TypeScript 5.3 Iteration Plan

[DanielRosenwasser]

This document outlines our focused tasks for TypeScript 5.3. 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
2023-08-22	TypeScript 5.2 Release
2023-09-22	Create 5.3 Beta (5.3.0) Build for Testing
2023-09-26	TypeScript 5.3 Beta Release
2023-10-27	Create 5.3 RC (5.3.1) Build for Testing
2023-10-31	TypeScript 5.3 RC Release
2023-11-10	Create 5.3 Final (5.3.2) Build for Testing
2023-11-14	TypeScript 5.3 Final Release 🚀

gantt
    dateFormat  YYYY-MM-DD
    TypeScript 5.2 Stabilization Period : 2023-08-05, 2023-08-24
    TypeScript 5.3 Beta Development : 2023-08-05, 2023-09-22
    TypeScript 5.3 RC Development : 2023-09-23, 2023-10-27
    TypeScript 5.3 Stabilization Period : 2023-10-28, 2023-11-10
todayMarker stroke-width:5px,stroke:#0f0,opacity:0.5

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Compiler and Language

• import Attributes
• Champion throw Expressions
• Isolated Declarations
• Investigate Function Implementations Returning Indexed Access and Conditional Types
• Investigate Interop Across TypeScript and Bundlers for Default Imports
• lib.d.ts Updates

Editor and Language Service

• Interactable Inlay Type Hints
• File-Watching Events over TSServer
• Open-Ended String Completions
• Full Program Loads and ATA in vscode.dev
• Investigate AI-powered Refactorings
• Organize Imports Respecting type Imports
• Experiment with Better Names for Extracted Code
• Specify Node.js Executable for TSServer in VS Code
• Trailing Comma Completions for Snippets
• Investigate Carrying Imports Across Paste
• Address Crawler-Detected Crashes

Performance

• Investigate Parallelized Parsing
• Investigate Caching Resolutions in .tsbuildinfo
• Share Path Resolution Between Projects When Possible
• Optimize JSDoc Parsing
• Deopt Explorer Upkeep

Website and Docs

• Author and Iterate on Module Documentation
• Website Build Speedup

Community Tooling

• Investigate fetch in @types/node
• Use pnpm Workspaces in DefinitelyTyped
• Automated Formatting in DefinitelyTyped

Infrastructure

• Performance Suite Infrastructure Setup
• Expand Performance Suite
• Automated Formatting in Repo

[Andarist]

What's the current status of the "Investigate Type Argument Placeholders" item that was part of the 5.2 milestone?

[DanielRosenwasser]

I don't think we've come up with any better conclusions since the last design meeting discussion about it.

[Andarist]

Does it mean that the topic was dropped for the foreseeable future or is there a chance that it will be discussed again in the near-ish future (like in the next minor or the one after that)? I loved that the related PR (opened in 2018!) got some momentum in 5.2 and I wonder if it just got slowed down or if it stopped entirely for the time being 😅

[omermizr]

@DanielRosenwasser the timeline has wrong versions :)
Also I agree with @Andarist - this is the biggest pain point for me in TS today and would love to see it get some love <3

[DanielRosenwasser]

@DanielRosenwasser the timeline has wrong versions :)

Fixed, thanks!

Does it mean that the topic was dropped for the foreseeable future or is there a chance that it will be discussed again in the near-ish future

It's not out of the question - but big part of the iteration plans is just defining scope so the team can focus and the community gets clarity around that. They're not a promise that we'll get all the work done, nor does it guarantee other work cannot be done.

[Andarist]

That's totally understandable! I just couldn't help but notice that the other exciting item ("Investigate Function Implementations Returning Indexed Access and Conditional Types") from the 5.2 iteration plan was added here but the partial inference thing was not. Hence the question about its status cause I don't think that this investigation was concluded publicly.

[JesusTheHun]

@DanielRosenwasser What those conclusions were ? I've made a crude comment about the current proposal here.

[jiawei397]

I would like to know if there are any plans for Decorators because version 5X does not support ParameterDecorator. Also, when will the support for old version decorators be deprecated, such as the experimentalDecorators configuration?

[jakebailey]

@jiawei397 See https://github.com/tc39/proposal-decorators/blob/master/EXTENSIONS.md#parameter-decorators-and-annotations; TypeScript is just following the spec and won't add it until parameter decorators are Stage 3.

[jiawei397]

@jiawei397 See https://github.com/tc39/proposal-decorators/blob/master/EXTENSIONS.md#parameter-decorators-and-annotations; TypeScript is just following the spec and won't add it until parameter decorators are Stage 3.

Understood, thank you for your response. I will keep an eye on this progress.

[DanielRosenwasser]

@typescript-bot create release-5.3

[typescript-bot]

Heya @DanielRosenwasser, I've started to create the release-5.3 branch for you. Here's the link to my best guess at the log.

[reverofevil]

Is there a way to include this small issue into 5.3?

[DanielRosenwasser]

@typescript-bot sync release-5.3

[typescript-bot]

Heya @DanielRosenwasser, I've started to sync release-5.3 with main for you. Here's the link to my best guess at the log.

[jakebailey]

(Guess was wrong, real logs are at https://github.com/microsoft/TypeScript/actions/runs/6358420654, it did in fact run.)

[pikadun]

https://github.com/tc39/proposal-throw-expressions It still in stage 2, should it be implemented now?

[ljharb]

@pikadun stage 3 is the time to implement proposals, not 2.

[pikadun]

@ljharb Sorry, I mean it should not implement proposal-throw-expressions now, because it still Stage 2. But this version include the feature Champion throw Expressions, are they same?

[RyanCavanaugh]

Admittedly kind of confusing: The work item in the iteration plan is that we'd really like throw expressions to exist, so we're trying to get it to stage 3 so that we will then allow ourselves to implement it.

[zedryas]

@DanielRosenwasser is roadmap no longer to be edited ?
I use to love it as it is more readable for non season programmers like me ;)

[DanielRosenwasser]

I have not been able to give the roadmap page the love it deserves recently - I think our release blog posts try to give the best high-level overview of improvements, and they all contain an sort of table-of-contents at the beginning.

In the future, I'll try to get the roadmap page up to date (or others can contribute via a PR to https://github.com/microsoft/TypeScript-wiki).

[mrazauskas]

Thanks for keeping Releases section up to date.

Just a detail. 5.3 Beta should have 'Pre-release' label instead of 'Latest release'.

[jakebailey]

Oops, sorry, that was my fault. Should be fixed now.

[DanielRosenwasser]

@typescript-bot sync release-5.3

[typescript-bot]

Heya @DanielRosenwasser, I've started to sync release-5.3 with main for you. Here's the link to my best guess at the log.

[DanielRosenwasser]

@typescript-bot bump release-5.3

[typescript-bot]

Heya @DanielRosenwasser, I've started to update the version number on release-5.3 to 5.3.1-rc for you. Here's the link to my best guess at the log.

[DanielRosenwasser]

@typescript-bot sync release-5.3

[typescript-bot]

Heya @DanielRosenwasser, I've started to sync release-5.3 with main for you. Here's the link to my best guess at the log.

[acommodari]

Hey just wondering what the status is for 5.3? its already been a few days since the expected Nov 14 release and couldn't find any updates.

Thanks for all the hard work!

[HolgerJeromin]

I think they are testing latest fixes from
#56424

[kachkaev]

Can this issue be closed now, in favour of ‘TypeScript 5.4 Iteration Plan‘? The new issue does not seem to exist yet. Previous iterations:

• TypeScript 5.2 Iteration Plan #54298
• TypeScript 5.1 Iteration Plan #53031
• TypeScript 5.0 Iteration Plan #51362
• TypeScript 4.9 Iteration Plan #50457
• TypeScript 4.8 Iteration Plan #49074
• TypeScript 4.7 Iteration Plan #48027
• TypeScript 4.6 Iteration Plan #46858
• ...

Some issues labelled with Planning Iteration plans and roadmapping are closed, but this does not apply to the most recent ones. Not sure what the expected lifecycle for these.

[DanielRosenwasser]

Unfortunately I've been spread thin, but I will try to get the 5.4 iteration plan out soon.

[DanielRosenwasser]

@typescript-bot bump release-5.3

[typescript-bot]

Heya @DanielRosenwasser, I've started to update the version number on release-5.3 to 5.3.3 for you. Here's the link to my best guess at the log.

[ssalka]

Hey all, I'm just wondering if the Roadmap wiki page is still being maintained? Historically I have used that to keep up-to-date with TS developments, but recently have found myself having to inspect these iteration plan tickets.

In any case, happy to see all the new stuff coming soon to TS!

[laterdayi]

#47663 Several years later, the problem still persists

[jogibear9988]

if you parse jsdoc even in ts files #52959
isn't then #42048 an option?

[DanielRosenwasser]

The 5.4 iteration plan is now available here.