Koa-Joi-Request-Validate

A small module to provide Joi validation middleware within a Koa server

This package support Joi verison from 16.1.8 and above

Need package support lower version of Joi below 16.1.8 use koa-joi-validate

Calling the module allows you to easily generate Koa middleware to validate incoming requests using Joi.

Install

npm install koa-joi-request-validate

Import

const validate = require('koa-joi-request-validate')

or

import validate from 'koa-joi-request-validate'

Usage

To use the module, call validate with an object containing two parameters schema and options.

schema can be any possible Joi valid schema. options parameter is optional and it can have all possible valid joi options.

The following basic example will verify that any request to the server contains a properly formatted request headers, params, query and body.

const Koa = require('koa')
const joi = require('joi')
const validate = require('koa-joi-request-validate')

const app = new Koa()

app.use(validate({
  headers: {
    schema: Joi.object({
        "userId": joi.string().alphanum().length(32)
    }),
    // Only for headers by default allowUnknown: true
    // options object can take any valid options availble in Joi.
    options: { allowUnknown: true } 
    
  },
  query: {
    schema: Joi.object({
        page: joi.string().required(),
        limit: joi.string().required()
    }) 
  },
  params: {
    schema: Joi.object({
        id: joi.string().required(),
    }) 
  }
  body: {
    schema: Joi.object({
        fname: joi.string().required(),
        lname: joi.string().required(),
        age: Joi.number().required()
    }) 
  }
}))

app.use(async ctx => {
  ctx.body = 'Hello World';
});


app.listen(5000)

Note Valid keywords are headers, params, query, body.

Here is another basic example, mounting a validator on a specific route using koa-router.

const router = new Router()

const loginValidator = validate({
  body: {
    schema: Joi.object({
        username: Joi.string().required(),
        password: Joi.string().required()
    })
  }
})

router.post('/login', loginValidator, async ctx => {
  const { username, password } = ctx.body
  const response = await login(username, password)
  ctx.body = response
})

For more examples of the (very powerful) validation capabilities of Joi, view the official documentation - https://joi.dev/api/?v=17.6.0

If the validation fails, an HTTP 400 response will be returned to the client, along with a short human-readable error message explaining why the request was rejected. For Example

"username" is required