Upload file to google drive using javascript sdk

I searched lot and found nothing about how to send files. Even in google documentation there is nothing about sending file using Javascript sdk.

See here https://developers.google.com/drive/v3/web/manage-uploads

So right now I'm converting the nodeJs script to javascript. And they used fs to get the readstream. And I have no idea how to do that in javascript. Closet I can get to this...

var file = uploadButton.files[0]
var fileName = uploadButton.files[0].name

var fileMetadata = {
  'name': fileName
};

var media = {
  mimeType: 'image/jpeg',
  body: file
};

gapi.client.drive.files.create({
   resource: fileMetadata,
   media: media.result,
   fields: 'id'
}).execute();

via RobC