[TypeScript] Async type signature always returns any

[leononame]

Description

Async does not generate correct type signature.

Repro code

REPL

Expected and actual results

It should have some type signature like export const doAsync: Async<string> instead of any, and ideally should be awaitable as well from typescript without giving errors.

Related information

• Fable version: dotnet fable --version
• Operating system

[MangelMaxime]

and ideally should be awaitable as well from typescript without giving errors.

I am not sure if this will be possible because in Fable when you use async we generate a custom async type which have the same behaviour as in .NET.

If you want asynchronous code to be await-able from TypeScrip you should use promise (coming from Fable.Promise) because in this case you will have a real promise.

Regarding the we could indeed type it to:

Fable/src/fable-library-ts/Async.ts

Lines 12 to 13 in b93f248

	// Implemented just for type references
	export class Async<_T> { }