Simple File Uploads with Node.js & Express
A quick example of how to get a file upload up & running using Express with Node.js when you need to handle some file processing on the server.
Missing name attribute
Inputs submitted without a name attribute will spit out a rather unhelpful trace. Double check name is set on the input element itself.
req.files undefined or empty
As of Express 4.x, the middleware for processing multipart/form-data was removed from the bodyParser middleware, leaving only the application/x-www-form-urlencoded and application/json body data parsers.
If you can skip back to Express 3.x then hey presto, otherwise there are plenty of custom parsers for handling multipart such as multer or busboy