Generalization of strftime/wcsftime function calls in tests

test/chrono-test.cc

@@ -42,6 +42,14 @@ auto make_second(int s) -> std::tm {
   return time;
 }
 
+std::string system_strftime(const std::string& format, const std::tm* timeptr,
+                            size_t maxsize = 1024) {
+  std::vector<char> output(maxsize);
+  auto size =
+      std::strftime(output.data(), output.size(), format.c_str(), timeptr);
+  return std::string(output.data(), size);
+}
+
 TEST(chrono_test, format_tm) {
   auto tm = std::tm();
   tm.tm_year = 116;
@@ -102,10 +110,9 @@ TEST(chrono_test, format_tm) {
     std::time_t t = std::mktime(&tm);
     tm = *std::localtime(&t);
 
-    char output[256] = {};
-    std::strftime(output, sizeof(output), iso_week_spec.c_str(), &tm);
     auto fmt_spec = std::string("{:").append(iso_week_spec).append("}");
-    EXPECT_EQ(output, fmt::format(fmt::runtime(fmt_spec), tm));
+    EXPECT_EQ(system_strftime(iso_week_spec, &tm),
+              fmt::format(fmt::runtime(fmt_spec), tm));
   }
 
   // Every day from 1970-01-01
@@ -113,10 +120,9 @@ TEST(chrono_test, format_tm) {
   for (std::time_t t = 6 * 3600; t < time_now; t += 86400) {
     tm = *std::localtime(&t);
 
-    char output[256] = {};
-    std::strftime(output, sizeof(output), iso_week_spec.c_str(), &tm);
     auto fmt_spec = std::string("{:").append(iso_week_spec).append("}");
-    EXPECT_EQ(output, fmt::format(fmt::runtime(fmt_spec), tm));
+    EXPECT_EQ(system_strftime(iso_week_spec, &tm),
+              fmt::format(fmt::runtime(fmt_spec), tm));
   }
 }
 
@@ -208,22 +214,20 @@ TEST(chrono_test, gmtime) {
   EXPECT_TRUE(equal(tm, fmt::gmtime(t)));
 }
 
-template <typename TimePoint> auto strftime(TimePoint tp) -> std::string {
+template <typename TimePoint> auto strftime_full(TimePoint tp) -> std::string {
   auto t = std::chrono::system_clock::to_time_t(tp);
   auto tm = *std::localtime(&t);
-  char output[256] = {};
-  std::strftime(output, sizeof(output), "%Y-%m-%d %H:%M:%S", &tm);
-  return output;
+  return system_strftime("%Y-%m-%d %H:%M:%S", &tm);
 }
 
 TEST(chrono_test, time_point) {
   auto t1 = std::chrono::system_clock::now();
-  EXPECT_EQ(strftime(t1), fmt::format("{:%Y-%m-%d %H:%M:%S}", t1));
-  EXPECT_EQ(strftime(t1), fmt::format("{}", t1));
+  EXPECT_EQ(strftime_full(t1), fmt::format("{:%Y-%m-%d %H:%M:%S}", t1));
+  EXPECT_EQ(strftime_full(t1), fmt::format("{}", t1));
   using time_point =
       std::chrono::time_point<std::chrono::system_clock, std::chrono::seconds>;
   auto t2 = time_point(std::chrono::seconds(42));
-  EXPECT_EQ(strftime(t2), fmt::format("{:%Y-%m-%d %H:%M:%S}", t2));
+  EXPECT_EQ(strftime_full(t2), fmt::format("{:%Y-%m-%d %H:%M:%S}", t2));
 
   std::vector<std::string> spec_list = {
       "%%",  "%n",  "%t",  "%Y",  "%EY", "%y",  "%Oy", "%Ey", "%C",  "%EC",
@@ -236,12 +240,12 @@ TEST(chrono_test, time_point) {
   for (const auto& spec : spec_list) {
     auto t = std::chrono::system_clock::to_time_t(t1);
     auto tm = *std::localtime(&t);
-    char output[256] = {};
-    std::strftime(output, sizeof(output), spec.c_str(), &tm);
+
+    auto sys_output = system_strftime(spec, &tm);
 
     auto fmt_spec = std::string("{:").append(spec).append("}");
-    EXPECT_EQ(output, fmt::format(fmt::runtime(fmt_spec), t1));
-    EXPECT_EQ(output, fmt::format(fmt::runtime(fmt_spec), tm));
+    EXPECT_EQ(sys_output, fmt::format(fmt::runtime(fmt_spec), t1));
+    EXPECT_EQ(sys_output, fmt::format(fmt::runtime(fmt_spec), tm));
   }
 }
 

test/xchar-test.cc

@@ -267,6 +267,14 @@ TEST(xchar_test, chrono) {
   EXPECT_EQ(fmt::format(L"{:%T}", tm), L"11:22:33");
 }
 
+std::wstring system_wcsftime(const std::wstring& format, const std::tm* timeptr,
+                             size_t maxsize = 1024) {
+  std::vector<wchar_t> output(maxsize);
+  auto size =
+      std::wcsftime(output.data(), output.size(), format.c_str(), timeptr);
+  return std::wstring(output.data(), size);
+}
+
 TEST(chrono_test, time_point) {
   auto t1 = std::chrono::system_clock::now();
 
@@ -282,12 +290,12 @@ TEST(chrono_test, time_point) {
   for (const auto& spec : spec_list) {
     auto t = std::chrono::system_clock::to_time_t(t1);
     auto tm = *std::localtime(&t);
-    wchar_t output[1024] = {};
-    std::wcsftime(output, sizeof(output) / sizeof(wchar_t), spec.c_str(), &tm);
+
+    auto sys_output = system_wcsftime(spec, &tm);
 
     auto fmt_spec = std::wstring(L"{:").append(spec).append(L"}");
-    EXPECT_EQ(output, fmt::format(fmt_spec, t1));
-    EXPECT_EQ(output, fmt::format(fmt_spec, tm));
+    EXPECT_EQ(sys_output, fmt::format(fmt_spec, t1));
+    EXPECT_EQ(sys_output, fmt::format(fmt_spec, tm));
   }
 }