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TypeScript 4.9 Iteration Plan #50457
Description
This document outlines our focused tasks for TypeScript 4.9. It minimally indicates intent to investigate tasks or contribute to an implementation. Nothing is set in stone, but we will strive to complete these tasks in a reasonable timeframe.
| Date | Event |
|---|---|
| August 23rd | TypeScript 4.8 Release |
| September 16th | Create 4.9 Beta (4.9.1) Build for Testing |
| September 20th | TypeScript 4.9 Beta Release |
| October 28th | Create 4.9 RC (4.9.2) Build for Testing |
| November 1st | TypeScript 4.9 RC Release |
| November 11th | Create 4.9 Final (4.9.3) Build for Testing |
| November 15th | TypeScript 4.9 Final Release 🚀 |
gantt
dateFormat YYYY-MM-DD
TypeScript 4.8 Stabilization Period : 2022-08-05, 2022-08-25
TypeScript 4.9 Beta Development : 2022-08-05, 2022-09-16
TypeScript 4.9 RC Development : 2022-09-16, 2022-10-28
TypeScript 4.9 Stabilization Period : 2022-10-28, 2022-11-15
todayMarker stroke-width:5px,stroke:#0f0,opacity:0.5
Language and Compiler Features
- ECMAScript Decorators
- Contextually Typed And Compatible Operator
lib.d.tsUpdates- Support
.tsas a Module Specifier for Bundler/Loader Scenarios - Investigate Fine-Granularity Module Resolution Options
- Investigate Per-File Settings
- Make @types/web Versionable
- Investigate
--isolatedDeclarationEmit Mode
Editor Productivity
- Switch to FsEvents for File-Watching by Default
- Virtual File System Support in TSServer
- Investigate Cancellation in Browser Contexts
- Prototype Automatic Type Acquisition in Web Contexts
- Investigate TS Server Plugins on the Web
- High Confidence JavaScript Diagnostics in Classes
- Provide Walkthroughs in Visual Studio Code Welcome View
- Easy Run/Debug for Loose TypeScript Files
Performance
- Investigate Module Resolution Caching in
.tsbuildinfoFiles - Investigate Tooling for JIT Deoptimizations
- Investigate Outstanding Performance Issues
- Enrich TS Server Tracepoints
Infrastructure
- Enable
strictFunctionTypeson TypeScript Codebase - Determining Module Migration and Shipping Strategy
- Rewrite TSServer Crawler
- TSServer Performance Testing Infrastructure
Activity
DanielRosenwasser commentedon Aug 25, 2022
Previous iteration plan is over at #49074
DanielRosenwasser commentedon Sep 16, 2022
Looks like we may be adjusting the beta deadline to early next week to get in a few PRs that needed to wait as a result of 4.8 servicing tasks.
DanielRosenwasser commentedon Sep 21, 2022
TypeScript Bot (@typescript-bot) create release-4.9
typescript-bot commentedon Sep 21, 2022
Heya Daniel Rosenwasser (@DanielRosenwasser), I've started to create the
release-4.9branch for you. Here's the link to my best guess at the log.DanielRosenwasser commentedon Sep 21, 2022
A few updates:
.tsbuildinfofiles is still in flux. We'll likely have to decide on that only if we feel like we can get sufficient coverage.DanielRosenwasser commentedon Sep 21, 2022
TypeScript Bot (@typescript-bot) create release-4.9
typescript-bot commentedon Sep 21, 2022
Heya Daniel Rosenwasser (@DanielRosenwasser), I've started to create the
release-4.9branch for you. Here's the link to my best guess at the log.DanielRosenwasser commentedon Sep 22, 2022
TypeScript Bot (@typescript-bot) sync release-4.9
typescript-bot commentedon Sep 22, 2022
Heya Daniel Rosenwasser (@DanielRosenwasser), I've started to sync
release-4.9with main for you. Here's the link to my best guess at the log.DanielRosenwasser commentedon Sep 23, 2022
Due to #50927, the correct beta on npm is 4.9.1-beta. The RC will be 4.9.2-rc. The stable will be 4.9.3.
One day we will be able to avoid incrementing the patch and just publish pre-releases.
fatcerberus commentedon Sep 23, 2022
I always thought it was weird that TS prereleases consume entire version numbers. What is the technical reason for that?
jakebailey commentedon Sep 23, 2022
Something to do with places like the VS Marketplace which don't support prerelease tags, though that might have changed entirely. https://github.com/microsoft/TypeScript/wiki/TypeScript's-Release-Process#why-do-you-need-to-set-the-patch-version-on-pre-releases
Maybe things have changed enough such that we can do something different now.
xiaoxiangmoe commentedon Sep 27, 2022
Will per-file settings available in ts 4.9? Or maybe move it to 5.0?
chriskrycho commentedon Oct 18, 2022
👋🏼 In Ember.js' testing against TS, we noted failures against 4.9 starting with the
4.9.0-dev.20221014release. I believe these are legitimate issues (the fix here is demonstrably all sorts of unsafe!), but the underlying change wasn't called out in the 4.9 blog post, so I wanted to flag it here as a thing to possibly mention – I assume this was a case of intersection handling andunknowngetting better.DanielRosenwasser commentedon Oct 30, 2022
TypeScript Bot (@typescript-bot) sync release-4.9
typescript-bot commentedon Oct 30, 2022
Heya Daniel Rosenwasser (@DanielRosenwasser), I've started to sync
release-4.9with main for you. Here's the link to my best guess at the log.jakebailey commentedon Oct 30, 2022
I feel like we need to add
-X theirsto that workflow's merge so that it always takes what's inmain(kinda likereset --hard mainbut without breaking history). Unfortunate that we hit conflicts thanks to LKG changing in both.DanielRosenwasser commentedon Nov 1, 2022
The 5.0 iteration plan is over at #51362.
DanielRosenwasser commentedon Dec 5, 2022
TypeScript Bot (@typescript-bot) bump release-4.9
typescript-bot commentedon Dec 5, 2022
Heya Daniel Rosenwasser (@DanielRosenwasser), I've started to update the version number on
release-4.9to4.9.4for you. Here's the link to my best guess at the log.