LibJS: Implement Temporal.Now.zonedDateTimeISO()

Userland/Libraries/LibJS/Runtime/CommonPropertyNames.h

@@ -414,7 +414,8 @@ namespace JS {
     P(writable)                              \
     P(year)                                  \
     P(years)                                 \
-    P(zonedDateTime)
+    P(zonedDateTime)                         \
+    P(zonedDateTimeISO)
 
 struct CommonPropertyNames {
     PropertyName and_ { "and", PropertyName::StringMayBeNumber::No };

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

@@ -39,6 +39,7 @@ void Now::initialize(GlobalObject& global_object)
     define_native_function(vm.names.plainDateTime, plain_date_time, 1, attr);
     define_native_function(vm.names.plainDateTimeISO, plain_date_time_iso, 0, attr);
     define_native_function(vm.names.zonedDateTime, zoned_date_time, 1, attr);
+    define_native_function(vm.names.zonedDateTimeISO, zoned_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);
@@ -90,6 +91,18 @@ JS_DEFINE_NATIVE_FUNCTION(Now::zoned_date_time)
     return system_zoned_date_time(global_object, temporal_time_zone_like, calendar);
 }
 
+// 2.2.6 Temporal.Now.zonedDateTimeISO ( [ temporalTimeZoneLike ] ), https://tc39.es/proposal-temporal/#sec-temporal.now.zoneddatetimeiso
+JS_DEFINE_NATIVE_FUNCTION(Now::zoned_date_time_iso)
+{
+    auto temporal_time_zone_like = vm.argument(0);
+
+    // 1, Let calendar be ! GetISO8601Calendar().
+    auto* calendar = get_iso8601_calendar(global_object);
+
+    // 2. Return ? SystemZonedDateTime(temporalTimeZoneLike, calendar).
+    return system_zoned_date_time(global_object, temporal_time_zone_like, calendar);
+}
+
 // 2.2.7 Temporal.Now.plainDate ( calendar [ , temporalTimeZoneLike ] ), https://tc39.es/proposal-temporal/#sec-temporal.now.plaindate
 JS_DEFINE_NATIVE_FUNCTION(Now::plain_date)
 {

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

@@ -24,6 +24,7 @@ private:
     JS_DECLARE_NATIVE_FUNCTION(plain_date_time);
     JS_DECLARE_NATIVE_FUNCTION(plain_date_time_iso);
     JS_DECLARE_NATIVE_FUNCTION(zoned_date_time);
+    JS_DECLARE_NATIVE_FUNCTION(zoned_date_time_iso);
     JS_DECLARE_NATIVE_FUNCTION(plain_date);
     JS_DECLARE_NATIVE_FUNCTION(plain_date_iso);
     JS_DECLARE_NATIVE_FUNCTION(plain_time_iso);

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

@@ -0,0 +1,19 @@
+describe("correct behavior", () => {
+    test("length is 0", () => {
+        expect(Temporal.Now.zonedDateTimeISO).toHaveLength(0);
+    });
+
+    test("basic functionality", () => {
+        const zonedDateTime = Temporal.Now.zonedDateTimeISO();
+        expect(zonedDateTime).toBeInstanceOf(Temporal.ZonedDateTime);
+        expect(zonedDateTime.calendar.id).toBe("iso8601");
+    });
+
+    test("with time zone", () => {
+        const timeZone = new Temporal.TimeZone("UTC");
+        const zonedDateTime = Temporal.Now.zonedDateTimeISO(timeZone);
+        expect(zonedDateTime).toBeInstanceOf(Temporal.ZonedDateTime);
+        expect(zonedDateTime.calendar.id).toBe("iso8601");
+        expect(zonedDateTime.timeZone).toBe(timeZone);
+    });
+});