visionmedia/superagent — pull request #371 by TooTallNate (2014-04-25 22:55:11+00:00)
Title: node: ability to .attach() a `fs.ReadStream` instance

This allows us to do, i.e.:

``` js
request.post('/upload')
.attach('file', fs.createReadStream('foo.txt'))
.end(fn);
```

Eventually it would be better to add support for arbitrary `stream.Readable` instances, but this is good enough for now.