forEachAsync.ts

forEachAsync.ts

const forEachAsync = <T>(arr: T[], fn: (x: T) => any): Promise<any> =>
  arr.reduce(
    (promise: Promise<void>, value: T) => promise.then(() => fn(value)),
    Promise.resolve()
  );

(async () => {
  console.log("START FOREACH VIA REDUCE");
  await forEachAsync([1, 2, 3, 4], async (n) => {
    const x = await fakeAPI(n * 1000, n);
    useResult(x);
  });
  console.log("END FOREACH VIA REDUCE");
})();