TypeScript 5.5 Iteration Plan #57475

DanielRosenwasser · 2024-02-22T00:54:09Z

This document outlines our focused tasks for TypeScript 5.5. 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
2024-03-05	TypeScript 5.4 Release
2024-04-19	Create 5.5 Beta (5.5.0) Build for Testing
2024-04-24	TypeScript 5.5 Beta Release
2024-05-31	Create 5.5 RC (5.5.1) Build for Testing
2024-06-04	TypeScript 5.5 RC Release
2024-06-14	Create 5.5 Final (5.5.2) Build for Testing
2024-06-18	TypeScript 5.5 Final Release 🚀

gantt
    dateFormat  YYYY-MM-DD
    TypeScript 5.4 Stabilization Period : 2024-02-16, 2024-03-05
    TypeScript 5.5 Beta Development : 2024-02-16, 2024-04-19
    TypeScript 5.5 RC Development : 2024-04-20, 2024-05-31
    TypeScript 5.5 Stabilization Period : 2024-06-01, 2024-06-18
todayMarker stroke-width:5px,stroke:#0f0,opacity:0.5

Compiler and Language

Editor and Language Service

Performance

More Caching in --incremental Mode
Improved Performance for Git Branch Switching Scenarios
Investigate Running With V8 Snapshots

Website and Docs

Simplify and Refactor Website for Faster Builds

Infrastructure

Adopt --isolatedDeclarations and Parallelize TypeScript's Build

The text was updated successfully, but these errors were encountered:

DanielRosenwasser · 2024-02-22T00:55:01Z

The previous iteration plan is available here.

kevinbarabash · 2024-02-25T23:42:29Z

How much of an impact will --isolatedDeclarations have on type checking performance in large projects?

jakebailey · 2024-02-26T00:43:46Z

None directly, in the same way that isolatedModules doesn't speed things up in and of itself.

But, if you have code which passes isolatedModules, it can be safely transpiled by an external tool (like Babel, esbuild, swc). And similarly, code passing isolatedDeclarations can be transpiled into a declaration file by an external tool too (once one exists).

jakebailey · 2024-02-26T00:45:12Z

(This isn't to say that there can't be some speedups possible in TypeScript in the future enabled by this option, just that the flag itself is intended to just be checks.)

JVKdouk · 2024-03-01T04:47:02Z

Hey everyone, any chance of getting #26242 in this release? It was proposed back in 2018 and there has not been much work on the issue up to this point. Getting it at least planned would already be amazing to the TS community. I believe it would substantially improve the power of TS in the long run!

ClearedFram3 · 2024-03-01T18:33:09Z

Just a heads up, I'm working on remaking the website using Sveltekit. Styles will be the same, but the overall structure will be simpler and much quicker to iterate on.

DanielRosenwasser · 2024-03-01T18:43:17Z

@ClearedFram3 while I don't want to discourage experimentation, I don't think we would accept such a large PR without discussing changes ahead of time.

ClearedFram3 · 2024-03-02T00:39:21Z

@DanielRosenwasser I should've said the codebase structure will be different—the website style/content structure will be the same. After the current codebase is replaced, there will ample room for discussion about changing design and content or even to a different framework haha.

graphemecluster · 2024-03-07T16:55:18Z

I’ve been watching the iteration plan threads from 5.4 seeing my PR (#55600) on the list. I am on standby anytime for any necessary alternations.

jwalkerinterpres · 2024-03-07T18:54:40Z

Is there anything Typescript community members can do to influence this list?

I think I can speak for every TS React dev on the planet when I say that #29526 (improved syntax for destructuring an argument ... like the React props argument) has languished long enough. The community has essentially reached a consensus on a desired syntax in that ticket (something that was not easy), and now all that's needed is developer will to implement.

I can't speak for anyone else, but personally I would trade everything on the 5.5 list for this one feature!

aspirisen · 2024-03-16T08:41:38Z

A question about Investigate Recursive Object Type References
Will it help i.e. in zustand in avoiding writing interface for the state, and instead just infer the type from the initial state (create-function argument)?

jcalz · 2024-03-20T18:22:04Z

Allow Implementing Functions That Return Conditional Types

Cross-linking #33912 and #56941

narcis-ro · 2024-04-02T17:18:37Z

Is there any chance after 10 years.. to introduce nameof?

Is it super complicated? Honest question

#1579

DanielRosenwasser · 2024-04-02T20:28:52Z

@typescript-bot bump release-5.4

typescript-bot · 2024-04-02T20:28:55Z

Starting jobs; this comment will be updated as builds start and complete.

Command	Status	Results
`bump release-5.4`	✅ Started	✅ Results

typescript-bot · 2024-04-02T20:38:08Z

Hey, @DanielRosenwasser! I've set the version of release-5.4 to 5.4.4 for you.

DanielRosenwasser · 2024-04-09T22:05:26Z

@typescript-bot bump release-5.4

typescript-bot · 2024-04-09T22:05:29Z

Starting jobs; this comment will be updated as builds start and complete.

Command	Status	Results
`bump release-5.4`	✅ Started	✅ Results

DanielRosenwasser · 2024-04-09T22:13:24Z

Whoops - I've been posting in the wrong iteration plan. Sorry for the noise folks.

typescript-bot · 2024-04-09T22:14:17Z

Hey, @DanielRosenwasser! I've set the version of release-5.4 to 5.4.5 for you.

WORMSS · 2024-04-11T09:26:17Z

I think I can speak for every TS React dev on the planet when I say that #29526 (improved syntax for destructuring an argument ... like the React props argument) has languished long enough.

I can't disagree more with all existing proposals in #29526. It will make TypeScript syntax very confusing.

This is the first I am hearing about this.. (I guess I've had my head in the sand for a while).. We already have a solution to this.. ({ a, b }: SomeType) => void.. This makes sense, and already works..
This sounds like a massive problem waiting to happen if this gets implemented the way people are saying.

This type of stuff is going to push the whole "Javascript can run TS script directly, but just ignoring the types" concept even FURTHER AWAY!
It seems like shooting yourself in the foot to try and solve something that is already solved.

snarbies · 2024-04-11T12:36:58Z

But it's important to consider different voices.

Then why not add your voice to that issue? Respond to the arguments and examples presented there, there.

This type of stuff is going to push the whole "Javascript can run TS script directly, but just ignoring the types" concept even FURTHER AWAY!

Again, if you join the actual discussion you can respond to people who are addressing this exact concern (#29526 (comment)). The only argument I see in that issue is that the double-colon syntax may actually benefit this cause. If there's an argument to the contrary, you should make it there so it can be properly considered.

jwalkerinterpres · 2024-04-11T15:19:05Z

We already have a solution to this.. ({ a, b }: SomeType) => void

Most devs believe in the "DRY principle". When you use the syntax you mentioned, it's not DRY code; you have ({ a, b }: {a: someType; b:someType) => void (where a and b are needlessly repeated).

#29526 is simply about eliminating duplication, nothing more. There are already 30+ devs participating in that discussion (and who knows how many are lurking), all because they want to see that duplication eliminated.

If you have something against eliminated duplication, by all means respond ... in that ticket. This thread is not the appropriate place to discuss any particular ticket.

DanielRosenwasser · 2024-04-12T21:06:15Z

For anyone here for the iteration plan: we are going to push the beta out about a week to make sure we can bring in some scheduled work.

DanielRosenwasser · 2024-04-24T06:53:14Z

@typescript-bot create release-5.5

typescript-bot · 2024-04-24T06:53:17Z

Starting jobs; this comment will be updated as builds start and complete.

Command	Status	Results
`create release-5.5`	❌ Error: HttpError: Unexpected inputs provided: ["core_tag"] - https://docs.github.com/rest/actions/workflows#create-a-workflow-dispatch-event

DanielRosenwasser · 2024-04-24T06:53:43Z

No, bad.

DanielRosenwasser · 2024-04-24T07:03:33Z

Jake says he fixed it. @typescript-bot tell @jakebailey thank you and also

@typescript-bot create release-5.5

typescript-bot · 2024-04-24T07:03:36Z

Starting jobs; this comment will be updated as builds start and complete.

Command	Status	Results
`create release-5.5`	✅ Started	❌ Results

typescript-bot · 2024-04-24T07:14:15Z

Hey, @DanielRosenwasser! I was unable to create the new release branch.

Check the logs at: https://github.com/microsoft/TypeScript/actions/runs/8812429335

WORMSS · 2024-04-24T07:16:58Z

Surely there is a better way to interact with a bot than to have multiple people emailed about every request and then every response?

Aloso · 2024-04-24T16:29:40Z

@WORMSS but you can disable notifications for this thread, if you don't want to be notified about new activity.
The bot exists to help contributors, who do want to get notified about messages from the bot.

WORMSS · 2024-04-24T16:31:16Z

I don't mind getting notifications.. don't want to get a notification about people talking TO the bot..

Aloso · 2024-04-24T16:35:56Z

GitHub doesn't provide such a feature. And I don't understand your complaint, it is just a minor inconvenience for you, but a big help for contributors.

DanielRosenwasser · 2024-04-25T21:38:07Z

Hey all, 5.5 Beta is now out!

Blog post: https://devblogs.microsoft.com/typescript/announcing-typescript-5-5-beta/
Release tag: https://github.com/microsoft/TypeScript/releases/tag/v5.5-beta

Jack-Works · 2024-04-26T07:06:11Z

for anyone founding their .d.ts file augmentation no longer working (a breaking change not mentioned in the blog), see #58324

DanielRosenwasser added the Planning Iteration plans and roadmapping label Feb 22, 2024

DanielRosenwasser pinned this issue Feb 22, 2024

sandersn mentioned this issue Mar 1, 2024

Intl.NumberFormat: missing options, and discussion on typing conventions #56269

Closed

This was referenced Mar 27, 2024

support @import from TypeScript 5.5 gajus/eslint-plugin-jsdoc#1218

Closed

TypeScript 5.5 with @import tag Agoric/agoric-sdk#9149

Merged

inoyakaigor mentioned this issue Apr 2, 2024

Supporting a new set methods mobxjs/mobx#3853

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nyngwang mentioned this issue Apr 12, 2024

Easier destructuring with type annotations on binding patterns #29526

Open

5 tasks

karlhorky mentioned this issue Apr 19, 2024

Add template variable ${configDir} (name to be determined) for file path substitution #57485

Closed

6 tasks

DanielRosenwasser mentioned this issue Apr 24, 2024

Disable no-inferrable-types eslint rule #58306

Merged

merceyz mentioned this issue Apr 25, 2024

Test Node 22 #58309

Merged

TypeScript 5.5 Iteration Plan #57475

TypeScript 5.5 Iteration Plan #57475

Comments

DanielRosenwasser commented Feb 22, 2024 • edited

Compiler and Language

Editor and Language Service

Performance

Website and Docs

Infrastructure

DanielRosenwasser commented Feb 22, 2024 • edited

kevinbarabash commented Feb 25, 2024

jakebailey commented Feb 26, 2024

jakebailey commented Feb 26, 2024

JVKdouk commented Mar 1, 2024 • edited

ClearedFram3 commented Mar 1, 2024

DanielRosenwasser commented Mar 1, 2024 • edited

ClearedFram3 commented Mar 2, 2024

graphemecluster commented Mar 7, 2024 • edited

jwalkerinterpres commented Mar 7, 2024 • edited

aspirisen commented Mar 16, 2024

jcalz commented Mar 20, 2024

narcis-ro commented Apr 2, 2024

DanielRosenwasser commented Apr 2, 2024

typescript-bot commented Apr 2, 2024 • edited

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DanielRosenwasser commented Apr 9, 2024

typescript-bot commented Apr 9, 2024 • edited

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WORMSS commented Apr 11, 2024

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Jack-Works commented Apr 26, 2024

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