This function finds the validation errors in this request and wraps them in an object with handy functions Now in user controller /controllers/user.js const User = require('./models/user')Įxports.createUser = (req, res, next) => If you are wondering what is validationResult(req)? Router.post('/', userController.createUser) Let's take a look at a basic user route without any validation module to create a user: /route/user.js /** The module implements five important API’s: The definition on Github says: express-validator is a set of express.js middlewares that wraps validator.js validator and sanitizer functions. In this tutorial, you’ll learn how to validate input in an Express.js app using an open source and popular module called express-validator.

you want to avoid using if ( ) or if ( ) in your main controller function where you define business logic.

you want to move fast while maintaining the quality of code or.

Writing your own middleware function can be cumbersome if If you have been building web applications using an Express framework or any other Node.js framework, validation plays a crucial role in any web app which requires you to validate the request body param query.

A user can turn off client-side JavaScript validation and manipulate the data.

More prone to Man in middle attacks, and the server should never trust the client-side.Your client side validation is not enough and it may be subverted.This tutorial requires prior knowledge of using the expressjs framework Why do we need server-side validation?

Expressvalidator