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.

How to Use

1) Install vayder

npm install --save vayder

2) 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),
});

3) 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!');
});

API:

method	description	inputs
validateBody	will validate the body of the request against the provided Joi Schema	Joi Schema, Joi Schema Options [optional]
validateParams	will validate the URL parameters passed into the request against the provided Joi Schema	Joi Schema, Joi Schema Options [optional]
validateQuery	will validate the request query string against the provided Joi Schema	Joi Schema, Joi Schema Options [optional]
validateHeaders	will validate the request Headers against the provided Joi Schema	Joi schema, Joi Schema Options [optional]

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);

Passing in Joi Options

Every method allows you to pass in an optional config of all the Joi options you want to run on the schema. For example:

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

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
);