Add initial support for weekday formatting

test/chrono-test.cc

@@ -8,9 +8,12 @@
 #include "fmt/chrono.h"
 
 #include "gtest-extra.h"  // EXPECT_THROW_MSG
+#include "util.h"         // get_locale
 
 using fmt::runtime;
 
+using testing::Contains;
+
 auto make_tm() -> std::tm {
   auto time = std::tm();
   time.tm_mday = 1;
@@ -246,26 +249,15 @@ auto format_tm(const std::tm& time, fmt::string_view spec,
   return os.str();
 }
 
+TEST(chrono_test, locale) {
+  auto loc = get_locale("ja_JP.utf8");
+  if (loc == std::locale::classic()) return;
 #  define EXPECT_TIME(spec, time, duration)                     \
     {                                                           \
       auto jp_loc = std::locale("ja_JP.utf8");                  \
       EXPECT_EQ(format_tm(time, spec, jp_loc),                  \
                 fmt::format(jp_loc, "{:L" spec "}", duration)); \
     }
-
-TEST(chrono_test, locale) {
-  auto loc_name = "ja_JP.utf8";
-  bool has_locale = false;
-  auto loc = std::locale();
-  try {
-    loc = std::locale(loc_name);
-    has_locale = true;
-  } catch (const std::runtime_error&) {
-  }
-  if (!has_locale) {
-    fmt::print("{} locale is missing.\n", loc_name);
-    return;
-  }
   EXPECT_TIME("%OH", make_hour(14), std::chrono::hours(14));
   EXPECT_TIME("%OI", make_hour(14), std::chrono::hours(14));
   EXPECT_TIME("%OM", make_minute(42), std::chrono::minutes(42));
@@ -384,4 +376,14 @@ TEST(chrono_test, unsigned_duration) {
   EXPECT_EQ("42s", fmt::format("{}", std::chrono::duration<unsigned>(42)));
 }
 
+TEST(chrono_test, format_weekday) {
+  auto loc = get_locale("ru_RU.UTF-8");
+  std::locale::global(loc);
+  EXPECT_EQ(fmt::format("{}", fmt::weekday(1)), "Mon");
+  if (loc != std::locale::classic()) {
+    EXPECT_THAT((std::vector<std::string>{"пн", "Пн"}),
+                Contains(fmt::format(loc, "{:L}", fmt::weekday(1))));
+  }
+}
+
 #endif  // FMT_STATIC_THOUSANDS_SEPARATOR

test/unicode-test.cc

@@ -5,7 +5,25 @@
 //
 // For the license information refer to format.h.
 
-#include "fmt/core.h"
-#include "gtest/gtest.h"
+#include <vector>
 
-TEST(unicode_test, is_utf8) { EXPECT_TRUE(fmt::detail::is_utf8()); }
+#include "fmt/chrono.h"
+#include "gmock/gmock.h"
+#include "util.h"  // get_locale
+
+using testing::Contains;
+
+TEST(unicode_test, is_utf8) { EXPECT_TRUE(fmt::detail::is_utf8()); }
+
+TEST(unicode_test, legacy_locale) {
+  auto loc = get_locale("ru_RU.CP1251");
+  if (loc == std::locale::classic()) return;
+  try {
+    EXPECT_THAT(
+        (std::vector<std::string>{"День недели: пн", "День недели: Пн"}),
+        Contains(fmt::format(loc, "День недели: {:L}", fmt::weekday(1))));
+  } catch (const fmt::format_error& e) {
+    // Formatting can fail due to unsupported encoding.
+    fmt::print("Format error: {}\n", e.what());
+  }
+}

test/util.cc

@@ -26,3 +26,12 @@ fmt::buffered_file open_buffered_file(FILE** fp) {
 #endif
   return f;
 }
+
+std::locale get_locale(const char* name) {
+  try {
+    return std::locale(name);
+  } catch (const std::runtime_error&) {
+    fmt::print(stderr, "{} locale is missing.\n", name);
+  }
+  return std::locale::classic();
+}

test/util.h

@@ -7,6 +7,7 @@
 
 #include <cstdarg>
 #include <cstdio>
+#include <locale>
 #include <string>
 
 #include "fmt/os.h"
@@ -75,3 +76,6 @@ class date {
   int month() const { return month_; }
   int day() const { return day_; }
 };
+
+// Returns a locale with the given name if available or classic locale othewise.
+std::locale get_locale(const char* name);