http-errors

What is http-errors?

The http-errors npm package is used to create HTTP error objects within Node.js applications. It provides a simple way to generate error objects that follow the HTTP response status codes and messages. This can be particularly useful when building web applications or APIs where you need to return specific error information to the client.

What are http-errors's main functionalities?

Creating HTTP error objects

This feature allows you to create error objects that correspond to HTTP response status codes. You can also provide a custom error message.

{"const createError = require('http-errors');\n\n// Create a 404 Not Found error\nconst notFoundError = createError(404);\n\n// Create a 500 Internal Server Error with a custom message\nconst internalServerError = createError(500, 'Something went wrong!');"}

Creating error objects with properties

This feature allows you to create error objects with additional properties, such as 'expose' to control whether the message should be sent to the client.

{"const createError = require('http-errors');\n\n// Create a 401 Unauthorized error with additional properties\nconst unauthorizedError = createError(401, 'Please login to view this page', { expose: false });"}

Checking if an object is an HTTP error

This feature provides a utility to check if a given object is an instance of an HTTP error.

{"const createError = require('http-errors');\n\n// Create an error object\nconst err = createError(404);\n\n// Check if 'err' is an HTTP error\nconst isError = createError.isHttpError(err); // true"}

Other packages similar to http-errors

boom

Boom is a set of utilities for returning HTTP errors. It is similar to http-errors but also includes a rich set of options for decorating the error object, such as automatic payload formatting according to the error type.

restify-errors

Restify-errors is designed to work with the Restify framework and provides a way to create and manage HTTP errors. It is similar to http-errors but is more tightly integrated with Restify's API.

README

http-errors

Create HTTP errors for Express, Koa, Connect, etc. with ease.

Install

This is a Node.js module available through the npm registry. Installation is done using the npm install command:

$ npm install http-errors

Example

var createError = require('http-errors')
var express = require('express')
var app = express()

app.use(function (req, res, next) {
  if (!req.user) return next(createError(401, 'Please login to view this page.'))
  next()
})

API

This is the current API, currently extracted from Koa and subject to change.

Error Properties

• expose - can be used to signal if message should be sent to the client, defaulting to false when status >= 500
• headers - can be an object of header names to values to be sent to the client, defaulting to undefined. When defined, the key names should all be lower-cased
• message - the traditional error message, which should be kept short and all single line
• status - the status code of the error, mirroring statusCode for general compatibility
• statusCode - the status code of the error, defaulting to 500

createError([status], [message], [properties])

Create a new error object with the given message msg. The error object inherits from createError.HttpError.

var err = createError(404, 'This video does not exist!')

• status: 500 - the status code as a number
• message - the message of the error, defaulting to node's text for that status code.
• properties - custom properties to attach to the object

createError([status], [error], [properties])

Extend the given error object with createError.HttpError properties. This will not alter the inheritance of the given error object, and the modified error object is the return value.

fs.readFile('foo.txt', function (err, buf) {
  if (err) {
    if (err.code === 'ENOENT') {
      var httpError = createError(404, err, { expose: false })
    } else {
      var httpError = createError(500, err)
    }
  }
})

• status - the status code as a number
• error - the error object to extend
• properties - custom properties to attach to the object

createError.isHttpError(val)

Determine if the provided val is an HttpError. This will return true if the error inherits from the HttpError constructor of this module or matches the "duck type" for an error this module creates. All outputs from the createError factory will return true for this function, including if an non-HttpError was passed into the factory.

new createError[code || name]([msg]))

Create a new error object with the given message msg. The error object inherits from createError.HttpError.

var err = new createError.NotFound()

• code - the status code as a number
• name - the name of the error as a "bumpy case", i.e. NotFound or InternalServerError.

List of all constructors

Status Code	Constructor Name
400	BadRequest
401	Unauthorized
402	PaymentRequired
403	Forbidden
404	NotFound
405	MethodNotAllowed
406	NotAcceptable
407	ProxyAuthenticationRequired
408	RequestTimeout
409	Conflict
410	Gone
411	LengthRequired
412	PreconditionFailed
413	PayloadTooLarge
414	URITooLong
415	UnsupportedMediaType
416	RangeNotSatisfiable
417	ExpectationFailed
418	ImATeapot
421	MisdirectedRequest
422	UnprocessableEntity
423	Locked
424	FailedDependency
425	TooEarly
426	UpgradeRequired
428	PreconditionRequired
429	TooManyRequests
431	RequestHeaderFieldsTooLarge
451	UnavailableForLegalReasons
500	InternalServerError
501	NotImplemented
502	BadGateway
503	ServiceUnavailable
504	GatewayTimeout
505	HTTPVersionNotSupported
506	VariantAlsoNegotiates
507	InsufficientStorage
508	LoopDetected
509	BandwidthLimitExceeded
510	NotExtended
511	NetworkAuthenticationRequired

License

MIT