S3 listObjects async generator

s3-list-object.ts

import S3, { ObjectList } from 'aws-sdk/clients/s3';
import { PromiseResult } from 'aws-sdk/lib/request';
import { AWSError } from 'aws-sdk/lib/error';

export async function* listObjects(
  s3: S3,
  Bucket: string,
  Prefix?: string | undefined,
  StartAfter?: string | undefined,
): AsyncGenerator<ObjectList> {
  let res: PromiseResult<S3.ListObjectsV2Output, AWSError>;
  while (
    (res = await s3.listObjectsV2({ Bucket, Prefix, StartAfter }).promise()) &&
    res.Contents &&
    res.Contents.length > 0
  ) {
    StartAfter = res.Contents[res.Contents.length - 1].Key!; // eslint-disable-line @typescript-eslint/no-non-null-assertion
    yield res.Contents;
  }
}