joke-server.js

const { createServer } = require('http');
const fs = require('fs');
const path = require('path');

const jokesDir = path.join(__dirname, 'jokes');

const jokes = fs.readdirSync(jokesDir).map(jokeFile => {
  const jokeData = fs.readFileSync(path.join(jokesDir, jokeFile));
  return JSON.parse(jokeData);
});

let jokeIndex = -1

createServer((req, res) => {
  if (req.url === '/joke-me') {
    // get a request ID so we can see in the console start/end
    const id = Math.random().toString(32).substr(2,5)

    // cycle through the jokes
    jokeIndex = (jokeIndex + 1) % jokes.length
    const joke = jokes[jokeIndex];

    console.log(id, 'started');

    // Fake some latency
    setTimeout(() => {
      res.writeHead(200, { 'Content-Type': 'application/json' });
      res.write(JSON.stringify(joke, null, 2));
      res.end();
      console.log(id, 'completed');
    }, Math.random() * 2000);
  } else {
    res.writeHead(404, { "Content-Type": "text/plain" })
    res.write("404 Not Found")
    res.end()
  }
}).listen(5000, () => {
  console.log('Get a joke! http://localhost:5000/joke-me');
});