Javascript AWS S3.upload gives a promise?

Question

The AWS instructions on S3 uploading (https://docs.aws.amazon.com/AWSJavaScriptSDK/latest/AWS/S3/ManagedUpload.html) would suggest that the following should work.

var managed = s3.upload(params, function(err, data) {
    if (err) {
        throw err;
    }
    console.log(`File uploaded successfully. ${data.Location}`);
});
p = managed.promise();
console.log(p);

s3.upload returns a ManagedUpload object, and this seems to be working. Supposedly the object has a promise() method that returns a promise that could be used with the .then programming style. However, when I actually try I'm getting

Uncaught TypeError TypeError: managed.promise is not a function

Is this documentation out of date? Is there a better one somewhere?

Answer 1

From the docs in upload() just enter the parameters, then() method should be called on the promise object to handle a result (resolve) or an error (reject).

var upload = s3.upload({Bucket: 'bucket', Key: 'key', Body: stream});
var promise = upload.promise();
promise.then(function(data) { ... }, function(err) { ... });