LibJS: Remove IsISOLeapYear

This is an editorial change in the Temporal spec.

See: https://github.com/tc39/proposal-temporal/commit/a36bdd4

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

@@ -597,28 +597,7 @@ ThrowCompletionOr<Object*> consolidate_calendars(GlobalObject& global_object, Ob
     return vm.throw_completion<RangeError>(global_object, ErrorType::TemporalInvalidCalendar);
 }
 
-// 12.2.29 IsISOLeapYear ( year ), https://tc39.es/proposal-temporal/#sec-temporal-isisoleapyear
-bool is_iso_leap_year(i32 year)
-{
-    // 1. Assert: year is an integer.
-
-    // 2. If year modulo 4 ≠ 0, return false.
-    if (year % 4 != 0)
-        return false;
-
-    // 3. If year modulo 400 = 0, return true.
-    if (year % 400 == 0)
-        return true;
-
-    // 4. If year modulo 100 = 0, return false.
-    if (year % 100 == 0)
-        return false;
-
-    // 5. Return true.
-    return true;
-}
-
-// 12.2.30 ISODaysInMonth ( year, month ), https://tc39.es/proposal-temporal/#sec-temporal-isodaysinmonth
+// 12.2.29 ISODaysInMonth ( year, month ), https://tc39.es/proposal-temporal/#sec-temporal-isodaysinmonth
 u8 iso_days_in_month(i32 year, u8 month)
 {
     // 1. Assert: year is an integer.
@@ -634,15 +613,11 @@ u8 iso_days_in_month(i32 year, u8 month)
     if (month == 4 || month == 6 || month == 9 || month == 11)
         return 30;
 
-    // 5. If ! IsISOLeapYear(year) is true, return 29.
-    if (is_iso_leap_year(year))
-        return 29;
-
-    // 6. Return 28.
-    return 28;
+    // 5. Return 28 + ℝ(InLeapYear(TimeFromYear(𝔽(year)))).
+    return 28 + JS::in_leap_year(time_from_year(year));
 }
 
-// 12.2.31 ToISODayOfWeek ( year, month, day ), https://tc39.es/proposal-temporal/#sec-temporal-toisodayofweek
+// 12.2.30 ToISODayOfWeek ( year, month, day ), https://tc39.es/proposal-temporal/#sec-temporal-toisodayofweek
 u8 to_iso_day_of_week(i32 year, u8 month, u8 day)
 {
     // 1. Assert: year is an integer.
@@ -662,7 +637,7 @@ u8 to_iso_day_of_week(i32 year, u8 month, u8 day)
     return day_of_week == 0 ? 7 : day_of_week;
 }
 
-// 12.2.32 ToISODayOfYear ( year, month, day ), https://tc39.es/proposal-temporal/#sec-temporal-toisodayofyear
+// 12.2.31 ToISODayOfYear ( year, month, day ), https://tc39.es/proposal-temporal/#sec-temporal-toisodayofyear
 u16 to_iso_day_of_year(i32 year, u8 month, u8 day)
 {
     // 1. Assert: year is an integer.
@@ -677,7 +652,7 @@ u16 to_iso_day_of_year(i32 year, u8 month, u8 day)
     return days;
 }
 
-// 12.2.33 ToISOWeekOfYear ( year, month, day ), https://tc39.es/proposal-temporal/#sec-temporal-toisoweekofyear
+// 12.2.32 ToISOWeekOfYear ( year, month, day ), https://tc39.es/proposal-temporal/#sec-temporal-toisoweekofyear
 u8 to_iso_week_of_year(i32 year, u8 month, u8 day)
 {
     // 1. Assert: year is an integer.
@@ -696,7 +671,7 @@ u8 to_iso_week_of_year(i32 year, u8 month, u8 day)
         // year is a leap year and ends with a Friday (i.e. the first day of the given year is a
         // Saturday, or day 6), it has 53 weeks, and 52 weeks otherwise.
         auto day_of_jump = to_iso_day_of_week(year, 1, 1);
-        if (day_of_jump == 5 || (is_iso_leap_year(year - 1) && day_of_jump == 6))
+        if (day_of_jump == 5 || (in_leap_year(time_from_year(year - 1)) && day_of_jump == 6))
             return 53;
         else
             return 52;
@@ -709,7 +684,7 @@ u8 to_iso_week_of_year(i32 year, u8 month, u8 day)
     return week;
 }
 
-// 12.2.34 BuildISOMonthCode ( month ), https://tc39.es/proposal-temporal/#sec-buildisomonthcode
+// 12.2.33 BuildISOMonthCode ( month ), https://tc39.es/proposal-temporal/#sec-buildisomonthcode
 String build_iso_month_code(u8 month)
 {
     // 1. Let numberPart be ToZeroPaddedDecimalString(month, 2).
@@ -717,7 +692,7 @@ String build_iso_month_code(u8 month)
     return String::formatted("M{:02}", month);
 }
 
-// 12.2.35 ResolveISOMonth ( fields ), https://tc39.es/proposal-temporal/#sec-temporal-resolveisomonth
+// 12.2.34 ResolveISOMonth ( fields ), https://tc39.es/proposal-temporal/#sec-temporal-resolveisomonth
 ThrowCompletionOr<double> resolve_iso_month(GlobalObject& global_object, Object const& fields)
 {
     auto& vm = global_object.vm();
@@ -777,7 +752,7 @@ ThrowCompletionOr<double> resolve_iso_month(GlobalObject& global_object, Object
     return number_part_integer;
 }
 
-// 12.2.36 ISODateFromFields ( fields, options ), https://tc39.es/proposal-temporal/#sec-temporal-isodatefromfields
+// 12.2.35 ISODateFromFields ( fields, options ), https://tc39.es/proposal-temporal/#sec-temporal-isodatefromfields
 ThrowCompletionOr<ISODate> iso_date_from_fields(GlobalObject& global_object, Object const& fields, Object const& options)
 {
     auto& vm = global_object.vm();
@@ -811,7 +786,7 @@ ThrowCompletionOr<ISODate> iso_date_from_fields(GlobalObject& global_object, Obj
     return regulate_iso_date(global_object, year.as_double(), month, day.as_double(), overflow);
 }
 
-// 12.2.37 ISOYearMonthFromFields ( fields, options ), https://tc39.es/proposal-temporal/#sec-temporal-isoyearmonthfromfields
+// 12.2.36 ISOYearMonthFromFields ( fields, options ), https://tc39.es/proposal-temporal/#sec-temporal-isoyearmonthfromfields
 ThrowCompletionOr<ISOYearMonth> iso_year_month_from_fields(GlobalObject& global_object, Object const& fields, Object const& options)
 {
     auto& vm = global_object.vm();
@@ -841,7 +816,7 @@ ThrowCompletionOr<ISOYearMonth> iso_year_month_from_fields(GlobalObject& global_
     return ISOYearMonth { .year = result.year, .month = result.month, .reference_iso_day = 1 };
 }
 
-// 12.2.38 ISOMonthDayFromFields ( fields, options ), https://tc39.es/proposal-temporal/#sec-temporal-isomonthdayfromfields
+// 12.2.37 ISOMonthDayFromFields ( fields, options ), https://tc39.es/proposal-temporal/#sec-temporal-isomonthdayfromfields
 ThrowCompletionOr<ISOMonthDay> iso_month_day_from_fields(GlobalObject& global_object, Object const& fields, Object const& options)
 {
     auto& vm = global_object.vm();
@@ -899,7 +874,7 @@ ThrowCompletionOr<ISOMonthDay> iso_month_day_from_fields(GlobalObject& global_ob
     return ISOMonthDay { .month = result->month, .day = result->day, .reference_iso_year = reference_iso_year };
 }
 
-// 12.2.39 ISOYear ( temporalObject ), https://tc39.es/proposal-temporal/#sec-temporal-isoyear
+// 12.2.38 ISOYear ( temporalObject ), https://tc39.es/proposal-temporal/#sec-temporal-isoyear
 i32 iso_year(Object& temporal_object)
 {
     // 1. Assert: temporalObject has an [[ISOYear]] internal slot.
@@ -917,7 +892,7 @@ i32 iso_year(Object& temporal_object)
     VERIFY_NOT_REACHED();
 }
 
-// 12.2.40 ISOMonth ( temporalObject ), https://tc39.es/proposal-temporal/#sec-temporal-isomonth
+// 12.2.39 ISOMonth ( temporalObject ), https://tc39.es/proposal-temporal/#sec-temporal-isomonth
 u8 iso_month(Object& temporal_object)
 {
     // 1. Assert: temporalObject has an [[ISOMonth]] internal slot.
@@ -935,7 +910,7 @@ u8 iso_month(Object& temporal_object)
     VERIFY_NOT_REACHED();
 }
 
-// 12.2.41 ISOMonthCode ( temporalObject ), https://tc39.es/proposal-temporal/#sec-temporal-isomonthcode
+// 12.2.40 ISOMonthCode ( temporalObject ), https://tc39.es/proposal-temporal/#sec-temporal-isomonthcode
 String iso_month_code(Object& temporal_object)
 {
     // 1. Assert: temporalObject has an [[ISOMonth]] internal slot.
@@ -953,7 +928,7 @@ String iso_month_code(Object& temporal_object)
     VERIFY_NOT_REACHED();
 }
 
-// 12.2.42 ISODay ( temporalObject ), https://tc39.es/proposal-temporal/#sec-temporal-isomonthcode
+// 12.2.41 ISODay ( temporalObject ), https://tc39.es/proposal-temporal/#sec-temporal-isomonthcode
 u8 iso_day(Object& temporal_object)
 {
     // 1. Assert: temporalObject has an [[ISODay]] internal slot.
@@ -971,7 +946,7 @@ u8 iso_day(Object& temporal_object)
     VERIFY_NOT_REACHED();
 }
 
-// 12.2.43 DefaultMergeFields ( fields, additionalFields ), https://tc39.es/proposal-temporal/#sec-temporal-defaultmergefields
+// 12.2.42 DefaultMergeFields ( fields, additionalFields ), https://tc39.es/proposal-temporal/#sec-temporal-defaultmergefields
 ThrowCompletionOr<Object*> default_merge_fields(GlobalObject& global_object, Object const& fields, Object const& additional_fields)
 {
     auto& vm = global_object.vm();

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

@@ -62,7 +62,6 @@ ThrowCompletionOr<PlainMonthDay*> calendar_month_day_from_fields(GlobalObject&,
 String format_calendar_annotation(StringView id, StringView show_calendar);
 ThrowCompletionOr<bool> calendar_equals(GlobalObject&, Object& one, Object& two);
 ThrowCompletionOr<Object*> consolidate_calendars(GlobalObject&, Object& one, Object& two);
-bool is_iso_leap_year(i32 year);
 u8 iso_days_in_month(i32 year, u8 month);
 u8 to_iso_day_of_week(i32 year, u8 month, u8 day);
 u16 to_iso_day_of_year(i32 year, u8 month, u8 day);

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

@@ -466,8 +466,12 @@ JS_DEFINE_NATIVE_FUNCTION(CalendarPrototype::in_leap_year)
         temporal_date_like = TRY(to_temporal_date(global_object, temporal_date_like));
     }
 
-    // 5. Return ! IsISOLeapYear(temporalDateLike.[[ISOYear]]).
-    return Value(is_iso_leap_year(iso_year(temporal_date_like.as_object())));
+    // 5. If InLeapYear(TimeFromYear(𝔽(temporalDateLike.[[ISOYear]]))) is 1𝔽, return true.
+    if (JS::in_leap_year(time_from_year(iso_year(temporal_date_like.as_object()))))
+        return Value(true);
+
+    // 6. Return false.
+    return Value(false);
 }
 
 // 12.4.21 Temporal.Calendar.prototype.fields ( fields ), https://tc39.es/proposal-temporal/#sec-temporal.calendar.prototype.fields