Implement Temporal.PlainDate[Time].{equals, add, subtract}

https://bugs.webkit.org/show_bug.cgi?id=245021

Reviewed by Yusuke Suzuki.

This patch implements three more methods -- equals, add, and subtract -- for the PlainDate and PlainDateTime classes.

This is all fairly straightforward aside from `balanceISODate`: When adding / subtracting a significant number of days,
we need to recalculate year and month based on total days away from Unix epoch.
(We could, of course, add years in a loop, but that would penalize large additions / subtractions.)

This function is based on existing logic in DateMath with two key differences.
  1. We don't need to worry about units smaller than days (vs. msToYear).
  2. We can calculate month and day together in a single loop (vs. dayInMonthFromDayInYear and monthFromDayInYear,
     which are wastefully separated for some reason. This should probably be fixed for Date in a separate patch.)

* JSTests/stress/temporal-calendar.js: Add tests.
* JSTests/stress/temporal-plaindate.js: Add tests.
* JSTests/stress/temporal-plaindatetime.js: Add tests.
* JSTests/test262/config.yaml: Update known failures (due to calendar support).
* Source/JavaScriptCore/runtime/ISO8601.cpp:
(JSC::ISO8601::weekOfYear): Use existing WTF helper.
(JSC::ISO8601::isYearWithinLimits): Added.
* Source/JavaScriptCore/runtime/ISO8601.h:
* Source/JavaScriptCore/runtime/TemporalCalendar.cpp:
(JSC::balanceISODate): Added.
(JSC::TemporalCalendar::isoDateAdd): Added.
(JSC::TemporalCalendar::equals): Added.
* Source/JavaScriptCore/runtime/TemporalCalendar.h:
* Source/JavaScriptCore/runtime/TemporalCalendarPrototype.cpp:
* Source/JavaScriptCore/runtime/TemporalObject.cpp:
(JSC::nonNegativeModulo): Moved from TemporalPlainTime.
* Source/JavaScriptCore/runtime/TemporalObject.h:
* Source/JavaScriptCore/runtime/TemporalPlainDate.cpp:
(JSC::TemporalPlainDate::toPlainDate):
* Source/JavaScriptCore/runtime/TemporalPlainDatePrototype.cpp:
* Source/JavaScriptCore/runtime/TemporalPlainDateTimePrototype.cpp:
* Source/JavaScriptCore/runtime/TemporalPlainTime.cpp:
(JSC::TemporalPlainTime::addTime): Made public static.
(JSC::nonNegativeModulo): Moved to TemporalObject.
(JSC::TemporalPlainTime::add const): Refactored away.
(JSC::TemporalPlainTime::subtract const): Refactored away.
* Source/JavaScriptCore/runtime/TemporalPlainTime.h:
* Source/JavaScriptCore/runtime/TemporalPlainTimePrototype.cpp:
* Source/WTF/wtf/DateMath.h: Expose two functions that were missing from the list.

Canonical link: https://commits.webkit.org/254366@main

JSTests/stress/temporal-calendar.js

@@ -97,6 +97,10 @@ shouldThrow(() => {
     shouldBe(JSON.parse(string, reviver).userCalendar instanceof Temporal.Calendar, true);
 }
 
+shouldBe(isoCalendar.toString(), isoCalendar.toJSON());
+shouldThrow(() => { Temporal.Calendar.prototype.toString.call({}); }, TypeError);
+shouldThrow(() => { Temporal.Calendar.prototype.toJSON.call({}); }, TypeError);
+
 shouldBe(Temporal.Calendar.prototype.dateFromFields.length, 1);
 shouldBe(isoCalendar.dateFromFields({ year: 2007, month: 1, day: 9 }).toString(), '2007-01-09');
 shouldBe(isoCalendar.dateFromFields({ year: 2007, monthCode: 'M01', day: 9 }).toString(), '2007-01-09');
@@ -113,3 +117,23 @@ shouldThrow(() => { isoCalendar.dateFromFields({ year: 2007, monthCode: 'M00', d
 shouldThrow(() => { isoCalendar.dateFromFields({ year: 2007, month: 1, day: 0 }); }, RangeError);
 shouldThrow(() => { isoCalendar.dateFromFields({ year: 2007, month: 1, monthCode: 'M02', day: 9 }); }, RangeError);
 shouldThrow(() => { isoCalendar.dateFromFields({ year: 2007, month: 20, day: 40 }, { overflow: 'reject' }); }, RangeError);
+
+shouldBe(Temporal.Calendar.prototype.dateAdd.length, 2);
+shouldBe(isoCalendar.dateAdd('2020-02-28', new Temporal.Duration()).toString(), '2020-02-28');
+shouldBe(isoCalendar.dateAdd('2020-02-28', { years: 1, months: 1 }).toString(), '2021-03-28');
+shouldBe(isoCalendar.dateAdd('2020-02-28', 'P1W1D').toString(), '2020-03-07');
+shouldBe(isoCalendar.dateAdd('2020-02-28', { hours: 24 }).toString(), '2020-02-29');
+shouldBe(isoCalendar.dateAdd('2020-02-28', { days: 36500000 }).toString(), '+101953-10-07');
+shouldBe(isoCalendar.dateAdd('2020-02-28', new Temporal.Duration(-1, -1, 0, -1)).toString(), '2019-01-27');
+shouldBe(isoCalendar.dateAdd('2020-01-30', { months: 1 }).toString(), '2020-02-29');
+shouldThrow(() => { isoCalendar.dateAdd('2020-01-30', { months: 1 }, { overflow: 'reject' }); }, RangeError);
+shouldThrow(() => { isoCalendar.dateAdd('2020-02-28', { years: 300000 }); }, RangeError);
+
+shouldBe(isoCalendar.dateAdd('2020-02-28', { years: -1, months: -1 }).toString(), '2019-01-28');
+shouldBe(isoCalendar.dateAdd('2020-02-28', '-P1W1D').toString(), '2020-02-20');
+shouldBe(isoCalendar.dateAdd('2020-02-28', { hours: -24 }).toString(), '2020-02-27');
+shouldBe(isoCalendar.dateAdd('2020-02-28', { days: -36500000 }).toString(), '-097914-07-21');
+shouldBe(isoCalendar.dateAdd('2020-02-28', new Temporal.Duration(1, 1, 0, 1)).toString(), '2021-03-29');
+shouldBe(isoCalendar.dateAdd('2020-03-30', { months: -1 }).toString(), '2020-02-29');
+shouldThrow(() => { isoCalendar.dateAdd('2020-03-30', { months: -1 }, { overflow: 'reject' }); }, RangeError);
+shouldThrow(() => { isoCalendar.dateAdd('2020-02-28', { years: -300000 }); }, RangeError);

JSTests/stress/temporal-plaindate.js

@@ -344,3 +344,36 @@ shouldThrow(() => { Temporal.PlainDate.from('2007-01-09').valueOf(); }, TypeErro
     let time = Temporal.PlainDate.from('2007-01-09');
     shouldBe(JSON.stringify(time.getISOFields()), `{"calendar":"iso8601","isoDay":9,"isoMonth":1,"isoYear":2007}`);
 }
+
+{
+    const ones = new Temporal.PlainDate(1,1,1);
+    shouldBe(ones.equals(new Temporal.PlainDate(1,1,1)), true);
+    shouldBe(ones.equals(new Temporal.PlainDate(2,1,1)), false);
+    shouldBe(ones.equals(new Temporal.PlainDate(1,2,1)), false);
+    shouldBe(ones.equals(new Temporal.PlainDate(1,1,2)), false);
+}
+
+shouldBe(Temporal.PlainDateTime.prototype.add.length, 1);
+shouldBe(Temporal.PlainDateTime.prototype.subtract.length, 1);
+{
+    const date = Temporal.PlainDate.from('2020-02-28');
+    shouldBe(date.add(new Temporal.Duration()).toString(), '2020-02-28');
+    shouldBe(date.add({ years: 1, months: 1 }).toString(), '2021-03-28');
+    shouldBe(date.add('P1W1D').toString(), '2020-03-07');
+    shouldBe(date.add({ hours: 24 }).toString(), '2020-02-29');
+    shouldBe(date.add({ days: 36500000 }).toString(), '+101953-10-07');
+    shouldBe(date.add(new Temporal.Duration(-1, -1, 0, -1)).toString(), '2019-01-27');
+    shouldBe(Temporal.PlainDate.from('2020-01-30').add({ months: 1 }).toString(), '2020-02-29');
+    shouldThrow(() => { Temporal.PlainDate.from('2020-01-30').add({ months: 1 }, { overflow: 'reject' }); }, RangeError);
+    shouldThrow(() => { date.add({ years: 300000 }); }, RangeError);
+
+    shouldBe(date.subtract(new Temporal.Duration()).toString(), '2020-02-28');
+    shouldBe(date.subtract({ years: 1, months: 1 }).toString(), '2019-01-28');
+    shouldBe(date.subtract('P1W1D').toString(), '2020-02-20');
+    shouldBe(date.subtract({ hours: 24 }).toString(), '2020-02-27');
+    shouldBe(date.subtract({ days: 36500000 }).toString(), '-097914-07-21');
+    shouldBe(date.subtract(new Temporal.Duration(-1, -1, 0, -1)).toString(), '2021-03-29');
+    shouldBe(Temporal.PlainDate.from('2020-03-30').subtract({ months: 1 }).toString(), '2020-02-29');
+    shouldThrow(() => { Temporal.PlainDate.from('2020-03-30').subtract({ months: 1 }, { overflow: 'reject' }); }, RangeError);
+    shouldThrow(() => { date.subtract({ years: 300000 }); }, RangeError);
+}

JSTests/stress/temporal-plaindatetime.js

@@ -239,3 +239,34 @@ shouldBe(pdt.toPlainTime().toString(), '04:05:06.007008009');
 
 shouldBe(Temporal.PlainDateTime.prototype.valueOf.length, 0);
 shouldThrow(() => pdt.valueOf(), TypeError);
+
+shouldBe(pdt.equals(new Temporal.PlainDateTime(1,2,3,4,5,6,7,8,9)), true);
+shouldBe(pdt.equals(new Temporal.PlainDateTime(2,2,3,4,5,6,7,8,9)), false);
+shouldBe(pdt.equals(new Temporal.PlainDateTime(1,3,3,4,5,6,7,8,9)), false);
+shouldBe(pdt.equals(new Temporal.PlainDateTime(1,2,4,4,5,6,7,8,9)), false);
+shouldBe(pdt.equals(new Temporal.PlainDateTime(1,2,3,5,5,6,7,8,9)), false);
+shouldBe(pdt.equals(new Temporal.PlainDateTime(1,2,3,4,6,6,7,8,9)), false);
+shouldBe(pdt.equals(new Temporal.PlainDateTime(1,2,3,4,5,7,7,8,9)), false);
+shouldBe(pdt.equals(new Temporal.PlainDateTime(1,2,3,4,5,6,8,8,9)), false);
+shouldBe(pdt.equals(new Temporal.PlainDateTime(1,2,3,4,5,6,7,9,9)), false);
+shouldBe(pdt.equals(new Temporal.PlainDateTime(1,2,3,4,5,6,7,8,1)), false);
+
+shouldBe(Temporal.PlainDateTime.prototype.add.length, 1);
+shouldBe(pdt.add(new Temporal.Duration()).toString(), '0001-02-03T04:05:06.007008009');
+shouldBe(pdt.add(new Temporal.Duration(1,1,1,1,1,1,1,1,1,1)).toString(), '0002-03-11T05:06:07.00800901');
+shouldBe(pdt.add('-P1Y1M1DT1H1M1.001001001S').toString(), '0000-01-02T03:04:05.006007008');
+shouldBe(pdt.add({ hours: 24 }).toString(), '0001-02-04T04:05:06.007008009');
+shouldBe(pdt.add(new Temporal.Duration(0,10,3,7,19,54,53,992,991,991)).toString(), '0002-01-01T00:00:00');
+shouldBe(Temporal.PlainDateTime.from('2020-01-30').add({ months: 1 }).toString(), '2020-02-29T00:00:00');
+shouldThrow(() => { Temporal.PlainDateTime.from('2020-01-30').add({ months: 1 }, { overflow: 'reject' }); }, RangeError);
+shouldThrow(() => { pdt.add({ years: 300000 }); }, RangeError);
+
+shouldBe(Temporal.PlainDateTime.prototype.subtract.length, 1);
+shouldBe(pdt.subtract(new Temporal.Duration()).toString(), '0001-02-03T04:05:06.007008009');
+shouldBe(pdt.subtract(new Temporal.Duration(1,1,0,1,1,1,1,1,1,1)).toString(), '0000-01-02T03:04:05.006007008');
+shouldBe(pdt.subtract('-P1Y1M1W1DT1H1M1.001001001S').toString(), '0002-03-11T05:06:07.00800901');
+shouldBe(pdt.subtract({ hours: 24 }).toString(), '0001-02-02T04:05:06.007008009');
+shouldBe(pdt.subtract(new Temporal.Duration(0,1,5,3,4,5,6,7,8,10)).toString(), '0000-11-25T23:59:59.999999999');
+shouldBe(Temporal.PlainDateTime.from('2020-03-30').subtract({ months: 1 }).toString(), '2020-02-29T00:00:00');
+shouldThrow(() => { Temporal.PlainDateTime.from('2020-03-30').subtract({ months: 1 }, { overflow: 'reject' }); }, RangeError);
+shouldThrow(() => { pdt.subtract({ years: 300000 }); }, RangeError);

JSTests/test262/config.yaml

@@ -36,21 +36,15 @@ skip:
     - test/built-ins/Temporal/Now/plainTimeISO
     - test/built-ins/Temporal/Now/zonedDateTime
     - test/built-ins/Temporal/Now/zonedDateTimeISO
-    - test/built-ins/Temporal/PlainDate/prototype/add
-    - test/built-ins/Temporal/PlainDate/prototype/equals
     - test/built-ins/Temporal/PlainDate/prototype/since
-    - test/built-ins/Temporal/PlainDate/prototype/subtract
     - test/built-ins/Temporal/PlainDate/prototype/toPlainMonthDay
     - test/built-ins/Temporal/PlainDate/prototype/toPlainYearMonth
     - test/built-ins/Temporal/PlainDate/prototype/toZonedDateTime
     - test/built-ins/Temporal/PlainDate/prototype/until
     - test/built-ins/Temporal/PlainDate/prototype/with
     - test/built-ins/Temporal/PlainDate/prototype/withCalendar
-    - test/built-ins/Temporal/PlainDateTime/prototype/add
-    - test/built-ins/Temporal/PlainDateTime/prototype/equals
     - test/built-ins/Temporal/PlainDateTime/prototype/round
     - test/built-ins/Temporal/PlainDateTime/prototype/since
-    - test/built-ins/Temporal/PlainDateTime/prototype/subtract
     - test/built-ins/Temporal/PlainDateTime/prototype/toPlainMonthDay
     - test/built-ins/Temporal/PlainDateTime/prototype/toPlainYearMonth
     - test/built-ins/Temporal/PlainDateTime/prototype/toZonedDateTime
@@ -368,6 +362,7 @@ skip:
     # Depends on Calendar support
     - test/built-ins/Temporal/PlainDate/basic.js
     - test/built-ins/Temporal/PlainDate/calendar-number.js
+    - test/built-ins/Temporal/PlainDate/calendar-temporal-object.js
     - test/built-ins/Temporal/PlainDate/calendar-wrong-type.js
     - test/built-ins/Temporal/PlainDate/compare/argument-calendar-datefromfields-called-with-null-prototype-fields.js
     - test/built-ins/Temporal/PlainDate/compare/argument-propertybag-calendar-leap-second.js
@@ -388,16 +383,34 @@ skip:
     - test/built-ins/Temporal/PlainDate/from/calendar-fields-custom.js
     - test/built-ins/Temporal/PlainDate/from/calendar-fields-iterable.js
     - test/built-ins/Temporal/PlainDate/from/calendar-temporal-object.js
+    - test/built-ins/Temporal/PlainDate/prototype/add/balance-smaller-units.js
+    - test/built-ins/Temporal/PlainDate/prototype/add/calendar-invalid-return.js
+    - test/built-ins/Temporal/PlainDate/prototype/add/custom.js
     - test/built-ins/Temporal/PlainDate/prototype/day/calendar-returns-infinity.js
     - test/built-ins/Temporal/PlainDate/prototype/dayOfWeek/custom.js
     - test/built-ins/Temporal/PlainDate/prototype/dayOfYear/custom.js
     - test/built-ins/Temporal/PlainDate/prototype/daysInMonth/custom.js
     - test/built-ins/Temporal/PlainDate/prototype/daysInWeek/custom.js
     - test/built-ins/Temporal/PlainDate/prototype/daysInYear/custom.js
+    - test/built-ins/Temporal/PlainDate/prototype/equals/argument-calendar-datefromfields-called-with-null-prototype-fields.js
+    - test/built-ins/Temporal/PlainDate/prototype/equals/argument-object-valid.js
+    - test/built-ins/Temporal/PlainDate/prototype/equals/argument-propertybag-calendar-leap-second.js
+    - test/built-ins/Temporal/PlainDate/prototype/equals/argument-propertybag-calendar-number.js
+    - test/built-ins/Temporal/PlainDate/prototype/equals/argument-propertybag-calendar-wrong-type.js
+    - test/built-ins/Temporal/PlainDate/prototype/equals/argument-string-invalid.js
+    - test/built-ins/Temporal/PlainDate/prototype/equals/argument-string.js
+    - test/built-ins/Temporal/PlainDate/prototype/equals/calendar-call-different.js
+    - test/built-ins/Temporal/PlainDate/prototype/equals/calendar-call-same.js
+    - test/built-ins/Temporal/PlainDate/prototype/equals/calendar-datefromfields-called-with-options-undefined.js
+    - test/built-ins/Temporal/PlainDate/prototype/equals/calendar-fields-iterable.js
+    - test/built-ins/Temporal/PlainDate/prototype/equals/calendar-temporal-object.js
     - test/built-ins/Temporal/PlainDate/prototype/getISOFields/custom.js
     - test/built-ins/Temporal/PlainDate/prototype/inLeapYear/custom.js
     - test/built-ins/Temporal/PlainDate/prototype/month/calendar-returns-infinity.js
     - test/built-ins/Temporal/PlainDate/prototype/monthsInYear/custom.js
+    - test/built-ins/Temporal/PlainDate/prototype/subtract/balance-smaller-units.js
+    - test/built-ins/Temporal/PlainDate/prototype/subtract/calendar-invalid-return.js
+    - test/built-ins/Temporal/PlainDate/prototype/subtract/custom.js
     - test/built-ins/Temporal/PlainDate/prototype/toPlainDateTime/argument-object.js
     - test/built-ins/Temporal/PlainDate/prototype/toPlainDateTime/basic.js
     - test/built-ins/Temporal/PlainDate/prototype/toPlainDateTime/calendar-temporal-object.js
@@ -414,13 +427,13 @@ skip:
     - test/built-ins/Temporal/PlainDateTime/calendar-number.js
     - test/built-ins/Temporal/PlainDateTime/calendar-temporal-object.js
     - test/built-ins/Temporal/PlainDateTime/calendar-wrong-type.js
-    - test/built-ins/Temporal/PlainDateTime/constructor-full.js
     - test/built-ins/Temporal/PlainDateTime/compare/argument-propertybag-calendar-leap-second.js
     - test/built-ins/Temporal/PlainDateTime/compare/argument-propertybag-calendar-number.js
     - test/built-ins/Temporal/PlainDateTime/compare/argument-propertybag-calendar-wrong-type.js
     - test/built-ins/Temporal/PlainDateTime/compare/calendar-datefromfields-called-with-null-prototype-fields.js
     - test/built-ins/Temporal/PlainDateTime/compare/calendar-fields-iterable.js
     - test/built-ins/Temporal/PlainDateTime/compare/calendar-temporal-object.js
+    - test/built-ins/Temporal/PlainDateTime/constructor-full.js
     - test/built-ins/Temporal/PlainDateTime/from/argument-plaindate.js
     - test/built-ins/Temporal/PlainDateTime/from/argument-propertybag-calendar-leap-second.js
     - test/built-ins/Temporal/PlainDateTime/from/argument-propertybag-calendar-number.js
@@ -431,16 +444,25 @@ skip:
     - test/built-ins/Temporal/PlainDateTime/from/calendar-temporal-object.js
     - test/built-ins/Temporal/PlainDateTime/from/overflow-invalid-string.js
     - test/built-ins/Temporal/PlainDateTime/from/overflow-wrong-type.js
+    - test/built-ins/Temporal/PlainDateTime/prototype/add/calendar-dateadd.js
     - test/built-ins/Temporal/PlainDateTime/prototype/day/calendar-returns-infinity.js
     - test/built-ins/Temporal/PlainDateTime/prototype/dayOfWeek/custom.js
     - test/built-ins/Temporal/PlainDateTime/prototype/dayOfYear/custom.js
     - test/built-ins/Temporal/PlainDateTime/prototype/daysInMonth/custom.js
     - test/built-ins/Temporal/PlainDateTime/prototype/daysInWeek/custom.js
     - test/built-ins/Temporal/PlainDateTime/prototype/daysInYear/custom.js
+    - test/built-ins/Temporal/PlainDateTime/prototype/equals/argument-propertybag-calendar-leap-second.js
+    - test/built-ins/Temporal/PlainDateTime/prototype/equals/argument-propertybag-calendar-number.js
+    - test/built-ins/Temporal/PlainDateTime/prototype/equals/argument-propertybag-calendar-wrong-type.js
+    - test/built-ins/Temporal/PlainDateTime/prototype/equals/calendar-checked.js
+    - test/built-ins/Temporal/PlainDateTime/prototype/equals/calendar-datefromfields-called-with-null-prototype-fields.js
+    - test/built-ins/Temporal/PlainDateTime/prototype/equals/calendar-fields-iterable.js
+    - test/built-ins/Temporal/PlainDateTime/prototype/equals/calendar-temporal-object.js
     - test/built-ins/Temporal/PlainDateTime/prototype/getISOFields/custom.js
     - test/built-ins/Temporal/PlainDateTime/prototype/inLeapYear/custom.js
     - test/built-ins/Temporal/PlainDateTime/prototype/month/calendar-returns-infinity.js
     - test/built-ins/Temporal/PlainDateTime/prototype/monthsInYear/custom.js
+    - test/built-ins/Temporal/PlainDateTime/prototype/subtract/calendar-dateadd.js
     - test/built-ins/Temporal/PlainDateTime/prototype/toString/calendarname-always.js
     - test/built-ins/Temporal/PlainDateTime/prototype/toString/calendarname-auto.js
     - test/built-ins/Temporal/PlainDateTime/prototype/toString/calendarname-invalid-string.js
@@ -472,7 +494,6 @@ skip:
     - test/built-ins/Temporal/Duration/prototype/total/unit-plurals-accepted-string.js
     - test/built-ins/Temporal/Duration/prototype/total/unit-plurals-accepted.js
     - test/built-ins/Temporal/Instant/prototype/toString/smallestunit-plurals-accepted.js
-    - test/built-ins/Temporal/PlainDate/calendar-temporal-object.js
     - test/built-ins/Temporal/PlainDateTime/prototype/toString/smallestunit-plurals-accepted.js
     - test/built-ins/Temporal/PlainTime/prototype/round/smallestunit-plurals-accepted.js
     - test/built-ins/Temporal/PlainTime/prototype/toString/smallestunit-plurals-accepted.js
@@ -551,6 +572,12 @@ skip:
     - test/built-ins/Temporal/PlainDate/from/argument-zoneddatetime-timezone-getoffsetnanosecondsfor-wrong-type.js
     - test/built-ins/Temporal/PlainDate/from/argument-zoneddatetime.js
     - test/built-ins/Temporal/PlainDate/from/overflow-invalid-string.js
+    - test/built-ins/Temporal/PlainDate/prototype/equals/argument-zoneddatetime-convert.js
+    - test/built-ins/Temporal/PlainDate/prototype/equals/argument-zoneddatetime-slots.js
+    - test/built-ins/Temporal/PlainDate/prototype/equals/argument-zoneddatetime-timezone-getoffsetnanosecondsfor-non-integer.js
+    - test/built-ins/Temporal/PlainDate/prototype/equals/argument-zoneddatetime-timezone-getoffsetnanosecondsfor-not-callable.js
+    - test/built-ins/Temporal/PlainDate/prototype/equals/argument-zoneddatetime-timezone-getoffsetnanosecondsfor-out-of-range.js
+    - test/built-ins/Temporal/PlainDate/prototype/equals/argument-zoneddatetime-timezone-getoffsetnanosecondsfor-wrong-type.js
     - test/built-ins/Temporal/PlainDate/prototype/toPlainDateTime/argument-zoneddatetime-balance-negative-time-units.js
     - test/built-ins/Temporal/PlainDate/prototype/toPlainDateTime/argument-zoneddatetime-negative-epochnanoseconds.js
     - test/built-ins/Temporal/PlainDate/prototype/toPlainDateTime/argument-zoneddatetime-timezone-getoffsetnanosecondsfor-non-integer.js
@@ -568,6 +595,12 @@ skip:
     - test/built-ins/Temporal/PlainDateTime/from/argument-zoneddatetime-timezone-getoffsetnanosecondsfor-not-callable.js
     - test/built-ins/Temporal/PlainDateTime/from/argument-zoneddatetime-timezone-getoffsetnanosecondsfor-out-of-range.js
     - test/built-ins/Temporal/PlainDateTime/from/argument-zoneddatetime-timezone-getoffsetnanosecondsfor-wrong-type.js
+    - test/built-ins/Temporal/PlainDateTime/prototype/equals/argument-zoneddatetime-balance-negative-time-units.js
+    - test/built-ins/Temporal/PlainDateTime/prototype/equals/argument-zoneddatetime-negative-epochnanoseconds.js
+    - test/built-ins/Temporal/PlainDateTime/prototype/equals/argument-zoneddatetime-timezone-getoffsetnanosecondsfor-non-integer.js
+    - test/built-ins/Temporal/PlainDateTime/prototype/equals/argument-zoneddatetime-timezone-getoffsetnanosecondsfor-not-callable.js
+    - test/built-ins/Temporal/PlainDateTime/prototype/equals/argument-zoneddatetime-timezone-getoffsetnanosecondsfor-out-of-range.js
+    - test/built-ins/Temporal/PlainDateTime/prototype/equals/argument-zoneddatetime-timezone-getoffsetnanosecondsfor-wrong-type.js
     - test/built-ins/Temporal/PlainTime/compare/argument-zoneddatetime-negative-epochnanoseconds.js
     - test/built-ins/Temporal/PlainTime/compare/argument-zoneddatetime-timezone-getoffsetnanosecondsfor-non-integer.js
     - test/built-ins/Temporal/PlainTime/compare/argument-zoneddatetime-timezone-getoffsetnanosecondsfor-not-callable.js

Source/JavaScriptCore/runtime/ISO8601.cpp

@@ -45,6 +45,9 @@ static constexpr int64_t nsPerSecond = 1000LL * 1000 * 1000;
 static constexpr int64_t nsPerMillisecond = 1000LL * 1000;
 static constexpr int64_t nsPerMicrosecond = 1000LL;
 
+static constexpr int32_t maxYear = 275760;
+static constexpr int32_t minYear = -271821;
+
 std::optional<TimeZoneID> parseTimeZoneName(StringView string)
 {
     const auto& timeZones = intlAvailableTimeZones();
@@ -1166,8 +1169,7 @@ uint8_t weekOfYear(PlainDate plainDate)
 
     if (week == 53) {
         // Check whether this is in next year's week 1.
-        int32_t daysInYear = isLeapYear(plainDate.year()) ? 366 : 365;
-        if ((daysInYear - dayOfYear) < (4 - dayOfWeek))
+        if ((daysInYear(plainDate.year()) - dayOfYear) < (4 - dayOfWeek))
             return 1;
     }
 
@@ -1460,5 +1462,11 @@ bool isDateTimeWithinLimits(int32_t year, uint8_t month, uint8_t day, unsigned h
     return true;
 }
 
+// More effective for our purposes than isInBounds<int32_t>.
+bool isYearWithinLimits(double year)
+{
+    return year >= minYear && year <= maxYear;
+}
+
 } // namespace ISO8601
 } // namespace JSC