mapAsync.ts

mapAsync.ts

const mapAsync = <T, R>(arr: T[], fn: (x: T) => Promise<R>) =>
  Promise.all(arr.map(fn));

(async () => {
  console.log("START MAP");
  const mapped = await mapAsync([1, 2, 3, 4], async (n) => {
    const x = await fakeAPI(n * 1000, n);
    return x * 10;
  });
  useResult(mapped);
  console.log("END MAP");
})();