Multi-part forms usually break express as the expected body is not present.. This is also true for a JS app posting to Node if the JS app builds a FormData object:
The above npm package fixes this. It acts as a middleware to auto format incoming requests into the nice body and file format you are expecting. In your press middleware loader add the following:
import expressFormData from 'express-form-data'
// parse data with connect-multiparty
// clear all empty files (size == 0)
// change file objects to node stream.Readable
// union body and files