function uploadFileToS3(filePath, fileName) { let s3Stream = S3Stream(new AWS.S3()); let read = fs.createReadStream(filePath + fileName); let compress = zlib.createGzip(); let upload = s3Stream.upload({ Bucket: "static.smartystreets.com", Key: "sdk/" + version + "/" + fileName, StorageClass: "STANDARD", ContentType: "application/javascript", ContentEncoding: "gzip", }); upload.on("error", e => { throw new e }); upload.on("part", console.log); upload.on("uploaded", console.log); read .pipe(compress) .pipe(upload); }