VAYDER

A library that allows you to validate inputs on express routes via middlewares. It leverages the power of Joi and Celebrate with an easy, fluent interface for the middlewares to make it effortless to build a robust validation layer on your express server.

API:

| method | description | input | | ------ | ----------- | ----- | | validateBody | will validate the body of the request against the provided Joi Schema | Joi Schema | | validateParams | will validate the URL parameters passed into the request against the provided Joi Schema | Joi Schema | | validateQuery | will validate the request query string against the provided Joi Schema | Joi Schema | | validateHeaders | will validate the request Headers against the provided Joi Schema | Joi schema |

How to Use

1) Create a JOI schema

// schema.js

const Joi = require('joi');

module.exports = Joi.object().keys({
  foo: Joi.string().required(),
  bar: Joi.number().min(10).max(20),
});

2) Add it to your Express route

// app.js

const express = require('express');
const vayder = require('vayder');

const blahSchema = require('./schema.js');
const app = express();


app.post('/blah',
  vayder.validateBody(blahSchema),
  (req, res) => { res.send('Hello World!');}
);

app.listen(3000, () => {
  console.log('Example app listening on port 3000!');
});

Handling Errors

As per Joi docs, any validation failure that is caught by Joi will be thown as an error with the .isJoi property attached to it. It is recommended to have an error handling middleware at the bottom of your app.js to handle this:

app.use('*', (err, req, res, next) => {
    if(err.isJoi) {
      // do stuff
    }

    return next(err);
});

Advanced

Multiple Validations

You can do multiple validations in a very clear and concise syntax:

app.get('/',
  vayder.validateHeaders(AuthenticationSchema),
  vayder.validateQuery(paginationSchema),
  vayder.validateParams(userIdSchema),
  someController.doStuff);

Organizing Schemas

A useful way to organize / manage the schema imports is by creating a directory tree called models/validations in your project.

webapp
├── app.js
├── controllers
├── datasource
├── middlewares
├── models
│   └── validations
│       ├── accessToken.js
│       ├── accountSignUp.js
│       ├── index.js
│       ├── credentials.js
│       └── pagination.js
│
├── routes.js
├── serializers
├── services
└── utilities

Then, in the models/validations/index.js file, you can manage a single entry point to all the validations:

// index.js

module.exports = {
  accessToken: require('./accessToken'),
  accountSignUp: require('./accountSignUp'),
  credentials: require('./credentials'),
  pagination: require('./pagination'),
}

This makes for a cleaner interface when validating routes:

// routes.js
const vayder = require('vayder');
const schemas = require('./models/validations');

app.get('/',
  vayder.validateHeaders(schemas.accessToken),
  vayder.validateQuery(schemas.pagination),
  someController.doStuff
);