tsrs: a faster spell-checker for your app's code

A quieter kind of upgrade

A lot of the web apps you use, and maybe the one your business runs on, are written in a language called TypeScript. Behind it sits a strict proofreader that reads every line and flags mistakes before a customer ever sees them. It's wonderful. It can also be slow and hungry for memory on big projects.

Microsoft is rebuilding that proofreader for TypeScript 7. Now the oxc team has started something called tsrs: a copy of Microsoft's new version, translated function by function into a language called Rust. The aim is identical results, faster checking and much less memory.

Why it caught my eye

What I love is the promise they make. If tsrs gives a single different answer from Microsoft's version, a different warning, a different order, even different wording, they count it as their own bug. Same proofreader, just quicker on its feet. And it's a drop-in, so in theory your team swaps it in and changes nothing else.

People noticed. It landed on a list of GitHub projects whose popularity more than tripled in a week.

Words worth knowing

• TypeScript: a popular language for building websites and web apps.
• Type checker: the proofreader that catches mistakes in code before it runs.
• Language server: the helper that underlines errors in a developer's editor as they type.
• Drop-in replacement: a part you can swap in without rebuilding anything around it.

Something to ask

Next time you chat with your developers or agency, ask whether they use TypeScript and how long they wait for checks. If the answer comes with a sigh, tsrs is worth keeping an eye on. It's still a goal in progress, but a lovely one.