localtime_to_utc test

Author: dirkvdb

chrono.cpp

@@ -177,14 +177,11 @@ std::optional<local_time_point> local_time_point_from_string(std::string_view st
 #ifdef HAVE_CPP20_CHRONO
 std::optional<time_point> localtime_to_utc(local_time_point dt, std::optional<choose> choice)
 {
-    if (choice.has_value()) {
-        return localtime_to_utc(zoned_time(std::chrono::current_zone(), dt, *choice));
-    } else {
-        return localtime_to_utc(zoned_time(std::chrono::current_zone(), dt));
-    }
+    auto choiseVal = choice.value_or(choose::latest);
+    return localtime_to_utc(zoned_time(std::chrono::current_zone(), dt, choiseVal), choiseVal);
 }
 
-std::optional<time_point> localtime_to_utc(zoned_time zt)
+std::optional<time_point> localtime_to_utc(zoned_time zt, choose choice)
 {
     auto localTimePoint = zt.get_local_time();
 
@@ -196,8 +193,12 @@ std::optional<time_point> localtime_to_utc(zoned_time zt)
         break;
     }
     case std::chrono::local_info::ambiguous: {
-        Log::warn("Ambiguous time point, taking the latest option");
-        utcTime = std::optional<time_point>(i.second.begin);
+        if (choice == choose::latest) {
+            utcTime = std::optional<time_point>(i.second.begin - i.second.save);
+        } else {
+            assert(choice == choose::earliest);
+            utcTime = std::optional<time_point>(i.first.end - i.first.save);
+        }
         break;
     }
     case std::chrono::local_info::nonexistent:

include/infra/chrono.h

@@ -189,7 +189,7 @@ inline std::string to_string(std::string_view format, chrono::local_time_point t
 }
 
 std::optional<time_point> localtime_to_utc(local_time_point dt, std::optional<choose> choice);
-std::optional<time_point> localtime_to_utc(zoned_time tp);
+std::optional<time_point> localtime_to_utc(zoned_time tp, choose choice);
 
 class DurationRecorder
 {

test/chronotest.cpp

@@ -13,6 +13,28 @@ TEST_CASE("ChronoTest.time_point_to_utc_string")
     CHECK("2017-02-01" == inf::chrono::to_string("%Y-%m-%d", date));
 }
 
+TEST_CASE("ChronoTest.time_point_to_utc_string_ambiguous")
+{
+    auto tp = chrono::local_time_point_from_string("2019-10-27 02:20:00.000", "%Y-%m-%d %H:%M:%S");
+    REQUIRE(tp.has_value());
+
+    {
+        auto utcTime = chrono::localtime_to_utc(*tp, chrono::choose::latest);
+        REQUIRE(utcTime.has_value());
+
+        chrono::time_point expected = std::chrono::sys_days(2019y / std::chrono::October / 27) + 1h;
+        CHECK(expected == *utcTime);
+    }
+
+    {
+        auto utcTime = chrono::localtime_to_utc(*tp, chrono::choose::earliest);
+        REQUIRE(utcTime.has_value());
+
+        chrono::time_point expected = std::chrono::sys_days(2019y / std::chrono::October / 27) + 0h;
+        CHECK(expected == *utcTime);
+    }
+}
+
 TEST_CASE("ChronoTest.time_point_to_string_custom_format")
 {
     chrono::date_point date = std::chrono::sys_days(2017y / std::chrono::February / 1);