simple nodejs server for cpu, i/o benchmarking

server.js

#!/usr/bin/env node

// to run: `node server.js` or `./server.js`

var crypto = require("crypto"),
    fs = require('fs'),
    http = require("http");

function fibonacci (n) {
   if (n < 2) {
     return 1;
   } else {
     return fibonacci(n-2) + fibonacci(n-1);
   }
};

var server = http.createServer(function(req, res) {
  if (req.url == "/cpu") {
    res.writeHead(200, {"Content-Type": "text/plain"});
    res.write(String(fibonacci(30)));
    res.end();
  } else if (req.url == "/io") {
    res.writeHead(200, {"Content-Type": "text/plain"});
    fs.writeFile("./.tmp", crypto.randomBytes(1048576).toString('hex'), function (err) {
      if (err) {
        return console.log(err);
      } else {
        fs.readFile("./.tmp", 'utf8', function (err, data) {
          if (err) {
            return console.log(err);
          } else {
            res.writeHead(200);
            res.write(data)
            res.end();
          }
        });
      }
    });
  } else {
    res.writeHead(200);
    res.end();
  }
});

server.listen(8000);