Read raw upload data as stream in express js

index.js

const express = require('express')
const app = express()

const HOST = 'localhost'
const PORT = 8000

function hello( req, res ) {
    const msg = `Use curl http://${HOST}:${PORT}/upload --upload-file <somefile>`
    res.send(msg)
    res.end()
}

function upload( req, res ) {
    let bytes = 0
    req.on('data', data => bytes += data.length  )
    req.on('end', () => res.end( `You uploaded ${bytes} bytes of data\n` ) )
}

app.get('/', hello )
app.put('/upload', upload )


let server = app.listen( PORT, HOST )

// Handle Expect: 100-Continue
server.on('checkContinue', function(req,res) {
   res.writeContinue()
   server.emit('request', req, res )
})