server.js

const express = require('express'),
  app = express(),
  cors = require('cors'),
  bodyParser = require('body-parser'),
  delay = 100;

const fs = require('fs');

// read your a file called data
app.get('/data', function (req, res) {
  let data = fs.readFileSync('./data.txt');
  res.status(200)
  res.send(data)
})

// post your data, write to a file caled data
app.post('/data', function (req, res) {
  fs.writeFileSync('./data.txt', req.body.data, 'utf-8')
})

app.listen(4200, function () {
  console.log('design token running on 4200!');
});