export async function asyncReduce<U, T = any>(
  arr: ReadonlyArray<T>,
  iter: (
    memo: U,
    value: T,
    index: number,
    arr: ReadonlyArray<T>
  ) => U | Promise<U>,
  startValue: U | Promise<U>
) {
  let endValue = await startValue
  for (let i = 0; i < arr.length; i++) {
    endValue = await iter(endValue, arr[i], i, arr)
  }
  return endValue
}