mapAsync

/**
 * @param {Array<any>} iterable
 * @param {Function} callbackFn
 *
 * @return {Promise}
 */
export default function mapAsync(iterable, callbackFn) {
  return Promise.all(
    iterable.map((item, index) => callbackFn(item, index, iterable))
  );
}

/**
 const asyncDouble = (x: number) =>
  new Promise((resolve) => {
    setTimeout(() => {
      resolve(x * 2);
    }, 10);
  });

const doubled = await mapAsync([1, 2], asyncDouble);
console.log(doubled); // [2, 4]
 */