Interface definition for deno serve default export

[dojyorin]

Is there a interface definition for default export object?
I'm currently using workaround like this, but is there a better way?

export default <{fetch: Deno.ServeHandler}>{
    fetch(request){
        return new Response("Hello!");
    }
};

For example like this...

// lib.deno.ns.d.ts
export interface ServeDefaultExport {
    fetch: Deno.ServeHandler;
}

// my project
export default <Deno.ServeDefaultExport>{
    fetch(request){
        return new Response("Hello!");
    }
};