allSettled

allSettled.ts

interface FulfilledPromise<T> {
  status: 'fulfilled';
  value: T;
}

interface RejectedPromise {
  status: 'rejected';
  reason: string;
}

function allSettled<T>(
  arr: Promise<T>[],
): Promise<(FulfilledPromise<T> | RejectedPromise)[]> {
  return Promise.all(
    arr.map(p =>
      p.then(
        (v: T) => ({ status: 'fulfilled', value: v }),
        (e: Error) => ({ status: 'rejected', reason: e.message }),
      ),
    ),
  );
}