express-purity

Express purity is middleware for your express application to enforce constraints on the data which flows through it.

Express purity is installable from npm:

npm install express-purity --save

Usage Guide

Create Schemas to validate your data.

import { Schema } from 'express-purity';
 
const schema = Schema({
  name: { $type: String, $required: true },
  age: { $type: Number },
  email: { $type: String, $required: true, $transform: v => v.toLowerCase() }
});

Once you have a schmea, you can use it in your express app:

app.post('/users/createuser', schema, createUserRoute);

By default the schema will validate against request.body.

// your app receives data
// -> request.body = { name: 'jerry', email: '[e-mail]' }
 
// in createUserRoute
function createUserRoute (req, res) {
  assert.equal(req.body.name, 'jerry');
  assert.equal(req.body.email, '[e-mail]');
  assert(!('age' in req.body));
}

Errors will be handed to next(). Pick them up in your error handler.

import { ValidationError } from 'express-purity';
 
app.use((err, req, res, next) => {
  if (err instanceof VaidationError) {
    return res.status(460).end(err.message);
  } else {
    res.sendStatus(404);
  }
});

API Reference

For the full api on creating Schemas please read the docs for purity.

Schema(definition [, options])

express-purity adds 2 additional options for schemas:

options.target {String}

The target property on request to validate. Defaults to 'body'.

options.modify {Boolean}

Whether or not to modify the request object's target property. Defaults to true. (Note it is necessary to set this to false when options.target is a read-only property).

Bugs and Features

Please log issues and feature requests on the github issue tracker.