File uploading with Express 4.0: req.files undefined

Question

I'm attempting to get a simple file upload mechanism working with Express 4.0 but I keep getting undefined for req.files in the app.post body. Here is the relevant code:

var bodyParser = require('body-parser');
var methodOverride = require('method-override');
//...
app.use(bodyParser({ uploadDir: path.join(__dirname, 'files'), keepExtensions: true })); 
app.use(methodOverride()); 
//...
app.post('/fileupload', function (req, res) {
  console.log(req.files); 
  res.send('ok'); 
}); 

.. and the accompanying Pug code:

form(name="uploader", action="/fileupload", method="post", enctype="multipart/form-data")
    input(type="file", name="file", id="file")
    input(type="submit", value="Upload")

Solution
Thanks to the response by mscdex below, I've switched to using busboy instead of bodyParser:

var fs = require('fs');
var busboy = require('connect-busboy');
//...
app.use(busboy()); 
//...
app.post('/fileupload', function(req, res) {
    var fstream;
    req.pipe(req.busboy);
    req.busboy.on('file', function (fieldname, file, filename) {
        console.log("Uploading: " + filename); 
        fstream = fs.createWriteStream(__dirname + '/files/' + filename);
        file.pipe(fstream);
        fstream.on('close', function () {
            res.redirect('back');
        });
    });
});

Answer 1

The body-parser module only handles JSON and urlencoded form submissions, not multipart (which would be the case if you're uploading files).

For multipart, you'd need to use something like connect-busboy or multer or connect-multiparty (multiparty/formidable is what was originally used in the express bodyParser middleware). Also FWIW, I'm working on an even higher level layer on top of busboy called reformed. It comes with an Express middleware and can also be used separately.