Convert to async/await doesn't support .finally() method

[DanielRosenwasser]

declare function delay(n: number): Promise<void>;

async function foo() {
    delay().then(x => delay(400)).then(x => delay(400)).finally(x => console.log(x));
}

[rjamesnw]

finally does not exist in any library except es2028.promise (the lib.es2018.promise.d.ts file). My guess is you could just copy it from there for now, or change your lib to es2018.

https://github.com/Microsoft/TypeScript/blob/master/lib/lib.es2018.promise.d.ts