Fastify-guard NPM

fastify-guard

A simple user role and scope check plugin to protect endpoints for Fastify.

fastify-guard is designed to protect API endpoints by checking authenticated user roles and/or scopes if they met. guard is the registered Fastify decorator and can be used in anywhere.

Inspired by express-jwt-permissions.

Note: Fastify v4 support is shipped with v2.0.0.

Install

$ npm install fastify-guard

Usage

const fastify = require('fastify')()
const fastifyGuard = require('fastify-guard')

fastify.register(
  fastifyGuard,
  {
    errorHandler: (result, req, reply) => {
      return reply.send('you are not allowed to call this route')
    }
  }
)

// this route can only be called by users who has 'cto' and 'admin' roles
fastify.get(
  '/admin',
  { preHandler: [fastify.guard.role(['cto', 'admin'])] },
  (req, reply) => {
    // 'user' should already be defined in req object
    reply.send(req.user)
  }
)

// this route can only be called by users who has 'admin' or 'editor' role
fastify.get(
  '/',
  { preHandler: [fastify.guard.role('admin', 'editor')] },
  (req, reply) => {
    // 'user' should already be defined in req object
    reply.send(req.user)
  }
)

/*
http://localhost:3000 -> will print out below result if the authenticated user does not have 'admin' role

you are not allowed to call this route
*/

fastify.get(
  '/has-role',
  (req, reply) => {
    // 'user' should already be defined in req object
    reply.send(
      fastify.guard.hasRole(req, 'admin') // will return a boolean value
    )
  }
)

fastify.get(
  '/has-scope',
  (req, reply) => {
    // 'user' should already be defined in req object
    reply.send(
      fastify.guard.hasScope(req, 'profile') // will return a boolean value
    )
  }
)

fastify.listen(3000, () => {
  console.log('Fastify server is running on port: 3000')
})

/*
http://localhost:3000 -> will print out below result if the authenticated user does not have 'admin' role

you are not allowed to call this route
*/

Options

Name	Type	Default	Description
requestProperty	string	`user`	The authenticated user property name that fastify-guard will search in request object
roleProperty	string	`role`	The role property name that fastify-guard will search in authenticated user object
scopeProperty	string	`scope`	The scope property name that fastify-guard will search in authenticated user object
errorHandler	function	undefined	Custom error handler to manipulate the response that will be returned. As fallback, default HTTP error messages will be returned.

API

`guard.role(role)`

Returns a function which checks if the authenticated user has the given role(s). Multiple roles can be sent as separated parameters or in an array. If the given role(s) was not assigned to the authenticated user, the function will throw an HTTP Error (if no errorHandler provided in options otherwise the errorHandler will be invoked). The function supposed to be used in preHandler hook.

`guard.hasRole(request, role)`

Returns a boolean value which indicates the authenticated user has the given role.

request is the Fastify request object

role is role name

`guard.scope(scope)`

Returns a function which checks if the authenticated user has the given scope(s). Multiple scopes can be sent as separated parameters or in an array. If the given scope(s) was not assigned to the authenticated user, the function will throw an HTTP Error (if no errorHandler provided in options otherwise the errorHandler will be invoked). The function supposed to be used in preHandler hook.