# Error Middleware for Express ![build status](https://img.shields.io/circleci/project/github/gabrielsiedler/error-middleware.svg 'Build status') [![Coverage Status](https://coveralls.io/repos/github/gabrielsiedler/error-middleware/badge.svg?branch=master)](https://coveralls.io/github/gabrielsiedler/error-middleware?branch=master) This package handles errors on the express code and returns it with a fixed pattern, without leaks. It works with syncronous and asyncronous route functions. ## Installation `npm install error-middleware`
or
`yarn add error-middleware` --- ## Error Types Currently the middleware has exposed the following error types: - `BadRequestError` - `ForbiddenError` - `NotFoundError` - `UnauthorizedError` - `Validation Error` But you can also use - `CustomError` ## Error response format The consumer will receive a JSON object with `code`, `type` and `error` as folows: ``` { code: , type: , error: } ``` ## Example of expected responses

Code	Response
`throw new BadRequestError('User "id" is malformed.')`	`{ "code": 400, "type": "BadRequest", "error": "User 'id' is malformed." }`
`throw new ValidationError({ name: 'Name is too short.', email: 'Invalid email.' })`	`{ "code": 400, "type": "Validation", "error": { "name": "Name is too short.", "email": "Invalid email." } }`
`throw new CustomError( 'Not acceptable headers', 406, 'NotAcceptable' )`	`{ "code": 406, "type": "NotAcceptable", "error": "Not acceptable headers" }`
throw new Error(`Invalid user ${userId}`)	`{ "code": 500, "type": "InternalError", "error": "An internal error occurred." }`

## How to use - src/**index.js**
_Where you declare all your high level routes. The middleware should be last to be able to catch all errors._ ```js import errorMiddleware from 'error-middleware' import routes from './routes' router.use(routes) router.use(errorMiddleware) ``` - src/**routes.js** ```js import { BadRequestError, ValidationError, NotFoundError } from 'error-middleware/errors' router.put('/user/:id', (req, res) => { const { id } = req.params const { name, email } = req.body const idRegex = /^\d{4}$/ if (!idRegex.test(id)) { throw new BadRequestError(`User 'id' is malformed.`) } if (!validate(name, email)) { throw new ValidationError({ name: 'Name should be at least 4 characters long', email: 'Invalid email', }) } // your update logic goes here // { ... } res.sendStatus(200) }) router.get('/error', (req, res) => { // an endpoint that simulates a pure error being thrown. It will be translated to InternalError and all its content will not be leaked. throw new Error('Internal error that should not be leaked.') }) // If no matches found, return 404 router.use((req, res) => { throw new NotFoundError() }) ``` --- Check [examples](./examples/simple-server) for more

error-middleware

Downloads in past1 Month3 Months6 Months1 Year2 Years5 YearsAll time

Stats

Sick of boring JavaScript newsletters?

Downloads in past