http server that always returns 500 status

500-server.js

'use strict'

const http = require('http')

const server = http.createServer( (req, res) => {
  res.writeHead(500, {'Content-Type': 'text/plain'})
  res.end('500')
})

const PORT = process.env.PORT || "3000"
server.listen(PORT, function () {
  console.log("server listening on http://localhost:" + PORT)
})