Async iterators utils

asyncEach.ts

export async function asyncEach<T>(
  array: { map(callback: (value: T) => any): Promise<any>[] },
  iteratee: (value: T) => Promise<any>,
) {
  return Promise.all(array.map(iteratee));
}

export async function asyncEachSeries<T>(
  array: {
    reduce(callback: (prev: any, value: T, index: number) => any, initialValue: any): any;
  },
  iteratee: (value: T, index: number) => Promise<any>,
): Promise<void> {
  return array.reduce(
    (promise, value, index) => promise.then(() => iteratee(value, index)),
    Promise.resolve(),
  );
}