Node server which always 500s (with CORS support!)

package.json

{
  "name": "thefamous500",
  "version": "1.0.0",
  "main": "index.js",
  "license": "MIT",
  "dependencies": {
    "express": "^4.15.2"
  },
  "scripts": {
    "start": "node server.js"
  }
}

server.js

const server = require('express')();

// Log requests
server.use((req, res, next) => {
  console.log(req.method, req.url);
  next();
});

// CORS
server.use((req, res, next) => {
  // Echo back request configuration in "allowed" headers
  if(req.headers.origin) res.setHeader('access-control-allow-origin', req.headers.origin);
  if(req.headers['access-control-request-headers']) res.setHeader('access-control-allow-headers', req.headers['access-control-request-headers']);
  if(req.headers['access-control-request-method']) res.setHeader('access-control-allow-methods', req.headers['access-control-request-method']);

  // Tell browser not to cache preflight responses
  res.setHeader('access-control-max-age', 0);

  // Allow credentials
  res.setHeader('Access-Control-Allow-Credentials', 'true');

  if(req.method === 'OPTIONS') res.end();
  else next();
});

// Always serve 500s
const STATUS = process.env.STATUS || 500;
server.use((req, res) => {
  res.sendStatus(STATUS);
});

const PORT = process.env.PORT || 3000;
server.listen(PORT, () => {
  console.log(`Server listening on ::${PORT}; will respond to requests with status ${STATUS}`);
});