LibJS: Implement Temporal.PlainDateTime.prototype.add/subtract/equals

Author: https://github.com/trflynn89
Commit: https://github.com/LadybirdBrowser/ladybird/commit/85ffacacde1
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/2544

Libraries/LibJS/Runtime/Temporal/PlainDateTime.cpp

@@ -367,4 +367,39 @@ ThrowCompletionOr<Crypto::BigFraction> difference_plain_date_time_with_total(VM&
     return TRY(total_relative_duration(vm, diff, dest_epoch_ns, iso_date_time1, {}, calendar, unit));
 }
 
+// 5.5.16 AddDurationToDateTime ( operation, dateTime, temporalDurationLike, options ), https://tc39.es/proposal-temporal/#sec-temporal-adddurationtodatetime
+ThrowCompletionOr<GC::Ref<PlainDateTime>> add_duration_to_date_time(VM& vm, ArithmeticOperation operation, PlainDateTime const& date_time, Value temporal_duration_like, Value options)
+{
+    // 1. Let duration be ? ToTemporalDuration(temporalDurationLike).
+    auto duration = TRY(to_temporal_duration(vm, temporal_duration_like));
+
+    // 2. If operation is SUBTRACT, set duration to CreateNegatedTemporalDuration(duration).
+    if (operation == ArithmeticOperation::Subtract)
+        duration = create_negated_temporal_duration(vm, duration);
+
+    // 3. Let resolvedOptions be ? GetOptionsObject(options).
+    auto resolved_options = TRY(get_options_object(vm, options));
+
+    // 4. Let overflow be ? GetTemporalOverflowOption(resolvedOptions).
+    auto overflow = TRY(get_temporal_overflow_option(vm, resolved_options));
+
+    // 5. Let internalDuration be ToInternalDurationRecordWith24HourDays(duration).
+    auto internal_duration = to_internal_duration_record_with_24_hour_days(vm, duration);
+
+    // 6. Let timeResult be AddTime(dateTime.[[ISODateTime]].[[Time]], internalDuration.[[Time]]).
+    auto time_result = add_time(date_time.iso_date_time().time, internal_duration.time);
+
+    // 7. Let dateDuration be ? AdjustDateDurationRecord(internalDuration.[[Date]], timeResult.[[Days]]).
+    auto date_duration = TRY(adjust_date_duration_record(vm, internal_duration.date, time_result.days));
+
+    // 8. Let addedDate be ? CalendarDateAdd(dateTime.[[Calendar]], dateTime.[[ISODateTime]].[[ISODate]], dateDuration, overflow).
+    auto added_date = TRY(calendar_date_add(vm, date_time.calendar(), date_time.iso_date_time().iso_date, date_duration, overflow));
+
+    // 9. Let result be CombineISODateAndTimeRecord(addedDate, timeResult).
+    auto result = combine_iso_date_and_time_record(added_date, time_result);
+
+    // 10. Return ? CreateTemporalDateTime(result, dateTime.[[Calendar]]).
+    return TRY(create_temporal_date_time(vm, result, date_time.calendar()));
+}
+
 }

Libraries/LibJS/Runtime/Temporal/PlainDateTime.h

@@ -44,5 +44,6 @@ ISODateTime round_iso_date_time(ISODateTime const&, u64 increment, Unit, Roundin
 ThrowCompletionOr<InternalDuration> difference_iso_date_time(VM&, ISODateTime const&, ISODateTime const&, StringView calendar, Unit largest_unit);
 ThrowCompletionOr<InternalDuration> difference_plain_date_time_with_rounding(VM&, ISODateTime const&, ISODateTime const&, StringView calendar, Unit largest_unit, u64 rounding_increment, Unit smallest_unit, RoundingMode);
 ThrowCompletionOr<Crypto::BigFraction> difference_plain_date_time_with_total(VM&, ISODateTime const&, ISODateTime const&, StringView calendar, Unit);
+ThrowCompletionOr<GC::Ref<PlainDateTime>> add_duration_to_date_time(VM&, ArithmeticOperation, PlainDateTime const&, Value temporal_duration_like, Value options);
 
 }

Libraries/LibJS/Runtime/Temporal/PlainDateTimePrototype.cpp

@@ -53,6 +53,9 @@ void PlainDateTimePrototype::initialize(Realm& realm)
     define_native_accessor(realm, vm.names.inLeapYear, in_leap_year_getter, {}, Attribute::Configurable);
 
     u8 attr = Attribute::Writable | Attribute::Configurable;
+    define_native_function(realm, vm.names.add, add, 1, attr);
+    define_native_function(realm, vm.names.subtract, subtract, 1, attr);
+    define_native_function(realm, vm.names.equals, equals, 1, attr);
     define_native_function(realm, vm.names.toString, to_string, 0, attr);
     define_native_function(realm, vm.names.toLocaleString, to_locale_string, 0, attr);
     define_native_function(realm, vm.names.toJSON, to_json, 0, attr);
@@ -213,6 +216,52 @@ JS_DEFINE_NATIVE_FUNCTION(PlainDateTimePrototype::year_of_week_getter)
     return *result;
 }
 
+// 5.3.28 Temporal.PlainDateTime.prototype.add ( temporalDurationLike [ , options ] ), https://tc39.es/proposal-temporal/#sec-temporal.plaindatetime.prototype.add
+JS_DEFINE_NATIVE_FUNCTION(PlainDateTimePrototype::add)
+{
+    auto temporal_duration_like = vm.argument(0);
+    auto options = vm.argument(1);
+
+    // 1. Let dateTime be the this value.
+    // 2. Perform ? RequireInternalSlot(dateTime, [[InitializedTemporalDateTime]]).
+    auto date_time = TRY(typed_this_object(vm));
+
+    // 3. Return ? AddDurationToDateTime(ADD, dateTime, temporalDurationLike, options).
+    return TRY(add_duration_to_date_time(vm, ArithmeticOperation::Add, date_time, temporal_duration_like, options));
+}
+
+// 5.3.29 Temporal.PlainDateTime.prototype.subtract ( temporalDurationLike [ , options ] ), https://tc39.es/proposal-temporal/#sec-temporal.plaindatetime.prototype.add
+JS_DEFINE_NATIVE_FUNCTION(PlainDateTimePrototype::subtract)
+{
+    auto temporal_duration_like = vm.argument(0);
+    auto options = vm.argument(1);
+
+    // 1. Let dateTime be the this value.
+    // 2. Perform ? RequireInternalSlot(dateTime, [[InitializedTemporalDateTime]]).
+    auto date_time = TRY(typed_this_object(vm));
+
+    // 3. Return ? AddDurationToDateTime(SUBTRACT, dateTime, temporalDurationLike, options).
+    return TRY(add_duration_to_date_time(vm, ArithmeticOperation::Subtract, date_time, temporal_duration_like, options));
+}
+
+// 5.3.33 Temporal.PlainDateTime.prototype.equals ( other ), https://tc39.es/proposal-temporal/#sec-temporal.plaindatetime.prototype.equals
+JS_DEFINE_NATIVE_FUNCTION(PlainDateTimePrototype::equals)
+{
+    // 1. Let dateTime be the this value.
+    // 2. Perform ? RequireInternalSlot(dateTime, [[InitializedTemporalDateTime]]).
+    auto date_time = TRY(typed_this_object(vm));
+
+    // 3. Set other to ? ToTemporalDateTime(other).
+    auto other = TRY(to_temporal_date_time(vm, vm.argument(0)));
+
+    // 4. If CompareISODateTime(dateTime.[[ISODateTime]], other.[[ISODateTime]]) ≠ 0, return false.
+    if (compare_iso_date_time(date_time->iso_date_time(), other->iso_date_time()) != 0)
+        return false;
+
+    // 5. Return CalendarEquals(dateTime.[[Calendar]], other.[[Calendar]]).
+    return calendar_equals(date_time->calendar(), other->calendar());
+}
+
 // 5.3.34 Temporal.PlainDateTime.prototype.toString ( [ options ] ), https://tc39.es/proposal-temporal/#sec-temporal.plaindatetime.prototype.tostring
 JS_DEFINE_NATIVE_FUNCTION(PlainDateTimePrototype::to_string)
 {

Libraries/LibJS/Runtime/Temporal/PlainDateTimePrototype.h

@@ -45,6 +45,9 @@ private:
     JS_DECLARE_NATIVE_FUNCTION(days_in_year_getter);
     JS_DECLARE_NATIVE_FUNCTION(months_in_year_getter);
     JS_DECLARE_NATIVE_FUNCTION(in_leap_year_getter);
+    JS_DECLARE_NATIVE_FUNCTION(add);
+    JS_DECLARE_NATIVE_FUNCTION(subtract);
+    JS_DECLARE_NATIVE_FUNCTION(equals);
     JS_DECLARE_NATIVE_FUNCTION(to_string);
     JS_DECLARE_NATIVE_FUNCTION(to_locale_string);
     JS_DECLARE_NATIVE_FUNCTION(to_json);

Libraries/LibJS/Tests/builtins/Temporal/PlainDateTime/PlainDateTime.prototype.add.js

@@ -0,0 +1,19 @@
+describe("correct behavior", () => {
+    test("length is 1", () => {
+        expect(Temporal.PlainDateTime.prototype.add).toHaveLength(1);
+    });
+
+    test("basic functionality", () => {
+        const plainDateTime = new Temporal.PlainDateTime(1970, 1, 1);
+        const result = plainDateTime.add(new Temporal.Duration(51, 6, 0, 5, 18, 14, 47));
+        expect(result.equals(new Temporal.PlainDateTime(2021, 7, 6, 18, 14, 47))).toBeTrue();
+    });
+});
+
+describe("errors", () => {
+    test("this value must be a Temporal.PlainDateTime object", () => {
+        expect(() => {
+            Temporal.PlainDateTime.prototype.add.call("foo");
+        }).toThrowWithMessage(TypeError, "Not an object of type Temporal.PlainDateTime");
+    });
+});

Libraries/LibJS/Tests/builtins/Temporal/PlainDateTime/PlainDateTime.prototype.equals.js

@@ -0,0 +1,13 @@
+describe("correct behavior", () => {
+    test("length is 1", () => {
+        expect(Temporal.PlainDateTime.prototype.equals).toHaveLength(1);
+    });
+
+    test("basic functionality", () => {
+        const calendar = "gregory";
+        const firstPlainDateTime = new Temporal.PlainDateTime(1, 1, 1, 1, 1, 1, 1, 1, 1, calendar);
+        const secondPlainDateTime = new Temporal.PlainDateTime(0, 1, 1, 1, 1, 1, 1, 1, 1, calendar);
+        expect(firstPlainDateTime.equals(firstPlainDateTime));
+        expect(!firstPlainDateTime.equals(secondPlainDateTime));
+    });
+});

Libraries/LibJS/Tests/builtins/Temporal/PlainDateTime/PlainDateTime.prototype.subtract.js

@@ -0,0 +1,19 @@
+describe("correct behavior", () => {
+    test("length is 1", () => {
+        expect(Temporal.PlainDateTime.prototype.subtract).toHaveLength(1);
+    });
+
+    test("basic functionality", () => {
+        const plainDateTime = new Temporal.PlainDateTime(2021, 7, 6, 18, 14, 47);
+        const result = plainDateTime.subtract(new Temporal.Duration(51, 6, 0, 5, 18, 14, 47));
+        expect(result.equals(new Temporal.PlainDateTime(1970, 1, 1)));
+    });
+});
+
+describe("errors", () => {
+    test("this value must be a Temporal.PlainDateTime object", () => {
+        expect(() => {
+            Temporal.PlainDateTime.prototype.subtract.call("foo");
+        }).toThrowWithMessage(TypeError, "Not an object of type Temporal.PlainDateTime");
+    });
+});