AsyncReturnType doesn't work

[UberMouse]

I'm not sure how AsyncReturnType is supposed to work. If I try it with a basic async function, that takes a string argument & returns it, I get a type error.

Type '(bar: string) => Promise' does not satisfy the constraint 'AsyncFunction'.
Types of parameters 'bar' and 'args' are incompatible.
Type 'unknown' is not assignable to type 'string'

I've set up a Codesandbox that demonstrates this. I'm not sure what Typescript version it's using, it's not listed in the dependencies, but I am getting it with TS v3.8.2 in my local project.

I'm not sure if there is a specific reason not to use any here, but replacing ...args: unknown[] with ...args: any[] in the AsyncFunction definition resolves the error.

[sindresorhus]

// @resynth1943

[resynth1943]

Ahhh. I know exactly what this is.