Typescript types for gnome-shell is a thing:
which is then used to generate the types in:
https://github.com/gjsify/types
If ts-for-git becomes available, it could (as a hook, maybe ?) generate the types for the gir libraries in debian.
it's used by at least one gnome-shell extension (copyous, which I'm trying to package).
(cross-posting to gnome-gtk and debian-js, since it concerns both).
Jérémy