Recursive S3 folder traversal in TS

traverse.ts

const getKeysFromPrefix = async (s3: S3Client, prefix: string, bucket: string) => {
   const keys = await s3.send(new ListObjectsCommand({
    Bucket: bucket,
    Delimiter: '/',
    Prefix: prefix
  })).then(response => {
    if(response.CommonPrefixes) {
      // Recursive call to go into folders
      const promises = []
      response.CommonPrefixes.forEach(p => promises.push(getKeysFromPrefix(s3, p.Prefix, bucket)))
      return Promise.all(promises);
    } else {
      // Collect the keys from contents
      const keys = []
      response.Contents.forEach(c => keys.push({
        key: c.Key,
        lastModified: c.LastModified,
        etag: c.ETag,
        size: c.Size,
        storageClass: c.StorageClass,
        owner: c.Owner
      }))
      return keys;
    }
  })

  // Flatten the response arrays of keys
  return keys.flat()
}