If you opened this article, you probably already agree with me: sometimes TypeScript compiles painfully slowly.
The same thing happened to @_chenglou — an amazing dev who inspires me (he worked on React, Messenger, ReasonML and ReScript, and currently Midjourney, Pretext).
He's also a user of Sury — the fastest schema validation library, which I maintain — and the author of this issue: "Large TS types cause type inference slowdown".
That's... not nice. But I knew ArkType exists, and that people have built wild things in TS's type system (Doom included). So the slowness was clearly solvable, not fundamental. Here's the recipe I used. You can apply it to your own library.
Before we begin, here are the results. These are type-instantiation counts, measured with @ark/attest:
