LibJS: Explicitly handle invalid Date objects in local time setters

This is a normative change in the ECMA-262 spec:
https://github.com/tc39/ecma262/commit/ca53334

Userland/Libraries/LibJS/Runtime/DatePrototype.cpp

@@ -378,31 +378,47 @@ static ThrowCompletionOr<Value> argument_or_value(GlobalObject& global_object, s
     return Value(fallback);
 }
 
+static ThrowCompletionOr<Optional<Value>> argument_or_empty(GlobalObject& global_object, size_t index)
+{
+    auto& vm = global_object.vm();
+
+    if (vm.argument_count() > index)
+        return TRY(vm.argument(index).to_number(global_object));
+
+    return Optional<Value> {};
+}
+
 // 21.4.4.20 Date.prototype.setDate ( date ), https://tc39.es/ecma262/#sec-date.prototype.setdate
 JS_DEFINE_NATIVE_FUNCTION(DatePrototype::set_date)
 {
-    // 1. Let t be LocalTime(? thisTimeValue(this value)).
+    // 1. Let t be ? thisTimeValue(this value).
     auto this_time = TRY(this_time_value(global_object, vm.this_value(global_object)));
-    auto time = local_time(this_time.as_double());
 
     // 2. Let dt be ? ToNumber(date).
     auto date = TRY(vm.argument(0).to_number(global_object));
 
-    // 3. Let newDate be MakeDate(MakeDay(YearFromTime(t), MonthFromTime(t), dt), TimeWithinDay(t)).
+    // 3. If t is NaN, return NaN.
+    if (this_time.is_nan())
+        return js_nan();
+
+    // 4. Set t to LocalTime(t).
+    auto time = local_time(this_time.as_double());
+
+    // 5. Let newDate be MakeDate(MakeDay(YearFromTime(t), MonthFromTime(t), dt), TimeWithinDay(t)).
     auto year = Value(year_from_time(time));
     auto month = Value(month_from_time(time));
 
     auto day = make_day(global_object, year, month, date);
     auto new_date = make_date(day, Value(time_within_day(time)));
 
-    // 4. Let u be TimeClip(UTC(newDate)).
+    // 6. Let u be TimeClip(UTC(newDate)).
     new_date = time_clip(global_object, Value(utc_time(new_date.as_double())));
 
-    // 5. Set the [[DateValue]] internal slot of this Date object to u.
+    // 7. Set the [[DateValue]] internal slot of this Date object to u.
     auto* this_object = MUST(typed_this_object(global_object));
     this_object->set_date_value(new_date.as_double());
 
-    // 6. Return u.
+    // 8. Return u.
     return new_date;
 }
 
@@ -412,14 +428,14 @@ JS_DEFINE_NATIVE_FUNCTION(DatePrototype::set_full_year)
     // 1. Let t be ? thisTimeValue(this value).
     auto this_time = TRY(this_time_value(global_object, vm.this_value(global_object)));
 
-    // 2. If t is NaN, set t to +0𝔽; otherwise, set t to LocalTime(t).
+    // 2. Let y be ? ToNumber(year).
+    auto year = TRY(vm.argument(0).to_number(global_object));
+
+    // 3. If t is NaN, set t to +0𝔽; otherwise, set t to LocalTime(t).
     double time = 0;
     if (!this_time.is_nan())
         time = local_time(this_time.as_double());
 
-    // 3. Let y be ? ToNumber(year).
-    auto year = TRY(vm.argument(0).to_number(global_object));
-
     // 4. If month is not present, let m be MonthFromTime(t); otherwise, let m be ? ToNumber(month).
     auto month = TRY(argument_or_value(global_object, 1, month_from_time(time)));
 
@@ -446,155 +462,213 @@ JS_DEFINE_NATIVE_FUNCTION(DatePrototype::set_hours)
 {
     // 1. Let t be LocalTime(? thisTimeValue(this value)).
     auto this_time = TRY(this_time_value(global_object, vm.this_value(global_object)));
-    auto time = local_time(this_time.as_double());
 
     // 2. Let h be ? ToNumber(hour).
     auto hour = TRY(vm.argument(0).to_number(global_object));
 
-    // 3. If min is not present, let m be MinFromTime(t); otherwise, let m be ? ToNumber(min).
-    auto minute = TRY(argument_or_value(global_object, 1, min_from_time(time)));
+    // 3. If min is present, let m be ? ToNumber(min).
+    auto minute = TRY(argument_or_empty(global_object, 1));
 
-    // 4. If sec is not present, let s be SecFromTime(t); otherwise, let s be ? ToNumber(sec).
-    auto second = TRY(argument_or_value(global_object, 2, sec_from_time(time)));
+    // 4. If sec is present, let s be ? ToNumber(sec).
+    auto second = TRY(argument_or_empty(global_object, 2));
 
-    // 5. If ms is not present, let milli be msFromTime(t); otherwise, let milli be ? ToNumber(ms).
-    auto millisecond = TRY(argument_or_value(global_object, 3, ms_from_time(time)));
+    // 5. If ms is present, let milli be ? ToNumber(ms).
+    auto millisecond = TRY(argument_or_empty(global_object, 3));
 
-    // 6. Let date be MakeDate(Day(t), MakeTime(h, m, s, milli)).
-    auto new_time = make_time(global_object, hour, minute, second, millisecond);
+    // 6. If t is NaN, return NaN.
+    if (this_time.is_nan())
+        return js_nan();
+
+    // 7. Set t to LocalTime(t).
+    auto time = local_time(this_time.as_double());
+
+    // 8. If min is not present, let m be MinFromTime(t).
+    if (!minute.has_value())
+        minute = Value(min_from_time(time));
+
+    // 9. If sec is not present, let s be SecFromTime(t).
+    if (!second.has_value())
+        second = Value(sec_from_time(time));
+
+    // 10. If ms is not present, let milli be msFromTime(t).
+    if (!millisecond.has_value())
+        millisecond = Value(ms_from_time(time));
+
+    // 11. Let date be MakeDate(Day(t), MakeTime(h, m, s, milli)).
+    auto new_time = make_time(global_object, hour, *minute, *second, *millisecond);
     auto date = make_date(Value(day(time)), new_time);
 
-    // 7. Let u be TimeClip(UTC(date)).
+    // 12. Let u be TimeClip(UTC(date)).
     date = time_clip(global_object, Value(utc_time(date.as_double())));
 
-    // 8. Set the [[DateValue]] internal slot of this Date object to u.
+    // 13. Set the [[DateValue]] internal slot of this Date object to u.
     auto* this_object = MUST(typed_this_object(global_object));
     this_object->set_date_value(date.as_double());
 
-    // 9. Return u.
+    // 14. Return u.
     return date;
 }
 
 // 21.4.4.23 Date.prototype.setMilliseconds ( ms ), https://tc39.es/ecma262/#sec-date.prototype.setmilliseconds
 JS_DEFINE_NATIVE_FUNCTION(DatePrototype::set_milliseconds)
 {
-    // 1. Let t be LocalTime(? thisTimeValue(this value)).
+    // 1. Let t be ? thisTimeValue(this value).
     auto this_time = TRY(this_time_value(global_object, vm.this_value(global_object)));
-    auto time = local_time(this_time.as_double());
 
     // 2. Set ms to ? ToNumber(ms).
     auto millisecond = TRY(vm.argument(0).to_number(global_object));
 
-    // 3. Let time be MakeTime(HourFromTime(t), MinFromTime(t), SecFromTime(t), ms).
+    // 3. If t is NaN, return NaN.
+    if (this_time.is_nan())
+        return js_nan();
+
+    // 4. Set t to LocalTime(t).
+    auto time = local_time(this_time.as_double());
+
+    // 5. Let time be MakeTime(HourFromTime(t), MinFromTime(t), SecFromTime(t), ms).
     auto hour = Value(hour_from_time(time));
     auto minute = Value(min_from_time(time));
     auto second = Value(sec_from_time(time));
 
     auto new_time = make_time(global_object, hour, minute, second, millisecond);
 
-    // 4. Let u be TimeClip(UTC(MakeDate(Day(t), time))).
+    // 6. Let u be TimeClip(UTC(MakeDate(Day(t), time))).
     auto date = make_date(Value(day(time)), new_time);
     date = time_clip(global_object, Value(utc_time(date.as_double())));
 
-    // 5. Set the [[DateValue]] internal slot of this Date object to u.
+    // 7. Set the [[DateValue]] internal slot of this Date object to u.
     auto* this_object = MUST(typed_this_object(global_object));
     this_object->set_date_value(date.as_double());
 
-    // 6. Return u.
+    // 8. Return u.
     return date;
 }
 
 // 21.4.4.24 Date.prototype.setMinutes ( min [ , sec [ , ms ] ] ), https://tc39.es/ecma262/#sec-date.prototype.setminutes
 JS_DEFINE_NATIVE_FUNCTION(DatePrototype::set_minutes)
 {
-    // 1. Let t be LocalTime(? thisTimeValue(this value)).
+    // 1. Let t be ? thisTimeValue(this value).
     auto this_time = TRY(this_time_value(global_object, vm.this_value(global_object)));
-    auto time = local_time(this_time.as_double());
 
     // 2. Let m be ? ToNumber(min).
     auto minute = TRY(vm.argument(0).to_number(global_object));
 
-    // 3. If sec is not present, let s be SecFromTime(t); otherwise, let s be ? ToNumber(sec).
-    auto second = TRY(argument_or_value(global_object, 1, sec_from_time(time)));
+    // 3. If sec is present, let s be ? ToNumber(sec).
+    auto second = TRY(argument_or_empty(global_object, 1));
 
-    // 4. If ms is not present, let milli be msFromTime(t); otherwise, let milli be ? ToNumber(ms).
-    auto millisecond = TRY(argument_or_value(global_object, 2, ms_from_time(time)));
+    // 4. If ms is present, let milli be ? ToNumber(ms).
+    auto millisecond = TRY(argument_or_empty(global_object, 2));
+
+    // 5. If t is NaN, return NaN.
+    if (this_time.is_nan())
+        return js_nan();
+
+    // 6. Set t to LocalTime(t).
+    auto time = local_time(this_time.as_double());
+
+    // 7. If sec is not present, let s be SecFromTime(t).
+    if (!second.has_value())
+        second = Value(sec_from_time(time));
+
+    // 8. If ms is not present, let milli be msFromTime(t).
+    if (!millisecond.has_value())
+        millisecond = Value(ms_from_time(time));
 
-    // 5. Let date be MakeDate(Day(t), MakeTime(HourFromTime(t), m, s, milli)).
+    // 9. Let date be MakeDate(Day(t), MakeTime(HourFromTime(t), m, s, milli)).
     auto hour = Value(hour_from_time(time));
 
-    auto new_time = make_time(global_object, hour, minute, second, millisecond);
+    auto new_time = make_time(global_object, hour, minute, *second, *millisecond);
     auto date = make_date(Value(day(time)), new_time);
 
-    // 6. Let u be TimeClip(UTC(date)).
+    // 10. Let u be TimeClip(UTC(date)).
     date = time_clip(global_object, Value(utc_time(date.as_double())));
 
-    // 7. Set the [[DateValue]] internal slot of this Date object to u.
+    // 11. Set the [[DateValue]] internal slot of this Date object to u.
     auto* this_object = MUST(typed_this_object(global_object));
     this_object->set_date_value(date.as_double());
 
-    // 8. Return u.
+    // 12. Return u.
     return date;
 }
 
 // 21.4.4.25 Date.prototype.setMonth ( month [ , date ] ), https://tc39.es/ecma262/#sec-date.prototype.setmonth
 JS_DEFINE_NATIVE_FUNCTION(DatePrototype::set_month)
 {
-    // 1. Let t be LocalTime(? thisTimeValue(this value)).
+    // 1. Let t be ? thisTimeValue(this value).
     auto this_time = TRY(this_time_value(global_object, vm.this_value(global_object)));
-    auto time = local_time(this_time.as_double());
 
     // 2. Let m be ? ToNumber(month).
     auto month = TRY(vm.argument(0).to_number(global_object));
 
-    // 3. If date is not present, let dt be DateFromTime(t); otherwise, let dt be ? ToNumber(date).
-    auto date = TRY(argument_or_value(global_object, 1, date_from_time(time)));
+    // 3. If date is present, let dt be ? ToNumber(date).
+    auto date = TRY(argument_or_empty(global_object, 1));
 
-    // 4. Let newDate be MakeDate(MakeDay(YearFromTime(t), m, dt), TimeWithinDay(t)).
+    // 4. If t is NaN, return NaN.
+    if (this_time.is_nan())
+        return js_nan();
+
+    // 5. Set t to LocalTime(t).
+    auto time = local_time(this_time.as_double());
+
+    // 6. If date is not present, let dt be DateFromTime(t).
+    if (!date.has_value())
+        date = Value(date_from_time(time));
+
+    // 7. Let newDate be MakeDate(MakeDay(YearFromTime(t), m, dt), TimeWithinDay(t)).
     auto year = Value(year_from_time(time));
 
-    auto day = make_day(global_object, year, month, date);
+    auto day = make_day(global_object, year, month, *date);
     auto new_date = make_date(day, Value(time_within_day(time)));
 
-    // 5. Let u be TimeClip(UTC(newDate)).
+    // 8. Let u be TimeClip(UTC(newDate)).
     new_date = time_clip(global_object, Value(utc_time(new_date.as_double())));
 
-    // 6. Set the [[DateValue]] internal slot of this Date object to u.
+    // 9. Set the [[DateValue]] internal slot of this Date object to u.
     auto* this_object = MUST(typed_this_object(global_object));
     this_object->set_date_value(new_date.as_double());
 
-    // 7. Return u.
+    // 10. Return u.
     return new_date;
 }
 
 // 21.4.4.26 Date.prototype.setSeconds ( sec [ , ms ] ), https://tc39.es/ecma262/#sec-date.prototype.setseconds
 JS_DEFINE_NATIVE_FUNCTION(DatePrototype::set_seconds)
 {
-    // 1. Let t be LocalTime(? thisTimeValue(this value)).
+    // 1. Let t be ? thisTimeValue(this value).
     auto this_time = TRY(this_time_value(global_object, vm.this_value(global_object)));
-    auto time = local_time(this_time.as_double());
 
     // 2. Let s be ? ToNumber(sec).
     auto second = TRY(vm.argument(0).to_number(global_object));
 
-    // 3. If ms is not present, let milli be msFromTime(t); otherwise, let milli be ? ToNumber(ms).
-    auto millisecond = TRY(argument_or_value(global_object, 1, ms_from_time(time)));
+    // 3. If ms is present, let milli be ? ToNumber(ms).
+    auto millisecond = TRY(argument_or_empty(global_object, 1));
+
+    // 4. If t is NaN, return NaN.
+    if (this_time.is_nan())
+        return js_nan();
+
+    // 5. Set t to LocalTime(t).
+    auto time = local_time(this_time.as_double());
 
-    // 4. Let date be MakeDate(Day(t), MakeTime(HourFromTime(t), MinFromTime(t), s, milli)).
+    // 6. If ms is not present, let milli be msFromTime(t).
+    if (!millisecond.has_value())
+        millisecond = Value(ms_from_time(time));
+
+    // 7. Let date be MakeDate(Day(t), MakeTime(HourFromTime(t), MinFromTime(t), s, milli)).
     auto hour = Value(hour_from_time(time));
     auto minute = Value(min_from_time(time));
 
-    auto new_time = make_time(global_object, hour, minute, second, millisecond);
+    auto new_time = make_time(global_object, hour, minute, second, *millisecond);
     auto new_date = make_date(Value(day(time)), new_time);
 
-    // 5. Let u be TimeClip(UTC(date)).
+    // 8. Let u be TimeClip(UTC(date)).
     new_date = time_clip(global_object, Value(utc_time(new_date.as_double())));
 
-    // 6. Set the [[DateValue]] internal slot of this Date object to u.
+    // 9. Set the [[DateValue]] internal slot of this Date object to u.
     auto* this_object = MUST(typed_this_object(global_object));
     this_object->set_date_value(new_date.as_double());
 
-    // 7. Return u.
+    // 10. Return u.
     return new_date;
 }
 

Userland/Libraries/LibJS/Tests/builtins/Date/Date.prototype.setDate.js

@@ -30,3 +30,9 @@ test("Day as argument", () => {
     expect(date.getSeconds()).toBe(0);
     expect(date.getMilliseconds()).toBe(0);
 });
+
+test("invalid date", () => {
+    let date = new Date(NaN);
+    expect(date.setDate(15)).toBeNaN();
+    expect(date.getDate()).toBeNaN();
+});

Userland/Libraries/LibJS/Tests/builtins/Date/Date.prototype.setFullYear.js

@@ -110,3 +110,9 @@ test("Make Invalid Date valid again", () => {
     expect(date.getSeconds()).toBe(0);
     expect(date.getMilliseconds()).toBe(0);
 });
+
+test("invalid date", () => {
+    let date = new Date(NaN);
+    date.setFullYear(2022);
+    expect(date.getFullYear()).toBe(2022);
+});

Userland/Libraries/LibJS/Tests/builtins/Date/Date.prototype.setHours.js

@@ -25,3 +25,9 @@ test("basic functionality", () => {
     d.setHours("a");
     expect(d.getHours()).toBe(NaN);
 });
+
+test("invalid date", () => {
+    let date = new Date(NaN);
+    expect(date.setHours(2)).toBeNaN();
+    expect(date.getHours()).toBeNaN();
+});

Userland/Libraries/LibJS/Tests/builtins/Date/Date.prototype.setMilliseconds.js

@@ -10,3 +10,9 @@ test("basic functionality", () => {
     d.setMilliseconds("a");
     expect(d.getMilliseconds()).toBe(NaN);
 });
+
+test("invalid date", () => {
+    let date = new Date(NaN);
+    expect(date.setMilliseconds(2)).toBeNaN();
+    expect(date.getMilliseconds()).toBeNaN();
+});

Userland/Libraries/LibJS/Tests/builtins/Date/Date.prototype.setMinutes.js

@@ -19,3 +19,9 @@ test("basic functionality", () => {
     d.setMinutes("a");
     expect(d.getMinutes()).toBe(NaN);
 });
+
+test("invalid date", () => {
+    let date = new Date(NaN);
+    expect(date.setMinutes(2)).toBeNaN();
+    expect(date.getMinutes()).toBeNaN();
+});

Userland/Libraries/LibJS/Tests/builtins/Date/Date.prototype.setMonth.js

@@ -61,3 +61,9 @@ test("NaN or undefined in any arguments", () => {
     date.setMonth(2021, undefined);
     expect(date.getTime()).toBe(NaN);
 });
+
+test("invalid date", () => {
+    let date = new Date(NaN);
+    expect(date.setMonth(2)).toBeNaN();
+    expect(date.getMonth()).toBeNaN();
+});

Userland/Libraries/LibJS/Tests/builtins/Date/Date.prototype.setSeconds.js

@@ -14,3 +14,9 @@ test("basic functionality", () => {
     d.setSeconds("a");
     expect(d.getSeconds()).toBe(NaN);
 });
+
+test("invalid date", () => {
+    let date = new Date(NaN);
+    expect(date.setSeconds(2)).toBeNaN();
+    expect(date.getSeconds()).toBeNaN();
+});

Userland/Libraries/LibJS/Tests/builtins/Date/Date.prototype.setTime.js

@@ -45,3 +45,9 @@ test("Make Invalid Date valid again", () => {
     expect(date.getUTCSeconds()).toBe(46);
     expect(date.getUTCMilliseconds()).toBe(0);
 });
+
+test("invalid date", () => {
+    let date = new Date(NaN);
+    expect(date.setTime(1622993746000)).toBe(1622993746000);
+    expect(date.getTime()).toBe(1622993746000);
+});