Your TypeScript year in review You "silenced" 417 errors with `as any` that turned into runtime errors as soon as the code ran TypeScript printed 4,693 error messages. 26 of them made sense You spent 98 minutes waiting for tsc to run. During this time you spent 544 minutes reading social media

Cannot wait to play Doom in TypeScript on the Sega Dreamcast github.com/drpaneas/lib...

👋 Hi! For those unfamiliar I'm Hawk, a UX Engineer on the @vscode.dev team. As 2025 comes to a close, I've been wanting to get a pulse on how folks are writing code. Genuinely curious: What tool(s) do you use? What do you like/dislike about them? What do you wish your tool could do that it doesn't?

My regular PSA that if you enjoy working on developer tools, then Jane Street is kind of an amazing place. Apply here! There's no special posting, so just apply for the Software Engineering role, and express your interests in dev-tools in a note. janestreet.com/apply

TypeScript excitement 😉 The infamous Dimitri is cooking up a slick type analysis tool called TypeSlayer 🔥 "If you have a large enough project, there are performance problems where you can shave 100 seconds off CI by making a 5 line change. The problem is knowing out where to make that change."

now in early-access/alpha/beta/gamma/whatever-you-wanna-call-it. here's a walkthrough: youtu.be/IP6EZXzXBzY

⚔️introducing TypeSlayer⚔️ A #typescript type performance benchmarking and analysis tool. A summation of everything learned from the benchmarking required to make the Doom project happen. It's got MCP support, Perfetto, Speedscope, Treemap, duplicate package detection, and more.

It’s amazing how quickly the Go version of TypeScript was created. The key “trick” of the TS team was to port, not to rewrite: 2ality.com/2025/03/type...

It’s good! My main task right now at Vanta (when not wrangling organizational growth stuff) is migrating all of our packages to it, even the ones doing crazy shenanigans that tsgo catches and tsc incorrectly let pass. (There are only a handful in our millions of lines of code.) I repeat: it’s good!

TypeScript excitement 😉 News on the Go-based TS 7.0 🎉 🔷 Checker is very compatible with TS 5.9 🔷 Language Server maturity leapt forward 🔷 JS downlevel is limited: ES2021 now, ES2015 in future 🔷 JS checking gets stricter 🔷 No API access yet

I'm sure many of you have already been trying out the native preview, but if you haven't, now is the best time to start!

A status update on the TypeScript rewrite TL;DR - if you haven't tried it already, you should!

We've got some updates on TypeScript 7! The new native port - can type-check any project - supports --build and --incremental - has rich editor features implemented - is still 10x faster and is ready for you to try today! devblogs.microsoft.com/typescript/p...

who are all you people

FWIW we rolled out opt-in usage of the @typescriptlang.org native preview for in-editor workflows a few weeks ago at Vanta and the response has been extremely and overwhelmingly positive, the gaps in LSP support notwithstanding. I’m working on our blockers to just using it for all type checking.

My #BazelCon 2025 talk about how Canva used isolatedDeclarations to greatly improve typecheck performance youtu.be/26CoMExb6FE

Today on the pod, Daniel Rosenwasser & Jake Bailey reveal what's coming in TypeScript 6 & 7! Learn about ES2024 defaults, the new Go compiler, and smarter DOM typings. share.transistor.fm/s/ad05eae6 #typescript

Node excitement 😉 Congrats to @marcoippolito.dev on making it official: type-stripping in Node 25 is now declared to be stable 🎉 You can run: node index.ts The capabilities have not changed since Node 24. This is purely a maturity indicator.

Type stripping is now stable. Enjoy 🌞

I'm pleased that this year's GitHub survey acknowledges that untyped & typed JavaScript deserve to be counted as part of the same ecosystem. 🔶 New repos (last 12 months): JS 9.3M, Python 9.3M, TS 5.4M 🔶 Contributor delta (last 12 months): TS +1.1M, Python +0.9M, JS +0.4M 🔶 Contributor count chart

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...

We are still looking for feedback on tsgo, but it is worth calling out we expect some type-checking changes that you may need to adapt to. The native previews are easy to grab from npm, and are published nightly to try out! www.npmjs.com/package/@typ...

ECMAScript excitement 😉 @jason-williams.co.uk from TechAtBloomberg announces the release of Boa's Rust-based implementation of TC39 Stage 3 Temporal 🎉 Chrome estimates this will ship in Chromium 143 🎉🎉 Temporal is the shiny replacement for the broken JS Date API ✨

🚀 v1.104 of VS Code is here! Check out what's new: 🤖 Improved coding agent integration 📄 AGENTS.md file support for better context 🔍 New Auto mode (Preview) for smart model selection 🔑 Model flexibility via BYOK extension API …and more: aka.ms/VSCodeRelease Here are the highlights 🧵

@robpalmer.bsky.social makes a good point - `--strict`-by-default isn't the only thing to expect in TypeScript 6.0. We're trying to adopt better defaults and simplify for the future. Check out the current plans on our milestone: github.com/microsoft/Ty...

TypeScript excitement 😉 TS 6.0 is planning a bunch of breaking changes to tsconfig options to deprecate some and change the defaults for others. This will simplify configuration and ease the transition to the Go-based TS 7.0 👍 The latest pitch is to enable strict type-checking modes by default 🎉

Just filed an issue to turn `--strict` on by default in TypeScript. Maybe it's a little bit ambitious, but I'm excited for us to try this one. 😄 github.com/microsoft/Ty...

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

It's easy to miss a key feature of Node's TypeScript support that was released on Friday: it's zero config 💥 Meaning you don't need to put anything in package.json. Strictly speaking you don't even need a tsconfig to run the code. nodejs.org/en/blog/rele...

Node excitement 😉 Congrats to @marcoippolito.dev on today's landmark Node 22.18 release. It is the first LTS release to ship unflagged TypeScript support 🎉 This means Node can run *.ts files. It pairs well with TypeScript's "erasableSyntaxOnly" flag 👍 Many folk contributed 🙏

TypeScript excitement 😉 TS 5.9 is out 🎉 🔶 `import defer` by @nicr.dev 🔶 module: "node20" for require(ESM) 🔷 --init has modern defaults (no downleveling) 🔷 Docs: Inline summaries for DOM APIs 🔷 IDE: Expandable hovers to drill into Quick Infos 🔷 Perf: Faster type instantiation & file existence

TypeScript 5.9 is now available! 📣 This release brings: ✅ An updated tsc --init ✅ Type-checking for the new 'import defer' ✅ Actual summaries in more DOM APIs ✅ Expandable quick info hovers (✨preview✨) and more! Read up more on our blog: devblogs.microsoft.com/typescript/a...

🚀 v1.102 of VS Code is here! Check out what’s new: - MCP is GA with GitHub policy support - GitHub Copilot Chat is open source - Use custom modes for tailored chat - Background task management with Copilot coding agent …and so much more: aka.ms/VSCodeRelease 🧶 Here are some of the highlights…

🔥 I have news! After a 1y hiatus, I’m once again leading this year’s #StateOfHTML survey, thanks to generous funding by Google. ❤️ 🙋🏽‍♀️ Is there is an HTML feature or Web API you're dying to see progress on? Suggest it and it could be included! [1/2] lea.verou.me/blog/2025/de...

TypeScript 5.9 Beta just went out! Try it in your project and let us know what you think: devblogs.microsoft.com/typescript/a...

Last month, we announced plans to open source the GitHub Copilot Chat extension. Today, we've reached that milestone. Let's build the future of software development together: aka.ms/oss-ai-editor

Slack now runs the new Go-powered @typescriptlang.org checker in CI. Using the tool saves us over 5 minutes per run, meaning faster merges and happier developers. Huge thanks to Anders, @jakebailey.dev, and everyone else on the project for the incredible performance gains.

TypeScript excitement 😉 Congrats to @searyanc.dev on landing big updates to the default tsconfig settings used by `tsc --init` 🎉 Defaults matter - and in TS 5.9 they embrace simplicity 💙 🔷 ESM (was CommonJS) 🔷 No down-leveling (was ES2016) 🔷 verbatimModuleSyntax: true github.com/microsoft/Ty...

You're telling me a duck typed this code?

Why do the subways in Paris have to make that awful horror-movie-style synth sound?

📝 Typed Linting with Project Service In typescript-eslint 8.0, we stabilized a parserOptions.projectService option that uses powerful, streamlined TypeScript APIs for typed linting. Let's talk about why that's simpler and often faster than what came before. typescript-eslint.io/blog/project...

This post was first drafted as a PR in December 2023. We've been wanting to talk about the new Project Service option for typed linting for *ages*. 🙌

And now for something completely different:

ECMAScript excitement 😉 Firefox 139 ships the TC39 Stage 3 Temporal proposal 🎉 It's about time. Congrats to those who worked on the implementation including Andre Bargull & Dan Minor 👍 developer.mozilla.org/en-US/docs/M...

Trying to collect some data: what package that you know/maintain have transitioned to shipping ESM-only/ESM-first after it's unblocked by the support of require(esm)? Any tips/experiences to share?

ECMAScript excitement 😉 Congrats to champion JS Choi on conditionally advancing TC39 proposal Array.fromAsync to Stage 4 at TC39 today 🎉 It's like Array.from & works with async iterators. It's like the npm pkg it-all. It eliminates needing an adhoc for-await-of loop 👍 github.com/tc39/proposa...

ECMAScript excitement 😉 Congrats to @chronicles.org on conditionally advancing Explicit Resource Management to Stage 4 at TC39 today 🎉 It introduces `using` declarations and the Symbol.dispose protocol to deterministically and ergonomically release resources 👍 github.com/tc39/proposa...

ITS HAPPENING Firefox 127 shipped today making it the first browser to support Temporal - the new API for working with Dates, times, timezones + durations

TypeScript excitement 😉 The "tsgo" native Go port is now available on npm as an early preview 🎉 🔷 Checker: Most projects will see error parity with v5.8 🔷 Now supports JS and JSX 🔷 LSP: Auto-completions work 🔷 Perf: 10x win persists 🔷 API: Sync access via a Node addon