[chaos_emergent]

Deepkit is a fantastic solution for this. It uses a compilation step to inject metadata about types into plain JS.

https://deepkit.io/

[jitl]

Deepkit looks really cool, but it’s so complex on the inside and leverages a forked/patched Typescript and requires full typecheck before emit.

What happens if the Deepkit guy retires? What if I want to run my code without waiting for 11 minutes of typechecking? What if there’s a bug somewhere in there?

There’s way too much risk for me to consider Deepkit for production.