/*!
* http-errors
* Copyright(c) 2014 Jonathan Ong
* Copyright(c) 2016 Douglas Christopher Wilson
* MIT Licensed
*/
'use strict'
/**
* Module dependencies.
* @private
*/
var deprecate = require('depd')('http-errors')
var setPrototypeOf = require('setprototypeof')
var statuses = require('statuses')
var inherits = require('inherits')
var toIdentifier = require('toidentifier')
/**
* Module exports.
* @public
*/
module.exports = createError
module.exports.HttpError = createHttpErrorConstructor()
module.exports.isHttpError = createIsHttpErrorFunction(module.exports.HttpError)
// Populate exports for all constructors
populateConstructorExports(module.exports, statuses.codes, module.exports.HttpError)
/**
* Get the code class of a status code.
* @private
*/
function codeClass (status) {
return Number(String(status).charAt(0) + '00')
}
/**
* Create a new HTTP Error.
*
* @returns {Error}
* @public
*/
function createError () {
// so much arity going on ~_~
var err
var msg
var status = 500
var props = {}
for (var i = 0; i < arguments.length; i++) {
var arg = arguments[i]
var type = typeof arg
if (type === 'object' && arg instanceof Error) {
err = arg
status = err.status || err.statusCode || status
} else if (type === 'number' && i === 0) {
status = arg
} else if (type === 'string') {
msg = arg
} else if (type === 'object') {
props = arg
} else {
throw new TypeError('argument #' + (i + 1) + ' unsupported type ' + type)
}
}
if (typeof status === 'number' && (status < 400 || status >= 600)) {
deprecate('non-error status code; use only 4xx or 5xx status codes')
}
if (typeof status !== 'number' ||
(!statuses.message[status] && (status < 400 || status >= 600))) {
status = 500
}
// constructor
var HttpError = createError[status] || createError[codeClass(status)]
if (!err) {
// create error
err = HttpError
? new HttpError(msg)
: new Error(msg || statuses.message[status])
Error.captureStackTrace(err, createError)
}
if (!HttpError || !(err instanceof HttpError) || err.status !== status) {
// add properties to generic error
err.expose = status < 500
err.status = err.statusCode = status
}
for (var key in props) {
if (key !== 'status' && key !== 'statusCode') {
err[key] = props[key]
}
}
return err
}
/**
* Create HTTP error abstract base class.
* @private
*/
function createHttpErrorConstructor () {
function HttpError () {
throw new TypeError('cannot construct abstract class')
}
inherits(HttpError, Error)
return HttpError
}
/**
* Create a constructor for a client error.
* @private
*/
function createClientErrorConstructor (HttpError, name, code) {
var className = toClassName(name)
function ClientError (message) {
// create the error object
var msg = message != null ? message : statuses.message[code]
var err = new Error(msg)
// capture a stack trace to the construction point
Error.captureStackTrace(err, ClientError)
// adjust the [[Prototype]]
setPrototypeOf(err, ClientError.prototype)
// redefine the error message
Object.defineProperty(err, 'message', {
enumerable: true,
configurable: true,
value: msg,
writable: true
})
// redefine the error name
Object.defineProperty(err, 'name', {
enumerable: false,
configurable: true,
value: className,
writable: true
})
return err
}
inherits(ClientError, HttpError)
nameFunc(ClientError, className)
ClientError.prototype.status = code
ClientError.prototype.statusCode = code
ClientError.prototype.expose = true
return ClientError
}
/**
* Create function to test is a value is a HttpError.
* @private
*/
function createIsHttpErrorFunction (HttpError) {
return function isHttpError (val) {
if (!val || typeof val !== 'object') {
return false
}
if (val instanceof HttpError) {
return true
}
return val instanceof Error &&
typeof val.expose === 'boolean' &&
typeof val.statusCode === 'number' && val.status === val.statusCode
}
}
/**
* Create a constructor for a server error.
* @private
*/
function createServerErrorConstructor (HttpError, name, code) {
var className = toClassName(name)
function ServerError (message) {
// create the error object
var msg = message != null ? message : statuses.message[code]
var err = new Error(msg)
// capture a stack trace to the construction point
Error.captureStackTrace(err, ServerError)
// adjust the [[Prototype]]
setPrototypeOf(err, ServerError.prototype)
// redefine the error message
Object.defineProperty(err, 'message', {
enumerable: true,
configurable: true,
value: msg,
writable: true
})
// redefine the error name
Object.defineProperty(err, 'name', {
enumerable: false,
configurable: true,
value: className,
writable: true
})
return err
}
inherits(ServerError, HttpError)
nameFunc(ServerError, className)
ServerError.prototype.status = code
ServerError.prototype.statusCode = code
ServerError.prototype.expose = false
return ServerError
}
/**
* Set the name of a function, if possible.
* @private
*/
function nameFunc (func, name) {
var desc = Object.getOwnPropertyDescriptor(func, 'name')
if (desc && desc.configurable) {
desc.value = name
Object.defineProperty(func, 'name', desc)
}
}
/**
* Populate the exports object with constructors for every error class.
* @private
*/
function populateConstructorExports (exports, codes, HttpError) {
codes.forEach(function forEachCode (code) {
var CodeError
var name = toIdentifier(statuses.message[code])
switch (codeClass(code)) {
case 400:
CodeError = createClientErrorConstructor(HttpError, name, code)
break
case 500:
CodeError = createServerErrorConstructor(HttpError, name, code)
break
}
if (CodeError) {
// export the constructor
exports[code] = CodeError
exports[name] = CodeError
}
})
}
/**
* Get a class name from a name identifier.
* @private
*/
function toClassName (name) {
return name.substr(-5) !== 'Error'
? name + 'Error'
: name
}