LibJS: Implement Temporal.PlainDate.prototype.toPlainDateTime()

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

@@ -11,7 +11,9 @@
 #include <LibJS/Runtime/Temporal/Calendar.h>
 #include <LibJS/Runtime/Temporal/PlainDate.h>
 #include <LibJS/Runtime/Temporal/PlainDatePrototype.h>
+#include <LibJS/Runtime/Temporal/PlainDateTime.h>
 #include <LibJS/Runtime/Temporal/PlainMonthDay.h>
+#include <LibJS/Runtime/Temporal/PlainTime.h>
 #include <LibJS/Runtime/Temporal/PlainYearMonth.h>
 
 namespace JS::Temporal {
@@ -51,6 +53,7 @@ void PlainDatePrototype::initialize(GlobalObject& global_object)
     define_native_function(vm.names.getISOFields, get_iso_fields, 0, attr);
     define_native_function(vm.names.withCalendar, with_calendar, 1, attr);
     define_native_function(vm.names.equals, equals, 1, attr);
+    define_native_function(vm.names.toPlainDateTime, to_plain_date_time, 0, attr);
     define_native_function(vm.names.toString, to_string, 0, attr);
     define_native_function(vm.names.toLocaleString, to_locale_string, 0, attr);
     define_native_function(vm.names.toJSON, to_json, 0, attr);
@@ -400,6 +403,30 @@ JS_DEFINE_NATIVE_FUNCTION(PlainDatePrototype::equals)
     return Value(calendar_equals(global_object, temporal_date->calendar(), other->calendar()));
 }
 
+// 3.3.26 Temporal.PlainDate.prototype.toPlainDateTime ( [ temporalTime ] ), https://tc39.es/proposal-temporal/#sec-temporal.plaindate.prototype.toplaindatetime
+JS_DEFINE_NATIVE_FUNCTION(PlainDatePrototype::to_plain_date_time)
+{
+    // 1. Let temporalDate be the this value.
+    // 2. Perform ? RequireInternalSlot(temporalDate, [[InitializedTemporalDate]]).
+    auto* temporal_date = typed_this(global_object);
+    if (vm.exception())
+        return {};
+
+    // 3. If temporalTime is undefined, then
+    if (vm.argument(0).is_undefined()) {
+        // a. Return ? CreateTemporalDateTime(temporalDate.[[ISOYear]], temporalDate.[[ISOMonth]], temporalDate.[[ISODay]], 0, 0, 0, 0, 0, 0, temporalDate.[[Calendar]]).
+        return create_temporal_date_time(global_object, temporal_date->iso_year(), temporal_date->iso_month(), temporal_date->iso_day(), 0, 0, 0, 0, 0, 0, temporal_date->calendar());
+    }
+
+    // 4. Set temporalTime to ? ToTemporalTime(temporalTime).
+    auto* temporal_time = to_temporal_time(global_object, vm.argument(0));
+    if (vm.exception())
+        return {};
+
+    // 5. Return ? CreateTemporalDateTime(temporalDate.[[ISOYear]], temporalDate.[[ISOMonth]], temporalDate.[[ISODay]], temporalTime.[[ISOHour]], temporalTime.[[ISOMinute]], temporalTime.[[ISOSecond]], temporalTime.[[ISOMillisecond]], temporalTime.[[ISOMicrosecond]], temporalTime.[[ISONanosecond]], temporalDate.[[Calendar]]).
+    return create_temporal_date_time(global_object, temporal_date->iso_year(), temporal_date->iso_month(), temporal_date->iso_day(), temporal_time->iso_hour(), temporal_time->iso_minute(), temporal_time->iso_second(), temporal_time->iso_millisecond(), temporal_time->iso_microsecond(), temporal_time->iso_nanosecond(), temporal_date->calendar());
+}
+
 // 3.3.28 Temporal.PlainDate.prototype.toString ( [ options ] ), https://tc39.es/proposal-temporal/#sec-temporal.plaindate.prototype.tostring
 JS_DEFINE_NATIVE_FUNCTION(PlainDatePrototype::to_string)
 {

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

@@ -37,6 +37,7 @@ private:
     JS_DECLARE_NATIVE_FUNCTION(get_iso_fields);
     JS_DECLARE_NATIVE_FUNCTION(with_calendar);
     JS_DECLARE_NATIVE_FUNCTION(equals);
+    JS_DECLARE_NATIVE_FUNCTION(to_plain_date_time);
     JS_DECLARE_NATIVE_FUNCTION(to_string);
     JS_DECLARE_NATIVE_FUNCTION(to_locale_string);
     JS_DECLARE_NATIVE_FUNCTION(to_json);

Userland/Libraries/LibJS/Tests/builtins/Temporal/PlainDate/PlainDate.prototype.toPlainDateTime.js

@@ -0,0 +1,20 @@
+describe("correct behavior", () => {
+    test("length is 0", () => {
+        expect(Temporal.PlainDate.prototype.toPlainDateTime).toHaveLength(0);
+    });
+
+    test("basic functionality", () => {
+        const plainDate = new Temporal.PlainDate(2021, 8, 27);
+        const plainTime = new Temporal.PlainTime(18, 11, 44, 1, 2, 3);
+        const plainDateTime = plainDate.toPlainDateTime(plainTime);
+        expect(plainDateTime.year).toBe(2021);
+        expect(plainDateTime.month).toBe(8);
+        expect(plainDateTime.day).toBe(27);
+        expect(plainDateTime.hour).toBe(18);
+        expect(plainDateTime.minute).toBe(11);
+        expect(plainDateTime.second).toBe(44);
+        expect(plainDateTime.millisecond).toBe(1);
+        expect(plainDateTime.microsecond).toBe(2);
+        expect(plainDateTime.nanosecond).toBe(3);
+    });
+});