No errors with express-validator isEmpty

Question

I am using express-validator 5.2.0 in a expressjs app. I implemented the validaiton on a form data. But it does not capture the errors and gives empty errors object. When validation runs it shows the "no error" when I submit the empty form. It should follow the error path and should display the error.

var express = require('express');
var router = express.Router();
const { check, validationResult } = require('express-validator/check');

router.post('/register', [
  check('firstName', 'First Name is required').isEmpty(),
  check('lastName', 'Last Name is required').isEmpty(),
  check('username', 'User Name is required').isEmpty(),
  check('password', 'Password is required').isEmpty()
], (req, res, next)=>{
  let errors = validationResult(req);
  if (!errors.isEmpty()) {
    console.log(errors.mapped());
    console.log("errors")
    return res.render('auth/register', { errors: errors.mapped() })
  }else{
    console.log('no errors')
    return res.render('auth/login');
  }

Answer 1

check('firstName', 'First Name is required').isEmpty() is enforcing firstName to be empty.
You will want to change that last part to .not().isEmpty(), so that you invert the isEmpty validator.

_{Might also be of your interest: https://github.com/express-validator/express-validator/issues/476}