Andrew Branch
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andrewbran.ch
Andrew Branch
@andrewbran.ch
1.1K followers 100 following 51 posts
Working on TypeScript at Microsoft. I appear when someone says “module resolution” three times in the dark. He/him
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Reposted by Andrew Branch
remcohaszing.nl
I published a TypeScript content mapper for CSS modules. This gives you type-safety and definitions when importing CSS in TypeScript.

github.com/remcohaszing...
On the right is a pane of CSS code. On the left is a pane of TypeScript code that imports the CSS as a module. The hover info of the imported CSS class shows the CSS block. There’s also an unknown class name, which has a red squiggly underline.
September 6, 2026 at 9:10 AM
Reposted by Andrew Branch
chenjiahan.bsky.social
Excited that TypeScript will finally support module types based on import attributes!

Bundlers and frameworks can now provide accurate types for custom imports:
September 1, 2026 at 4:06 AM
Reposted by Andrew Branch
nullvoxpopuli.com
Ember now has preliminary TS7 support
~ via the content-mappers feature that merged in TS last week

Testers wanted!

(requires TS Nightly)
August 26, 2026 at 2:34 AM
Reposted by Andrew Branch
chenjiahan.bsky.social
The TypeScript content mappers PR just merged and is likely to land in 7.1 🎉

This could open a new chapter for everything built on and around TypeScript

github.com/microsoft/ty...
Content mappers by andrewbranch · Pull Request #4712 · microsoft/typescript-go
Implements microsoft/TypeScript#63800 (comment) Overview Content mappers are external integrations that allow TypeScript to include otherwise unsupported file types in a program. They transform a f...
github.com
August 20, 2026 at 11:34 AM
Reposted by Andrew Branch
remcohaszing.nl
My editor using mdx-content-mapper is now showing TypeScript info for frontmatter and code blocks.
An MDX file with two JavaScript code blocks. One is hovered and shows information about the code. The other highlights a type error. An MDX file with YAML frontmatter data and a variable named frontmatter. Hover information for the frontmatter variable shows the TypeScript type of the frontmatter data.
August 17, 2026 at 7:49 PM
andrewbran.ch
If you’re not stalking TypeScript PRs, you might be surprised how much you can do with the API in nightlies (and even in 7.0 stable), so here’s a tiny demo that I think hits some of the highlights. 🧵
A package.json in VS Code after npm installing typescript@next
August 15, 2026 at 2:05 AM
Reposted by Andrew Branch
johnnyreilly.com
I've been busy experimenting with the new emit APIs that TypeScript 7.1 will bring. ts-loader now has basic support in place - here's how we got there!

johnnyreilly.com/migrating-ts...
Migrating ts-loader to TypeScript 7.1 with AI
How I used AI to migrate ts-loader to TypeScript 7.1.
johnnyreilly.com
July 31, 2026 at 3:16 PM
Reposted by Andrew Branch
dsherret.dev
ts-ast-viewer.com now supports TypeScript 7 along with nightly builds of the typescript-go repository. It's not selected by default, but available in the dropdown.
Dropdown menu showing a TypeScript 7.0.2 selection on ts-ast-viewer.com
July 30, 2026 at 2:46 PM
Reposted by Andrew Branch
johnnyreilly.com
If you discount project references (and there's no API support as yet I believe), then all bar around 6 tests of ts-loader are now passing using the 7.1 tsgo TypeScript API! Not quite there yet but significant progress

github.com/TypeStrong/t...
Support TypeScript 7.1 API by Copilot · Pull Request #1704 · TypeStrong/ts-loader
This PR is an attempt at using the TypeScript 7.1+ API. This pares back the earlier tsgo integration attempt to the new API alone. Instead of carrying both implementations, experimentalNativeApi no...
github.com
July 28, 2026 at 4:36 PM
Reposted by Andrew Branch
johnnyreilly.com
Building upon the fine work of @pier.fumagalli.org / @titiancernicova.bsky.social / @andrewbran.ch I've been throwing copilot at the new TypeScript 7.1 API and ts-loader. Very early days but some progress!

github.com/TypeStrong/t...
Add minimal experimental tsgo transpile path by Copilot · Pull Request #1704 · TypeStrong/ts-loader
This pares back the earlier tsgo integration attempt to the new API alone. Instead of carrying both implementations, experimentalNativeApi now routes through the tsgo API directly, with the existin...
github.com
July 27, 2026 at 11:36 AM
Reposted by Andrew Branch
mary.my.id
they coulda trained opus 5 to learn that typescript 7 is stable now because it simply refuses to believe oxlint with type checking enabled only takes 28ms to run
July 25, 2026 at 1:37 PM
Reposted by Andrew Branch
pier.fumagalli.org
Today’s Typescript 7 daily release finally includes my contribution to support “emit” via API!

Right before the weekend, so I can waste it playing around with it 😛

Thanks @andrewbran.ch tor including it!

npmx.dev/package-code...
Code - [email protected] - npmx
Browse source code for [email protected]
npmx.dev
July 25, 2026 at 11:02 AM
Reposted by Andrew Branch
typescriptlang.org
📣 The moment is here. 📣

TypeScript 7 is officially released! 7️⃣

devblogs.microsoft.com/typescript/a...
Announcing TypeScript 7.0 - TypeScript
Today we are proud to announce the availability of TypeScript 7, a 10x faster native port of TypeScript! Since its early days, TypeScript has promised to
devblogs.microsoft.com
July 8, 2026 at 4:22 PM
Reposted by Andrew Branch
ashley-c.bsky.social
I've been experimenting with having `ts-blank-space` use the (unstable) TypeScript-go JS API.

At first it was ~60% slower than using the TS 6 API, but with a bit of investigation, a bug fix, and a small refactor to use different API calls it is now ~24% faster!

Draft PR: github.com/bloomberg/ts...
Terminal output of running ts-blank-space's `./bench.sh` script. TS go has a mean of 972 milliseconds (+/- 7ms). TS 6 has a mean of 1205 milliseconds (+/- 8ms). So TS go ran 1.24 times faster.
July 5, 2026 at 3:23 PM
Reposted by Andrew Branch
jakebailey.dev
My talk was accepted to GopherCon 2026 in Seattle!

I'm back with more TypeScript+Go goodness, this time with another year's worth of experience under our belt.

I had a blast at last year's conference, so here's to yet another one!

www.gophercon.com/agenda/speak...
Jake Bailey Principal Software Engineer Microsoft Jake is a programming language lover and Principal Software Engineer at Microsoft. He currently works on TypeScript, mainly focusing on performance, infrastructure, and the ecosystem, along with side adventures in Go (especially compiler and runtime changes in Go and TinyGo!). Blog: jakebailey.dev SESSIONS Wed Aug 05, 5:15 PM - 5:40 PM PDT (25 min) State of TypeScript 7: Beyond the Port - Speaker Last year, we shared the story of TypeScript's port to Go. A lot has happened since then: we've shipped TypeScript 6.0 as a bridge release, watched our native preview grow past 5 million weekly downloads. The port is done, but the work didn't stop there. In this talk, we'll go beyond the port itself. We'll cover the new API surfaces we've built on top of the Go codebase, including a snapshot-based language server, cross-language IPC, and Wasm. We'll talk about how the community has adopted the new compiler, how we've ensured stability at scale, and what surprises and compromises came up along the way. We'll also share our continued experience writing Go; where the language and toolchain have gotten better for us, and where they sometimes haven't. Talk/Attendee Level: Intermediate Finneran Ballroom 2, Level 5, SCC | Summit
May 6, 2026 at 1:00 AM
Reposted by Andrew Branch
typescriptlang.org
TypeScript 6.0 is now available!

This release brings better type-checking for methods, new standard library features, new module features for Node.js, and more!

But most important, this release brings us one step closer to the upcoming native-speed 7.0!

devblogs.microsoft.com/typescript/a...
Announcing TypeScript 6.0 - TypeScript
TypeScript 6.0 is now available! TypeScript 6 is a stepping-stone release, aligning with the upcoming native-speed 7.0 release.
devblogs.microsoft.com
March 23, 2026 at 4:53 PM
Reposted by Andrew Branch
joyeecheung.bsky.social
Finished two retrospective blog posts on the journey of require(esm) before 2025 ends:

joyeecheung.github.io/blog/2025/12...

joyeecheung.github.io/blog/2025/12...
require(esm) in Node.js: from experiment to stability
More than a year ago, I set out to revive require(esm) in Node.js and landed an experimental implementation. After a lot of iteration and battle-testing, require(esm) is now unflagged across all suppo
joyeecheung.github.io
December 30, 2025 at 7:04 PM
Reposted by Andrew Branch
typescriptlang.org
Big news in this year's GitHub Octoverse report: TypeScript is now the most-used language on GitHub!

We are thrilled and grateful to see the TypeScript and JavaScript community continue to grow and thrive. 🚀

Read up more at github.blog/news-insight...
Octoverse: A new developer joins GitHub every second as AI leads TypeScript to #1
In this year’s Octoverse, we uncover how AI, agents, and typed languages are driving the biggest shifts in software development in more than a decade.
github.blog
October 28, 2025 at 6:47 PM
Reposted by Andrew Branch
jakebailey.dev
Tonight will be one of the best nightlies of the TypeScript Native Preview ever.

1) @andrewbran.ch fully rewrote the language server infra into a snapshot model. No more data races. It's so cool

2) Sheetal added build mode (-b), and it's even _concurrent_ build mode. 10x+ on dt-tools, hot and cold
Benchmark 1: node ./node_modules/typescript/lib/tsc.js -b . -f Time (mean ± σ): 4.204 s ± 0.057 s [User: 6.437 s, System: 0.533 s] Range (min … max): 4.142 s … 4.305 s 10 runs Benchmark 2: /home/jabaile/work/TypeScript-go/built/local/tsgo -b . -f Time (mean ± σ): 377.8 ms ± 8.1 ms [User: 2827.7 ms, System: 453.3 ms] Range (min … max): 361.4 ms … 387.1 ms 10 runs Summary /home/jabaile/work/TypeScript-go/built/local/tsgo -b . -f ran 11.13 ± 0.28 times faster than node ./node_modules/typescript/lib/tsc.js -b . -f Benchmark 1: node ./node_modules/typescript/lib/tsc.js -b . Time (mean ± σ): 1.247 s ± 0.016 s [User: 1.859 s, System: 0.252 s] Range (min … max): 1.232 s … 1.284 s 10 runs Warning: Statistical outliers were detected. Consider re-running this benchmark on a quiet system without any interferences from other programs. It might help to use the '--warmup' or '--prepare' options. Benchmark 2: /home/jabaile/work/TypeScript-go/built/local/tsgo -b . Time (mean ± σ): 120.6 ms ± 9.5 ms [User: 843.1 ms, System: 207.4 ms] Range (min … max): 111.8 ms … 156.0 ms 24 runs Summary /home/jabaile/work/TypeScript-go/built/local/tsgo -b . ran 10.34 ± 0.82 times faster than node ./node_modules/typescript/lib/tsc.js -b .
August 21, 2025 at 11:39 PM
Reposted by Andrew Branch
typescriptlang.org
Today we're announcing previews of the native port of TypeScript! These nightly previews will be available on npm and the VS Code marketplace!

npm install -D @​typescript/native-preview
npx tsgo --version

Read up more on our blog!
Announcing TypeScript Native Previews - TypeScript
Previews of the native TypeScript port are now available on npm and for VS Code through the Visual Studio Marketplace!
devblogs.microsoft.com
May 22, 2025 at 3:09 PM
Reposted by Andrew Branch
typescriptlang.org
Today we're thrilled to announce our effort to port the TypeScript compiler and language service to native code, gaining a 10x speed boost in build times and editor responsiveness!

devblogs.microsoft.com/typescript/t...
A 10x Faster TypeScript - TypeScript
Embarking on a native port of the existing TypeScript compiler and toolset to achieve a 10x performance speed-up.
devblogs.microsoft.com
March 11, 2025 at 2:36 PM
Reposted by Andrew Branch
jakebailey.dev
It hasn't happened yet (merging today!!!), but I wrote a big ol blog post on the giant migration of DefinitelyTyped to a @pnpm.bsky.social monorepo! I am super excited for this. Again thank you @andrewbran.ch, Nathan, @zkochan.bsky.social and everyone else.

jakebailey.dev/posts/pnpm-d...
DefinitelyTyped is a monorepo!
Yes, it is! But for real this time!
jakebailey.dev
October 17, 2023 at 6:45 PM
Reposted by Andrew Branch
jakebailey.dev
Next week is gonna be a fun week

Soon the scourge of baseUrl, paths, and typesRoot will be purged, replaced with "how about we actually use node_modules like everyone else"

(thank you Andrew and Nathan for your efforts, and of course @zkochan.bsky.social and contributors for pnpm)
Screen shot of the WIP PR to DefinitelyTyped which will convert it into a pnpm monorepo
October 14, 2023 at 12:00 AM
Reposted by Andrew Branch
typescriptlang.org
The Release Candidate of TypeScript 5.2 is now out to try! Test it out and let us know if you run into any issues!
Announcing TypeScript 5.2 RC - TypeScript
Today we’re excited to announce our Release Candidate of TypeScript 5.2! Between now and the stable release of TypeScript 5.2, we expect no further changes apart from critical bug fixes. To get star...
devblogs.microsoft.com
August 9, 2023 at 8:23 PM
Reposted by Andrew Branch
typescriptlang.org
We just released TypeScript 5.2 Beta! Check out

- 'using' Declarations
- Decorator Metadata
- Easier Tuple Type Notation
- Inline Variable Refactoring
- Comma Completions in Objects

and more! Try it today!
Announcing TypeScript 5.2 Beta - TypeScript
Today we are excited to announce the availability of TypeScript 5.2 Beta. To get started using the beta, you can get it through NuGet, or through npm with the following command: npm install -D typescr...
devblogs.microsoft.com
June 30, 2023 at 5:51 PM