Simple nodejs Webserver

gistfile1.txt

const http = require('http');
const fs = require('fs');
const path = require('path');

const server = http.createServer((req, res) => {
  let filePath = path.join(__dirname, 'public', req.url === '/' ? 'index.html' : req.url);

  const ext = path.extname(filePath);
  let contentType = 'text/html';
  switch (ext) {
    case '.css':
      contentType = 'text/css';
      break;
    case '.js':
      contentType = 'text/javascript';
      break;
    case '.json':
      contentType = 'application/json';
      break;
  }

  fs.readFile(filePath, (err, content) => {
    if (err) {
      if (err.code === 'ENOENT') {	// Page not found
        fs.readFile(path.join(__dirname, 'public', '404.html'), (err, content) => {
          res.writeHead(404, { 'Content-Type': 'text/html' });
          res.end(content, 'utf-8');
        });
      } else { 		// Some server error
        res.writeHead(500);
        res.end(`Server Error: ${err.code}`);
      }
    } else {		// Success
      res.writeHead(200, { 'Content-Type': contentType });
      res.end(content, 'utf-8');
    }
  });
});

const PORT = 3000;
server.listen(PORT, () => {
  console.log('Running http://localhost:${PORT}/');
});