createServer.js

if(stats.isFile()) {
    var mimeType = mimeTypes[path.extname(fileName).split(".").reverse()[0]];
    res.writeHead(200, {'Content-type': mimeType});

    var fileStream = fs.createReadStream(fileName);
    fileStream.pipe(res);
} else if (stats.isDirectory()) {
    res.writeHead(302, {
        'Location': 'index.html'
    });
    res.end();
} else {
    res.writeHead(500, {'Content-type': 'text/plain'});
    res.write('500 Internal Error\n');
}