validate-express

A thin middleware for express applications that handles validation.

The code is pretty minimal and only depends on the joi package for the schema definition and validation logic.

After successful validation, the request object is modified to contain the validated/updated values.

Installing

npm install --save validate-express

Example

var express    = require('express'),
    bodyParser = require('body-parser'),
    validate   = require('validate-express'),
    joi        = require('joi');

var app = express();
app.use(bodyParser.urlencoded({extended: false}));
app.use(bodyParser.json());

var validation = {
    login : {
        post: {
            body: {
                identification: joi.string().required(),
                password      : joi.string().required()
            }
        }
    },
    search: {
        post: {
            body: {
                q    : joi.string().required(),
                to   : joi.date().default(function () {
                    return new Date();
                }, 'to date'),
                limit: joi.number().max(20).min(10).default(10)
            },
            before: {
                // demonstrates providing a custom transform that is called prior to validation
                to: function (value) {
                    return value === 'now' ? new Date() : value;
                }
            },
            after : {
                // demonstrates providing a custom transform that is called after successful validation
                q: function (value) {
                    return value.toUpperCase();
                }
            }
        }
    },
    me    : {
        get: {
            headers: {
                apikey      : joi.string().required(),
                'user-agent': joi.string().required().regex(/chrome/)
            }
        }
    }
};

app.post('/login', validate(validation.login.post), function (req, res) {
    // ...
});

app.post('/search', validate(validation.search.post), function (req, res) {
    // ...
    // NOTE - req.body will contain the validated/udpated values
    // e.g. if the user did not provide 'to' or 'limit' fields in the request, they now exist
    // ALSO, if the user specified to==='now', then a new Date() will be created via the transform
});

app.get('/me', validate(validation.me.get), function (req, res) {
    // ...
});

// NOTE: don't forget to provide error middleware
app.use(function (err, req, res, next) {
    if (err.name === 'ValidationError') {
        res.status(err.status).json(err);
    }
});

License

validate-express is released under the MIT license.