT_PRINTF(buffer, "%e", 392.65);
safe_sprintf(buffer, "%E", 392.65);
EXPECT_PRINTF(buffer, "%E", 392.65);
EXPECT_PRINTF("392.65", "%g", 392.65);
EXPECT_PRINTF("392.65", "%G", 392.65);
safe_sprintf(buffer, "%a", -392.65);
EXPECT_EQ(buffer, format("{:a}", -392.65));
safe_sprintf(buffer, "%A", -392.65);
EXPECT_EQ(buffer, format("{:A}", -392.65));
}
TEST(PrintfTest, Inf) {
double inf = std::numeric_limits<double>::infinity();
for (const char* type = "fega"; *type; ++type) {
EXPECT_PRINTF("inf", fmt::format("%{}", *type), inf);
char upper = static_cast<char>(std::toupper(*type));
EXPECT_PRINTF("INF", fmt::format("%{}", upper), inf);
}
}
TEST(PrintfTest, Char) {
EXPECT_PRINTF("x", "%c", 'x');
int max = std::numeric_limits<int>::max();
EXPECT_PRINTF(fmt::format("{}", static_cast<char>(max)), "%c", max);
// EXPECT_PRINTF("x", "%lc", L'x');
EXPECT_PRINTF(L"x", L"%c", L'x');
EXPECT_PRINTF(fmt::format(L"{}", static_cast<wchar_t>(max)), L"%c", max);
}
TEST(PrintfTest, String) {
EXPECT_PRINTF("abc", "%s", "abc");
const char* null_str = FMT_NULL;
EXPECT_PRINTF("(null)", "%s", null_str);
EXPECT_PRINTF(" (null)", "%10s", null_str);
EXPECT_PRINTF(L"abc", L"%s", L"abc");
const wchar_t* null_wstr = FMT_NULL;
EXPECT_PRINTF(L"(null)", L"%s", null_wstr);
EXPECT_PRINTF(L" (null)", L"%10s", null_wstr);
}
TEST(PrintfTest, Pointer) {
int n;
void* p = &n;
EXPECT_PRINTF(fmt::format("{}", p), "%p", p);
p = FMT_NULL;
EXPECT_PRINTF("(nil)", "%p", p);
EXPECT_PRINTF(" (nil)", "%10p", p);
const char* s = "test";
EXPECT_PRINTF(fmt::format("{:p}", s), "%p", s);
const char* null_str = FMT_NULL;
EXPECT_PRINTF("(nil)", "%p", null_str);
p = &n;
EXPECT_PRINTF(fmt::format(L"{}", p), L"%p", p);
p = FMT_NULL;
EXPECT_PRINTF(L"(nil)", L"%p", p);
EXPECT_PRINTF(L" (nil)", L"%10p", p);
const wchar_t* w = L"test";
EXPECT_PRINTF(fmt::format(L"{:p}", w), L"%p", w);
const wchar_t* null_wstr = FMT_NULL;
EXPECT_PRINTF(L"(nil)", L"%p", null_wstr);
}
TEST(PrintfTest, Location) {
// TODO: test %n
}
enum E { A = 42 };
TEST(PrintfTest, Enum) { EXPECT_PRINTF("42", "%d", A); }
#if FMT_USE_FILE_DESCRIPTORS
TEST(PrintfTest, Examples) {
const char* weekday = "Thursday";
const char* month = "August";
int day = 21;
EXPECT_WRITE(stdout, fmt::printf("%1$s, %3$d %2$s", weekday, month, day),
"Thursday, 21 August");
}
TEST(PrintfTest, PrintfError) {
fmt::file read_end, write_end;
fmt::file::pipe(read_end, write_end);
int result = fmt::fprintf(read_end.fdopen("r").get(), "test");
EXPECT_LT(result, 0);
}
#endif
TEST(PrintfTest, WideString) { EXPECT_EQ(L"abc", fmt::sprintf(L"%s", L"abc")); }
TEST(PrintfTest, PrintfCustom) {
EXPECT_EQ("abc", test_sprintf("%s", TestString("abc")));
}
TEST(PrintfTest, OStream) {
std::ostringstream os;
int ret = fmt::fprintf(os, "Don't %s!", "panic");
EXPECT_EQ("Don't panic!", os.str());
EXPECT_EQ(12, ret);
}
TEST(PrintfTest, VPrintf) {
fmt::format_arg_store<fmt::printf_context, int> as{42};
fmt::basic_format_args<fmt::printf_context> args(as);
EXPECT_EQ(fmt::vsprintf("%d", args), "42");
EXPECT_WRITE(stdout, fmt::vprintf("%d", args), "42");
EXPECT_WRITE(stdout, fmt::vfprintf(stdout, "%d", args), "42");
EXPECT_WRITE(stdout, fmt::vfprintf(std::cout, "%d", args), "42");
}
template <typename... Args>
void check_format_string_regression(fmt::string_view s, const Args&... args) {
fmt::sprintf(s, args...);
}
TEST(PrintfTest, CheckFormatStringRegression) {
check_format_string_regression("%c%s", 'x', "");
}
TEST(PrintfTest, VSPrintfMakeArgsExample) {
fmt::format_arg_store<fmt::printf_context, int, const char*> as{42,
"something"};
fmt::basic_format_args<fmt::printf_context> args(as);
EXPECT_EQ("[42] something happened", fmt::vsprintf("[%d] %s happened", args));
auto as2 = fmt::make_printf_args(42, "something");
fmt::basic_format_args<fmt::printf_context> args2(as2);
EXPECT_EQ("[42] something happened",
fmt::vsprintf("[%d] %s happened", args2));
// the older gcc versions can't cast the return value
#if !defined(__GNUC__) || (__GNUC__ > 4)
EXPECT_EQ("[42] something happened",
fmt::vsprintf("[%d] %s happened",
fmt::make_printf_args(42, "something")));
#endif
}
TEST(PrintfTest, VSPrintfMakeWArgsExample) {
fmt::format_arg_store<fmt::wprintf_context, int, const wchar_t*> as{
42, L"something"};
fmt::basic_format_args<fmt::wprintf_context> args(as);
EXPECT_EQ(L"[42] something happened",
fmt::vsprintf(L"[%d] %s happened", args));
auto as2 = fmt::make_wprintf_args(42, L"something");
fmt::basic_format_args<fmt::wprintf_context> args2(as2);
EXPECT_EQ(L"[42] something happened",
fmt::vsprintf(L"[%d] %s happened", args2));
// the older gcc versions can't cast the return value
#if !defined(__GNUC__) || (__GNUC__ > 4)
EXPECT_EQ(L"[42] something happened",
fmt::vsprintf(L"[%d] %s happened",
fmt::make_wprintf_args(42, L"something")));
#endif
}
TEST(PrintfTest, snprintf) {
char buffer[4] = "xxx";
auto result = fmt::snprintf(buffer, 0, "test");
EXPECT_EQ("xxx", fmt::to_string_view(buffer));
EXPECT_EQ(4u, result.size);
EXPECT_EQ(buffer, result.out);
result = fmt::snprintf(buffer, 2, "test");
EXPECT_EQ("tex", fmt::to_string_view(buffer));
EXPECT_EQ(4u, result.size);
EXPECT_EQ(buffer + 2, result.out);
result = fmt::snprintf(buffer, 3, "test");
EXPECT_EQ("tes", fmt::to_string_view(buffer));
EXPECT_EQ(4u, result.size);
EXPECT_EQ(buffer + 3, result.out);
result = fmt::snprintf(buffer, 4, "test");
EXPECT_EQ("test", std::string(buffer, 4));
EXPECT_EQ(4u, result.size);
EXPECT_EQ(buffer + 4, result.out);
}