Agenda for the 90th meeting of Ecma TC39

September 24, 2025 · View on GitHub

Agenda for the 90th meeting of Ecma TC39

  • Dates and times:
    • 10:00 to 15:00 CDT (America/Chicago) on June 6th, 2022
    • 10:00 to 15:00 CDT (America/Chicago) on June 7th, 2022
    • 10:00 to 15:00 CDT (America/Chicago) on June 8th, 2022
    • 10:00 to 15:00 CDT (America/Chicago) on June 9th, 2022
  • Location: Remote
  • Attendee information: Reflector Post

For meeting times in your timezone, visit Temporal docs and run the code below in the devtools console.

Temporal.ZonedDateTime.from('2022-06-06T10:00[America/Chicago]')
  .withTimeZone(Temporal.Now.timeZone()) // your time zone
  .toLocaleString();

Background:

Agenda topic rules

Deadline for advancement eligibility: May 27th, 10:00 CDT

  • Note: this time is selected to be precisely 10 days prior to the start of the meeting
  1. Proposals not looking to advance may be added at any time; if after the deadline, please always use a pull request so that members are notified of changes. Note: an unmerged PR counts as ”added” for the purposes of this requirement.
  2. Proposals seeking feedback at stage 0 must be added (and noted as such) prior to the deadline, or else delegates may object to advancement solely on the basis of missing the deadline.
    1. Such proposals should include supporting materials when possible.
  3. Proposals looking to advance to stage 1 must be added (and noted as such) prior to the deadline, or else delegates may object to advancement solely on the basis of missing the deadline.
    1. Such proposals must link to a proposal repository and they should link to supporting materials when possible.
  4. Proposals looking to advance to stages 2, 3, or 4 must be added (and noted as such) along with the necessary materials prior to the deadline, or else delegates may object to advancement solely on the basis of missing the deadline.
    1. Such proposals must link to supporting materials prior to the deadline, or else delegates may object to advancement solely on the basis of missing the deadline. If these materials change substantially after the deadline, the proposal may be disqualified from advancement, based on the committee’s judgment.
    2. Proposals looking to advance to stage 4 must link to a pull request into the spec, since the process requires one.
  5. Proposal-based agenda items should be sorted primarily by stage (descending), secondarily by timebox (ascending), and finally by insertion date.

Supporting materials includes slides, a link to the proposal repository, a link to spec text, etc.; essentially, anything you are planning to present to the committee, or that would be useful for delegates to review.

Agenda items

  1. Opening, welcome and roll call (Chair)

    1. Opening of the meeting
    2. TC39 follows its Code of Conduct
    3. Introduction of attendees
    4. Host facilities, local logistics
    5. Quick recap of meeting IPR policy
    6. Overview of communication tools

  2. Find volunteers for note taking

  3. Adoption of the agenda

  4. Approval of the minutes from last meeting

  5. Next meeting host and logistics

  6. Secretary's Report (15m, Istvan Sebestyen) https://github.com/tc39/agendas/blob/HEAD/2022/tc39-2022-022_draft.pdf

  7. Project Editors’ Reports

    1. ECMA262 Status Updates (slides) (15m)
    2. ECMA402 Status Updates (15m)
    3. ECMA404 Status Updates (15m)
    4. Test262 Status Updates (slides) (15m)

  8. Updates from the CoC Committee (15m)

  9. Web compatibility issues / Needs Consensus PRs

    ✓timeboxtopicpresenter
    25mWhat did we decide for #1556? I don't remember. :(Shu-yu Guo
    30mWhere do you get your default time zone? (slides)Richard Gibson
    45mRemove Job from Promise Resolve Functions (slides)Justin Ridgewell

  10. Overflow from previous meeting

    ✓timeboxtopicpresenter

  11. Incubation call chartering (15m on the last day)

  12. Short (≤30m) Timeboxed Discussions

    ✓timeboxtopicpresenter

  13. Proposals

    ✓ represents an agenda item which has been presented, and does not indicate stage advancement

    ✓stagetimeboxtopicpresenter
    310mArray Grouping rename groupBy to groupJustin Ridgewell
    310mfindLast/findLastIndex for stage 4 (slides)Daniel Rosenwasser
    310m⏳ Decorators Normative Change: Flexible Initializers (slides)Kristen Hewell Garrett
    315mShadowRealm: Implementation Status and normative updates, (slides TBD)Leo Balter, Rick Waldron, Caridy Patiño, John-David Dalton
    330mErrors across the ShadowRealm boundaryShu-yu Guo
    330mTemporal normative changes (slides)Ujjwal Sharma
    310mMaking TypedArray.prototype.with simpler in the change Array by copy proposal (issue)Shu-yu Guo
    330m⏳ Intl.DurationFormat stage 3 update (slides)Ujjwal Sharma
    230mSymbols as WeakMap keys for stage 3 [spec] [slides] [diff]Ashley Claymore, Robin Ricard
    230mfunction.sent update slidesHE Shi-Jun
    230mRegExp Modifiers for Stage 3? (spec, slides, pending reviews)Ron Buckton
    230mJSON.parse source text access for Stage 3 (spec, slides)Richard Gibson
    130mString.dedent for stage 2 (draft spec, slides)Justin Ridgewell
    160mGrouped and Auto-Accessors for stage 2 (draft spec, slides)Ron Buckton
    160mImport Reflection status update & discussion (slides)Guy Bedford & Luca Casonato
    030mDuplicate named capture groups for stage 1, 2, or 3Kevin Gibbons
    030mthis parameter for Stage 1, slidesHE Shi-Jun
    060mRegExp Atomic Operators for Stage 1 (draft spec, slides)Ron Buckton

  14. Longer or open-ended discussions

    ✓timeboxtopicpresenter

  15. Overflow from timeboxed agenda items (in insertion order)

    ✓topicpresenter

  16. Other business

    1. Thank host

  17. Adjournment

Schedule constraints

  • Leo Balter (Salesforce) not available on June 8th and 9th. Not required but would like to attend any ShadowRealms topics and Symbols as WeakMap Keys for stage 3.
  • Ashley Claymore (Bloomberg) (co-presenter for Symbols as WeakMap keys topic) not available on June 8th after 11:30 EDT.
  • Jordan Harband (Coinbase) will not be available on June 8th after 2PM local time, and would prefer to be present for Array Grouping, findLast, Symbols as WeakMap keys, function.sent, RegExp Modifiers, JSON.parse source text access, dedent, auto-accessors, Duplicate Named Capture Groups, Fatal Errors
  • Michael Saboff (Apple) will not be available the second half of June 6th.

Dates and locations of future meetings

DatesLocation
2022-07-18 to 2022-07-21San Francisco, CA
2022-09-13 to 2022-09-16Tokyo, Japan