@sloang/joi-middleware

A validation middleware for expressjs using Joi.

Remove validation from your controllers and put them into your middleware.

Usage

const express = require('express')
const app = express()
const joi = require('@hapi/joi')
const joiMiddleware = require('@sloang/joi-middleware')
const joiValidationObject = joi.object({
    title: joi.string().min(5).max(40).required()
})

app.post('/', joiMiddleware(joiValidationObject), (req, res, next) => {
    res.status(200).send('It Works')
})

app.use((err, req, res, next) => {
    if (err.name == 'ValidationError') {
        res.status(400).send('Validation Error')
    }
})

outputs

On valid validation

It Works

On failed validation

Validation Error

API

let joiMiddleware = require('@sloang/joi-middleware')

joiMiddlware(validationObject)

When joiMiddleware is called only with the Joi validationObject it defaults to validating req.body you can validate other objects by using joiMiddleware(validationObject, object). If validation fails next is called with the validation error as its argument. Otherwise next is called with no argument

joiMiddleware(validationObject, object)

When using this method you are providing the middleware both the Joi validation object and the object to be validated. If validation fails next is called with the validation error as its argument. Otherwise next is called with no argument. This method can be useful when trying to validate other request object keys. For example

const router = require('express').Router()
let joiMiddleware = require('@sloang/joi-middleware')

router.post('/test', 
(req, res, next) => 
    joiMiddleware(userValidator, req.user)(req, res, next))

Important Note

Joi is technically not specifically required for this middleware to work. Any validation package that has a .validate method that returns an object with an error key ({error}) when the object is invalid should in theory work for this middleware, however, Joi is used in test and should always be functional with this package.

Install

With npm installed, run

$ npm install @sloang/joi-middleware @hapi/joi

See Also

• @hapi/joi
• express
• How express middleware works

License

MIT