protect node.js app

protect-nodejs-app.js

// https://blog.logrocket.com/how-to-protect-your-node-js-applications-from-malicious-dependencies-5f2e60ea08f9

const fs = require('fs')
const path = require('path')
const wrap = (module, name, wrapper) => {
  const original = module[name]
  module[name] = wrapper(original)
}
wrap(fs, 'readFileSync', (readFileSync) => (...args) => {
  const [filepath] = args
  const fullpath = path.resolve(filepath)
  if (fullpath.startsWith('/system/')) {
    throw new Error('You do not have permissions to access this file')
  }
  return readFileSync(...args)
})
// Prevent further changes
Object.freeze(fs)