express middleware

index.js

const express = require('express');
const bodyParser = require('body-parser');
const Validator = require('validatorjs');

const app = express();

// Middleware
const memberInputValidationGuard = function (req, res, next) {
  const data = {
    name: req.body.name,
    email: req.body.email,
  };

  const rules = {
    name: 'required|min:3',
    email: 'required|email',
  };
  
  const validation = new Validator(data, rules);
  
  if (validation.fails()) {
    return res.status(422).json({
      errors: {
        name: validation.errors.first('name'),
        email: validation.errors.first('email'),
      },
    });
  }
  
  // if validation pass, store data in request object
  req.data = data;
  
  return next();
};

app.use(bodyParser.json());

const members = [];

app.get('/members', function (req, res) {
  res.status(200).json({ members });
});

app.post(
  '/members',
  // use middleware 
  // see: https://expressjs.com/en/guide/writing-middleware.html
  // see: https://expressjs.com/en/guide/using-middleware.html
  memberInputValidationGuard,
  
  function (req, res) {
    // access data from req object
    // attached from previous middleware
    const data = req.data;
    
    members.push(data);
    
    res.status(201).json({
       message: 'User has been created',
    });
  }
);

const port = 8080;
app.listen(port, () => console.log('listening on port', port);

req.data = data;

ka kode yg ini utk perbarui request ka? klo dalam case challenge yg ini, tdk apa dihapus kan ka?