How do I use it in typescript?

[Drincann]

Is there a type declaration?

[iarna]

I think, without testing, that it'd roughly be (I'm not too sure on the exporting of a type this way):

interface FuncValidate {
  (rawSchemas: string, args: any[])
}
export default FuncValidate

If you want to test that and PR it, I'd take it =)