LibJS: Implement Temporal.Now.plainTimeISO()

Author: https://github.com/linusg
Commit: https://github.com/SerenityOS/serenity/commit/5e64156fce5
Pull-request: https://github.com/SerenityOS/serenity/pull/9078
Reviewed-by: https://github.com/IdanHo ✅

Userland/Libraries/LibJS/Runtime/CommonPropertyNames.h

@@ -291,6 +291,7 @@ namespace JS {
     P(plainDateISO)                          \
     P(plainDateTime)                         \
     P(plainDateTimeISO)                      \
+    P(plainTimeISO)                          \
     P(pop)                                   \
     P(pow)                                   \
     P(preventExtensions)                     \

Userland/Libraries/LibJS/Runtime/Temporal/Now.cpp

@@ -11,6 +11,7 @@
 #include <LibJS/Runtime/Temporal/Now.h>
 #include <LibJS/Runtime/Temporal/PlainDate.h>
 #include <LibJS/Runtime/Temporal/PlainDateTime.h>
+#include <LibJS/Runtime/Temporal/PlainTime.h>
 #include <LibJS/Runtime/Temporal/TimeZone.h>
 #include <time.h>
 
@@ -38,6 +39,7 @@ void Now::initialize(GlobalObject& global_object)
     define_native_function(vm.names.plainDateTimeISO, plain_date_time_iso, 0, attr);
     define_native_function(vm.names.plainDate, plain_date, 1, attr);
     define_native_function(vm.names.plainDateISO, plain_date_iso, 0, attr);
+    define_native_function(vm.names.plainTimeISO, plain_time_iso, 0, attr);
 }
 
 // 2.2.1 Temporal.Now.timeZone ( ), https://tc39.es/proposal-temporal/#sec-temporal.now.timezone
@@ -112,6 +114,24 @@ JS_DEFINE_NATIVE_FUNCTION(Now::plain_date_iso)
     return create_temporal_date(global_object, date_time->iso_year(), date_time->iso_month(), date_time->iso_day(), date_time->calendar());
 }
 
+// 2.2.9 Temporal.Now.plainTimeISO ( [ temporalTimeZoneLike ] ), https://tc39.es/proposal-temporal/#sec-temporal.now.plaintimeiso
+JS_DEFINE_NATIVE_FUNCTION(Now::plain_time_iso)
+{
+    auto temporal_time_zone_like = vm.argument(0);
+
+    // 1. Let calendar be ? GetISO8601Calendar().
+    // NOTE: No exception check needed for GetISO8601Calendar, see https://github.com/tc39/proposal-temporal/pull/1643
+    auto* calendar = get_iso8601_calendar(global_object);
+
+    // 2. Let dateTime be ? SystemDateTime(temporalTimeZoneLike, calendar).
+    auto date_time = system_date_time(global_object, temporal_time_zone_like, calendar);
+    if (vm.exception())
+        return {};
+
+    // 3. Return ? CreateTemporalTime(dateTime.[[ISOHour]], dateTime.[[ISOMinute]], dateTime.[[ISOSecond]], dateTime.[[ISOMillisecond]], dateTime.[[ISOMicrosecond]], dateTime.[[ISONanosecond]]).
+    return create_temporal_time(global_object, date_time->iso_hour(), date_time->iso_minute(), date_time->iso_second(), date_time->iso_millisecond(), date_time->iso_microsecond(), date_time->iso_nanosecond());
+}
+
 // 2.3.1 SystemTimeZone ( ), https://tc39.es/proposal-temporal/#sec-temporal-systemtimezone
 TimeZone* system_time_zone(GlobalObject& global_object)
 {

Userland/Libraries/LibJS/Runtime/Temporal/Now.h

@@ -25,6 +25,7 @@ private:
     JS_DECLARE_NATIVE_FUNCTION(plain_date_time_iso);
     JS_DECLARE_NATIVE_FUNCTION(plain_date);
     JS_DECLARE_NATIVE_FUNCTION(plain_date_iso);
+    JS_DECLARE_NATIVE_FUNCTION(plain_time_iso);
 };
 
 TimeZone* system_time_zone(GlobalObject&);

Userland/Libraries/LibJS/Tests/builtins/Temporal/Now/Now.plainTimeISO.js

@@ -0,0 +1,22 @@
+describe("correct behavior", () => {
+    test("length is 0", () => {
+        expect(Temporal.Now.plainTimeISO).toHaveLength(0);
+    });
+
+    test("basic functionality", () => {
+        const plainTime = Temporal.Now.plainTimeISO();
+        expect(plainTime).toBeInstanceOf(Temporal.PlainTime);
+        expect(plainTime.calendar.id).toBe("iso8601");
+    });
+
+    test("custom time zone", () => {
+        const timeZone = {
+            getOffsetNanosecondsFor() {
+                return 86400000000000;
+            },
+        };
+        const plainTime = Temporal.Now.plainTimeISO();
+        const plainTimeWithOffset = Temporal.Now.plainTimeISO(timeZone);
+        // FIXME: Compare these in a sensible way
+    });
+});