The Temporal proposal reached Stage 3 on 2021-03-10, and like all ECMA262 proposals, it needs coverage in Test262 to advance to Stage 4. In terms of normative text, it is easily the largest proposal we've seen. Testing it will definitely require significant time, effort, and coordination (even with the proposal's existing tests as a starting point). We'd like to document progress publicly for transparency and to encourage participation.

To get the ball rolling, I'm suggesting that we track progress on an per-API basis using this GitHub.com issue. Compared to alternatives like collaborative document editing services and an in-repository text file, this seems like it balances ease of hosting, maintainability, and proximity to the tests. This approach worked well for ES6's well-known Symbols--the most similar (though much smaller) effort that comes to mind.

Working mode

Anyone can comment here when they'd like to begin writing tests for a specific API. A maintainer will update the list to reflect the ongoing and completed work. When you submit a pull request, please mention this issue (just write "gh-3002") so GitHub displays the status of your work in this thread.

Tests for multiple APIs can be submitted in a single pull request, but patches should be small enough for another contributor to review them in a single session. For instance, it probably makes sense to submit tests for all of the @@toStringTag methods in one patch. There's some subjectivity here, but when in doubt, we should err on the side of smaller patches (and remain open to reviewers' requests to break up pull requests).

Status

• Temporal.now.timeZone (reviewed @Ms2ger 2022-04-13)
• Temporal.now.instant (reviewed @Ms2ger 2022-04-13)
• Temporal.Now.plainDateTime
• Temporal.Now.plainDateTimeISO
• Temporal.Now.zonedDateTime
• Temporal.Now.zonedDateTimeISO
• Temporal.Now.plainDate
• Temporal.Now.plainDateISO
• Temporal.Now.plainTimeISO
• Temporal.PlainDate (reviewed @Ms2ger 2022-06-20)
• Temporal.PlainDate.from (reviewed @Ms2ger 2022-06-20)
• Temporal.PlainDate.compare (reviewed @Ms2ger 2022-06-20)
• Temporal.PlainDate.prototype.constructor (reviewed @Ms2ger 2022-06-20)
• Temporal.PlainDate.prototype[ @@toStringTag ] (reviewed @Ms2ger 2022-05-19)
• Temporal.PlainDate.prototype.calendar (reviewed @Ms2ger 2022-05-25)
• Temporal.PlainDate.prototype.year (reviewed @Ms2ger 2022-05-25)
• Temporal.PlainDate.prototype.month (reviewed @Ms2ger 2022-05-25)
• Temporal.PlainDate.prototype.monthCode (reviewed @Ms2ger 2022-05-25)
• Temporal.PlainDate.prototype.day (reviewed @Ms2ger 2022-05-25)
• Temporal.PlainDate.prototype.dayOfWeek (reviewed @Ms2ger 2022-06-20)
• Temporal.PlainDate.prototype.dayOfYear (reviewed @Ms2ger 2022-06-20)
• Temporal.PlainDate.prototype.weekOfYear (reviewed @Ms2ger 2022-06-20)
• Temporal.PlainDate.prototype.daysInWeek (reviewed @Ms2ger 2022-06-20)
• Temporal.PlainDate.prototype.daysInMonth (reviewed @Ms2ger 2022-06-20)
• Temporal.PlainDate.prototype.daysInYear (reviewed @Ms2ger 2022-06-20)
• Temporal.PlainDate.prototype.monthsInYear (reviewed @Ms2ger 2022-06-20)
• Temporal.PlainDate.prototype.inLeapYear (reviewed @Ms2ger 2022-06-20)
• Temporal.PlainDate.prototype.toPlainYearMonth (reviewed @Ms2ger 2022-06-20)
• Temporal.PlainDate.prototype.toPlainMonthDay (reviewed @Ms2ger 2022-06-20)
• Temporal.PlainDate.prototype.getISOFields (reviewed @Ms2ger 2022-06-20)
• Temporal.PlainDate.prototype.add (reviewed @Ms2ger 2022-06-20)
• Temporal.PlainDate.prototype.subtract (reviewed @Ms2ger 2022-06-20)
• Temporal.PlainDate.prototype.with (reviewed @Ms2ger 2022-06-20)
• Temporal.PlainDate.prototype.withCalendar (reviewed @Ms2ger 2022-06-20)
• Temporal.PlainDate.prototype.until (reviewed @Ms2ger 2022-06-20)
• Temporal.PlainDate.prototype.since (reviewed @Ms2ger 2022-06-20)
• Temporal.PlainDate.prototype.equals (reviewed @Ms2ger 2022-06-20)
• Temporal.PlainDate.prototype.toPlainDateTime (reviewed @Ms2ger 2022-06-20)
• Temporal.PlainDate.prototype.toZonedDateTime (reviewed @Ms2ger 2022-06-20)
• Temporal.PlainDate.prototype.toString (reviewed @Ms2ger 2022-06-20)
• Temporal.PlainDate.prototype.toLocaleString
• Temporal.PlainDate.prototype.toJSON (reviewed @Ms2ger 2022-06-20)
• Temporal.PlainDate.prototype.valueOf (reviewed @Ms2ger 2022-05-25)
• Temporal.PlainTime
• Temporal.PlainTime.from
• Temporal.PlainTime.compare
• Temporal.PlainTime.prototype.constructor (reviewed @ptomato 2022-08-03)
• Temporal.PlainTime.prototype[ @@toStringTag ] (reviewed @Ms2ger 2022-05-19)
• Temporal.PlainTime.prototype.calendar (reviewed @Ms2ger 2022-05-19)
• Temporal.PlainTime.prototype.hour (reviewed @Ms2ger 2022-05-19)
• Temporal.PlainTime.prototype.minute (reviewed @Ms2ger 2022-05-19)
• Temporal.PlainTime.prototype.second (reviewed @Ms2ger 2022-05-19)
• Temporal.PlainTime.prototype.millisecond (reviewed @Ms2ger 2022-05-19)
• Temporal.PlainTime.prototype.microsecond (reviewed @Ms2ger 2022-05-19)
• Temporal.PlainTime.prototype.nanosecond (reviewed @Ms2ger 2022-05-19)
• Temporal.PlainTime.prototype.add
• Temporal.PlainTime.prototype.subtract
• Temporal.PlainTime.prototype.with
• Temporal.PlainTime.prototype.until
• Temporal.PlainTime.prototype.since
• Temporal.PlainTime.prototype.round
• Temporal.PlainTime.prototype.equals
• Temporal.PlainTime.prototype.toPlainDateTime
• Temporal.PlainTime.prototype.toZonedDateTime
• Temporal.PlainTime.prototype.getISOFields (reviewed @ptomato 2022-08-03)
• Temporal.PlainTime.prototype.toString
• Temporal.PlainTime.prototype.toLocaleString
• Temporal.PlainTime.prototype.toJSON (reviewed @Ms2ger 2022-05-19)
• Temporal.PlainTime.prototype.valueOf (reviewed @Ms2ger 2022-05-19)
• Temporal.PlainDateTime
• Temporal.PlainDateTime.from
• Temporal.PlainDateTime.compare
• Temporal.PlainDateTime.prototype.constructor (reviewed @ptomato 2022-08-03)
• Temporal.PlainDateTime.prototype[ @@toStringTag ] (reviewed @Ms2ger 2022-05-19)
• Temporal.PlainDateTime.prototype.calendar
• Temporal.PlainDateTime.prototype.year
• Temporal.PlainDateTime.prototype.month
• Temporal.PlainDateTime.prototype.monthCode
• Temporal.PlainDateTime.prototype.day
• Temporal.PlainDateTime.prototype.hour
• Temporal.PlainDateTime.prototype.minute
• Temporal.PlainDateTime.prototype.second
• Temporal.PlainDateTime.prototype.millisecond
• Temporal.PlainDateTime.prototype.microsecond
• Temporal.PlainDateTime.prototype.nanosecond
• Temporal.PlainDateTime.prototype.dayOfWeek
• Temporal.PlainDateTime.prototype.dayOfYear
• Temporal.PlainDateTime.prototype.weekOfYear
• Temporal.PlainDateTime.prototype.daysInWeek
• Temporal.PlainDateTime.prototype.daysInMonth
• Temporal.PlainDateTime.prototype.daysInYear
• Temporal.PlainDateTime.prototype.monthsInYear
• Temporal.PlainDateTime.prototype.inLeapYear
• Temporal.PlainDateTime.prototype.with
• Temporal.PlainDateTime.prototype.withPlainTime
• Temporal.PlainDateTime.prototype.withPlainDate
• Temporal.PlainDateTime.prototype.withCalendar
• Temporal.PlainDateTime.prototype.add
• Temporal.PlainDateTime.prototype.subtract
• Temporal.PlainDateTime.prototype.until
• Temporal.PlainDateTime.prototype.since
• Temporal.PlainDateTime.prototype.round
• Temporal.PlainDateTime.prototype.equals
• Temporal.PlainDateTime.prototype.toString
• Temporal.PlainDateTime.prototype.toLocaleString
• Temporal.PlainDateTime.prototype.toJSON
• Temporal.PlainDateTime.prototype.valueOf
• Temporal.PlainDateTime.prototype.toZonedDateTime
• Temporal.PlainDateTime.prototype.toPlainDate
• Temporal.PlainDateTime.prototype.toPlainYearMonth
• Temporal.PlainDateTime.prototype.toPlainMonthDay
• Temporal.PlainDateTime.prototype.toPlainTime
• Temporal.PlainDateTime.prototype.getISOFields (reviewed @ptomato 2022-08-03)
• Temporal.ZonedDateTime
• Temporal.ZonedDateTime.from
• Temporal.ZonedDateTime.compare
• Temporal.ZonedDateTime.prototype.constructor (reviewed @ptomato 2022-08-03)
• Temporal.ZonedDateTime.prototype[ @@toStringTag ] (reviewed @Ms2ger 2022-05-19)
• Temporal.ZonedDateTime.prototype.calendar
• Temporal.ZonedDateTime.prototype.timeZone
• Temporal.ZonedDateTime.prototype.year
• Temporal.ZonedDateTime.prototype.month
• Temporal.ZonedDateTime.prototype.monthCode
• Temporal.ZonedDateTime.prototype.day
• Temporal.ZonedDateTime.prototype.hour
• Temporal.ZonedDateTime.prototype.minute
• Temporal.ZonedDateTime.prototype.second
• Temporal.ZonedDateTime.prototype.millisecond
• Temporal.ZonedDateTime.prototype.microsecond
• Temporal.ZonedDateTime.prototype.nanosecond
• Temporal.ZonedDateTime.prototype.epochSeconds
• Temporal.ZonedDateTime.prototype.epochMilliseconds
• Temporal.ZonedDateTime.prototype.epochMicroseconds
• Temporal.ZonedDateTime.prototype.epochNanoseconds
• Temporal.ZonedDateTime.prototype.dayOfWeek
• Temporal.ZonedDateTime.prototype.dayOfYear
• Temporal.ZonedDateTime.prototype.weekOfYear
• Temporal.ZonedDateTime.prototype.hoursInDay
• Temporal.ZonedDateTime.prototype.daysInWeek
• Temporal.ZonedDateTime.prototype.daysInMonth
• Temporal.ZonedDateTime.prototype.daysInYear
• Temporal.ZonedDateTime.prototype.monthsInYear
• Temporal.ZonedDateTime.prototype.inLeapYear
• Temporal.ZonedDateTime.prototype.offsetNanoseconds
• Temporal.ZonedDateTime.prototype.offset
• Temporal.ZonedDateTime.prototype.with
• Temporal.ZonedDateTime.prototype.withPlainTime
• Temporal.ZonedDateTime.prototype.withPlainDate
• Temporal.ZonedDateTime.prototype.withTimeZone
• Temporal.ZonedDateTime.prototype.withCalendar
• Temporal.ZonedDateTime.prototype.add
• Temporal.ZonedDateTime.prototype.subtract
• Temporal.ZonedDateTime.prototype.until
• Temporal.ZonedDateTime.prototype.since
• Temporal.ZonedDateTime.prototype.round
• Temporal.ZonedDateTime.prototype.equals
• Temporal.ZonedDateTime.prototype.toString
• Temporal.ZonedDateTime.prototype.toLocaleString
• Temporal.ZonedDateTime.prototype.toJSON
• Temporal.ZonedDateTime.prototype.valueOf
• Temporal.ZonedDateTime.prototype.startOfDay
• Temporal.ZonedDateTime.prototype.toInstant
• Temporal.ZonedDateTime.prototype.toPlainDate
• Temporal.ZonedDateTime.prototype.toPlainTime
• Temporal.ZonedDateTime.prototype.toPlainDateTime
• Temporal.ZonedDateTime.prototype.toPlainYearMonth
• Temporal.ZonedDateTime.prototype.toPlainMonthDay
• Temporal.ZonedDateTime.prototype.getISOFields
• Temporal.Duration
• Temporal.Duration.from
• Temporal.Duration.compare
• Temporal.Duration.prototype.constructor (reviewed @ptomato 2022-08-03)
• Temporal.Duration.prototype[ @@toStringTag ] (reviewed @Ms2ger 2022-05-19)
• Temporal.Duration.prototype.years
• Temporal.Duration.prototype.months
• Temporal.Duration.prototype.weeks
• Temporal.Duration.prototype.days
• Temporal.Duration.prototype.hours
• Temporal.Duration.prototype.minutes
• Temporal.Duration.prototype.seconds
• Temporal.Duration.prototype.milliseconds
• Temporal.Duration.prototype.microseconds
• Temporal.Duration.prototype.nanoseconds
• Temporal.Duration.prototype.sign
• Temporal.Duration.prototype.blank
• Temporal.Duration.prototype.with
• Temporal.Duration.prototype.negated
• Temporal.Duration.prototype.abs
• Temporal.Duration.prototype.add
• Temporal.Duration.prototype.subtract
• Temporal.Duration.prototype.round
• Temporal.Duration.prototype.total
• Temporal.Duration.prototype.toString
• Temporal.Duration.prototype.toJSON
• Temporal.Duration.prototype.toLocaleString
• Temporal.Duration.prototype.valueOf
• Temporal.Instant
• Temporal.Instant.from
• Temporal.Instant.fromEpochSeconds
• Temporal.Instant.fromEpochMilliseconds
• Temporal.Instant.fromEpochMicroseconds
• Temporal.Instant.fromEpochNanoseconds
• Temporal.Instant.compare
• Temporal.Instant.prototype.constructor (reviewed @ptomato 2022-08-03)
• Temporal.Instant.prototype[ @@toStringTag ] (reviewed @Ms2ger 2022-05-19)
• Temporal.Instant.prototype.epochSeconds
• Temporal.Instant.prototype.epochMilliseconds
• Temporal.Instant.prototype.epochMicroseconds
• Temporal.Instant.prototype.epochNanoseconds
• Temporal.Instant.prototype.add
• Temporal.Instant.prototype.subtract
• Temporal.Instant.prototype.until
• Temporal.Instant.prototype.since
• Temporal.Instant.prototype.round
• Temporal.Instant.prototype.equals
• Temporal.Instant.prototype.toString
• Temporal.Instant.prototype.toLocaleString
• Temporal.Instant.prototype.toJSON
• Temporal.Instant.prototype.valueOf
• Temporal.Instant.prototype.toZonedDateTime
• Temporal.Instant.prototype.toZonedDateTimeISO
• Temporal.PlainYearMonth
• Temporal.PlainYearMonth.from
• Temporal.PlainYearMonth.compare
• Temporal.PlainYearMonth.prototype.constructor (reviewed @ptomato 2022-08-03)
• Temporal.PlainYearMonth.prototype[ @@toStringTag ] (reviewed @Ms2ger 2022-05-19)
• Temporal.PlainYearMonth.prototype.calendar
• Temporal.PlainYearMonth.prototype.year
• Temporal.PlainYearMonth.prototype.month
• Temporal.PlainYearMonth.prototype.monthCode
• Temporal.PlainYearMonth.prototype.daysInYear
• Temporal.PlainYearMonth.prototype.daysInMonth
• Temporal.PlainYearMonth.prototype.monthsInYear
• Temporal.PlainYearMonth.prototype.inLeapYear
• Temporal.PlainYearMonth.prototype.with
• Temporal.PlainYearMonth.prototype.add
• Temporal.PlainYearMonth.prototype.subtract
• Temporal.PlainYearMonth.prototype.until
• Temporal.PlainYearMonth.prototype.since
• Temporal.PlainYearMonth.prototype.equals
• Temporal.PlainYearMonth.prototype.toString
• Temporal.PlainYearMonth.prototype.toLocaleString
• Temporal.PlainYearMonth.prototype.toJSON
• Temporal.PlainYearMonth.prototype.valueOf
• Temporal.PlainYearMonth.prototype.toPlainDate
• Temporal.PlainYearMonth.prototype.getISOFields (reviewed @ptomato 2022-08-03)
• Temporal.PlainMonthDay
• Temporal.PlainMonthDay.from
• Temporal.PlainMonthDay.prototype.constructor (reviewed @ptomato 2022-08-03)
• Temporal.PlainMonthDay.prototype[ @@toStringTag ] (reviewed @Ms2ger 2022-05-19)
• Temporal.PlainMonthDay.prototype.calendar
• Temporal.PlainMonthDay.prototype.monthCode
• Temporal.PlainMonthDay.prototype.day
• Temporal.PlainMonthDay.prototype.with
• Temporal.PlainMonthDay.prototype.equals
• Temporal.PlainMonthDay.prototype.toString
• Temporal.PlainMonthDay.prototype.toLocaleString
• Temporal.PlainMonthDay.prototype.toJSON
• Temporal.PlainMonthDay.prototype.valueOf
• Temporal.PlainMonthDay.prototype.toPlainDate
• Temporal.PlainMonthDay.prototype.getISOFields (reviewed @ptomato 2022-08-03)
• Temporal.TimeZone
• Temporal.TimeZone.from
• Temporal.TimeZone.prototype.constructor (reviewed @ptomato 2022-08-03)
• Temporal.TimeZone.prototype[ @@toStringTag ] (reviewed @Ms2ger 2022-05-19)
• Temporal.TimeZone.prototype.id
• Temporal.TimeZone.prototype.getOffsetNanosecondsFor
• Temporal.TimeZone.prototype.getOffsetStringFor
• Temporal.TimeZone.prototype.getPlainDateTimeFor
• Temporal.TimeZone.prototype.getInstantFor
• Temporal.TimeZone.prototype.getPossibleInstantsFor
• Temporal.TimeZone.prototype.getNextTransition
• Temporal.TimeZone.prototype.getPreviousTransition
• Temporal.TimeZone.prototype.toString
• Temporal.TimeZone.prototype.toJSON
• Temporal.Calendar
• Temporal.Calendar.from
• Temporal.Calendar.prototype.constructor (reviewed @ptomato 2022-08-03)
• Temporal.Calendar.prototype[ @@toStringTag ] (reviewed @Ms2ger 2022-05-19)
• Temporal.Calendar.prototype.id
• Temporal.Calendar.prototype.dateFromFields
• Temporal.Calendar.prototype.yearMonthFromFields
• Temporal.Calendar.prototype.monthDayFromFields
• Temporal.Calendar.prototype.dateAdd
• Temporal.Calendar.prototype.dateUntil
• Temporal.Calendar.prototype.year
• Temporal.Calendar.prototype.month
• Temporal.Calendar.prototype.monthCode
• Temporal.Calendar.prototype.day
• Temporal.Calendar.prototype.dayOfWeek
• Temporal.Calendar.prototype.dayOfYear
• Temporal.Calendar.prototype.weekOfYear
• Temporal.Calendar.prototype.daysInWeek
• Temporal.Calendar.prototype.daysInMonth
• Temporal.Calendar.prototype.daysInYear
• Temporal.Calendar.prototype.monthsInYear
• Temporal.Calendar.prototype.inLeapYear
• Temporal.Calendar.prototype.fields
• Temporal.Calendar.prototype.mergeFields
• Temporal.Calendar.prototype.toString
• Temporal.Calendar.prototype.toJSON
• Temporal.Calendar.prototype.era
• Temporal.Calendar.prototype.eraYear
• Temporal.PlainDate.prototype.era
• Temporal.PlainDate.prototype.eraYear
• Temporal.PlainDateTime.prototype.era
• Temporal.PlainDateTime.prototype.eraYear
• Temporal.PlainYearMonth.prototype.era
• Temporal.PlainYearMonth.prototype.eraYear
• Temporal.ZonedDateTime.prototype.era
• Temporal.ZonedDateTime.prototype.eraYear"

Array.from(document.querySelectorAll('[id^="sec-temporal."], [id^="sec-get-temporal."]'))
  .map((el) => {
    return el
      .querySelector('h1')
      .innerText
      .replace(/^[0-9\. ]*(?:get )?([^ ([]+)(\[[^\]]+])?.*/, '- [ ] $1$2');
  })
  .join('\n');

Notes about specific things that should have test coverage:

• Behaviour of different rounding modes at a 0.5 boundary, for positive and negative values (from Test coverage missing for roundingMode: 'halfExpand' in since for negative numbers with 0.5 remainders proposal-temporal#1111)
• Reversibility of ZonedDateTime.p.since/until with DST changes involved (from Add test coverage for Temporal.ZonedDateTime.since/until proposal-temporal#1140). Given diffUntil = earlier.until(later, { largestUnit: 'days' }) and diffSince = later.since(earlier, { largestUnit: 'days' }), we need to test cases where:
  • diffUntil not equal to diffSince
  • earlier.add(diffUntil) equals later
  • later.subtract(diffUntil) does not equal earlier
  • later.subtract(diffSince) equals earlier
  • earlier.add(diffSince) does not equal later
  • Some of these tests may exist already in Temporal.ZonedDateTime.prototype.since/until, and in staging.
• Add more gregory calendar coverage, possibly via codegen, to check it does the same arithmetic as iso8601 for year > 1 (from Add more calendar: 'gregory' coverage to Test262 tests and/or demitasse tests proposal-temporal#1776)
• From Various bugfixes and making things consistent proposal-temporal#1393: Does Temporal check that retrieved methods from user-supplied objects are callable?
• From Various bugfixes and making things consistent proposal-temporal#1393: timeZone.getInstantFor throw for non-Temporal.Instant values
• What if calendar.fields() returns "calendar" as one of the fields? proposal-temporal#1047: calendar.fields return includes 'calendar'
• What if calendar.fields() returns "calendar" as one of the fields? proposal-temporal#1047: calendar.fields return includes non-calendar fields, e.g. 'nanoseconds'
• Temporal.now missing tests for user-supplied time zones proposal-temporal#1134: Time zones for Temporal.now()
• From Remove some internal TimeZone method calls proposal-temporal#1397: Observable lookups & calls for timeZone objects from other temporal methods
• Delegate review: Specify in which order properties are accessed when passing object to implementation-defined operation proposal-temporal#1388: Calendar order of operations (with and)? without Intl
• From Correct + make runnable documentation code samples. proposal-temporal#1396: PlainMonthDay.prototype.toPlainDate correctly handle [['year', undefined]] for input fields
• From Consume iterables where possible proposal-temporal#1489: Test CalendarFields calls, including with fields added, and getPossibleInstantsFor type checks
• Check fast-paths from delegate review: why are "Temporal-like" objects supported at all? proposal-temporal#1428:
  • PlainDateTime -> PlainTime
  • ZonedDateTime -> TimeZone
  • PlainTime -> Calendar
  • PlainDate -> relativeTo object
  • Callers of GetOptionalTemporalCalendar and ToTemporalMonthDay, with a not-previously-covered Temporal object (e.g. ToTemporalDate with some object like Object.assign(new Temporal.MonthDay(1, 1), { year: 2000 }))
  • ZonedDateTime -> PlainDate, PlainDateTime, PlainTime
• Check that with() methods don't call getters on Temporal objects
• Check all remaining callers of GetPossibleInstantsFor with checkTimeZonePossibleInstantsIterable
• Check that things of the wrong type in an iterable (calendar.fields return, calendar.fields input, timeZone.getPossibleInstantsFor return) throw before exhausting the iterator
• Check that calendar.fields is always called with the correct list of fields
• Check that Gets occur for every extra field returned by calendar.fields
• Check that toString is not called in CalendarEquals, TimeZoneEquals, ConsolidateCalendars if the two calendars are the same object (Some Calendar questions proposal-temporal#1425 point 2)
• Check that any calendar/timezone method that receives an internally-created options object, doesn't cause lookups on Object.prototype (Editor review: Kevin Gibbons proposal-temporal#1424)
• Check that property accesses on null-prototype objects created internally in Temporal don't cause lookups on Object.prototype (https://github.com/tc39/proposal-temporal/pull/1875/files#r748524136)
• Add tests for ParseTemporalDurationString overflowing one of the fields to infinity (e.g., PT99999....99999Y)
• Add tests for BalanceDuration causing a Duration field to overflow to infinity and throwing:
  • AddDuration (3x instances)
  • PlainTime.until()/since()
  • PlainDateTime.until()/since()
• Add tests for CreateDurationRecord / CreateTemporalDuration combining mixed signs or overflowing and throwing:
  • AddDateTime
  • new Temporal.Duration()
  • Duration.from()
  • Duration.with()
  • RoundDuration (3rd instance)
• Verify that there is no possible test case that would cause CreateDurationRecord / CreateTemporalDuration to combine values from different sources having different signs:
  • AdjustRoundedDurationDays (last instance)
  • AddDuration (2nd instance)
  • ZonedDateTime.until()/since()
• Verify that there is no possible test case that would cause CreateDurationRecord / CreateTemporalDuration to overflow to infinity:
  • DifferenceZonedDateTime (last instance)
  • RoundDuration
• Check that all (optionName)-undefined.js tests also test plain function objects
• Figure out a sequence of custom calendar and time zone return values that exercise the checks in Normative: Validation of NanosecondsToDays and getOffsetNanoseconds proposal-temporal#2387
• Run some DST tests against every time zone (from DST testing across many timezones? proposal-temporal#556)
• Check that a calendar annotation with an ISO date (11111111 or 1111-11-11) as the calendar name throws, and doesn't default to the ISO calendar (from Missing calendar validation in ToRelativeTemporalObject and ToTemporalZonedDateTime proposal-temporal#2546 (comment))
• Check that methods are looked up on calendar and time zone instances even if they are pristine instances of builtin calendars (this can't be tested directly but can be observed e.g. with array iteration on Calendarfields)
• Check when GetOptionsObject is performed relative to the other user-observable operations (currently this is not included in the order-of-operations.js tests) - see AddDurationToOrSubtractDurationFromPlainYearMonth: Move GetOptionsObject closer to the top proposal-temporal#2721