Swagger Express Validator

swagger-express-validator is a lightweight middleware for request/response validation based on OpenAPI v2.0 (aka swagger) specification.

The main difference of this package to alternatives like swagger-tools is that this package is very configurable and only concentrates on validation against provided schema. You can choose the behavior of invalid validation like returning a 500 or just logging an error to your logger.

Requirements

• express ^4.0.0
• body-parser ^1.0.0

Features

• Configurable validation behavior
• Fastest available JSON schema validation based on ajv library
• Optional validations for either request parameters or response values
• Independent from express application structure. This is a simple drop-in middleware without additional alterations to your swagger definitions or application routing.
• Support for nullable field validation though x-nullable attribute

Installation

Start using this library with npm install swagger-express-validator --save

Sample use

To set up simple validation for your requests and responses:

const util = require('util');
const express = require('express');
const bodyParser = require('body-parser');
const validator = require('swagger-express-validator');
const schema = require('./api-schema.json');

const server = express();
server.use(bodyParser.json());

const opts = {
  schema,
  validateRequest: true,
  validateResponse: true,
  requestValidationFn: (req, data, errors) => {
    console.log(`failed request validation: ${req.method} ${req.originalUrl}\n ${util.inspect(errors)}`)
  },
  responseValidationFn: (req, data, errors) => {
    console.log(`failed response validation: ${req.method} ${req.originalUrl}\n ${util.inspect(errors)}`)
  },
};
server.use(validator(opts));

server.use('/status', (req, res) => {
  res.json({
    status: 'OK',
  })
});
server.use((err, req, res, next) => {
  res.status(500);
  res.json(err);
});

return server.listen(3000);

Debugging

To see debug output use DEBUG=swagger-express-validator as an environmental variable when starting your project, eg.: DEBUG=swagger-express-validator node server.js. To gain more insights on how this works see documentation of debug library

Contributors

• Nazar Gargol
• Isaac Stefanek
• James Gregory

Licence

MIT

Special thanks to @bgaluszka for initial inspiration :)