opusdev/vector-similarity-api

1/*!2 * http-errors3 * Copyright(c) 2014 Jonathan Ong4 * Copyright(c) 2016 Douglas Christopher Wilson5 * MIT Licensed6 */7 8'use strict'9 10/**11 * Module dependencies.12 * @private13 */14 15var deprecate = require('depd')('http-errors')16var setPrototypeOf = require('setprototypeof')17var statuses = require('statuses')18var inherits = require('inherits')19var toIdentifier = require('toidentifier')20 21/**22 * Module exports.23 * @public24 */25 26module.exports = createError27module.exports.HttpError = createHttpErrorConstructor()28module.exports.isHttpError = createIsHttpErrorFunction(module.exports.HttpError)29 30// Populate exports for all constructors31populateConstructorExports(module.exports, statuses.codes, module.exports.HttpError)32 33/**34 * Get the code class of a status code.35 * @private36 */37 38function codeClass (status) {39  return Number(String(status).charAt(0) + '00')40}41 42/**43 * Create a new HTTP Error.44 *45 * @returns {Error}46 * @public47 */48 49function createError () {50  // so much arity going on ~_~51  var err52  var msg53  var status = 50054  var props = {}55  for (var i = 0; i < arguments.length; i++) {56    var arg = arguments[i]57    var type = typeof arg58    if (type === 'object' && arg instanceof Error) {59      err = arg60      status = err.status || err.statusCode || status61    } else if (type === 'number' && i === 0) {62      status = arg63    } else if (type === 'string') {64      msg = arg65    } else if (type === 'object') {66      props = arg67    } else {68      throw new TypeError('argument #' + (i + 1) + ' unsupported type ' + type)69    }70  }71 72  if (typeof status === 'number' && (status < 400 || status >= 600)) {73    deprecate('non-error status code; use only 4xx or 5xx status codes')74  }75 76  if (typeof status !== 'number' ||77    (!statuses.message[status] && (status < 400 || status >= 600))) {78    status = 50079  }80 81  // constructor82  var HttpError = createError[status] || createError[codeClass(status)]83 84  if (!err) {85    // create error86    err = HttpError87      ? new HttpError(msg)88      : new Error(msg || statuses.message[status])89    Error.captureStackTrace(err, createError)90  }91 92  if (!HttpError || !(err instanceof HttpError) || err.status !== status) {93    // add properties to generic error94    err.expose = status < 50095    err.status = err.statusCode = status96  }97 98  for (var key in props) {99    if (key !== 'status' && key !== 'statusCode') {100      err[key] = props[key]101    }102  }103 104  return err105}106 107/**108 * Create HTTP error abstract base class.109 * @private110 */111 112function createHttpErrorConstructor () {113  function HttpError () {114    throw new TypeError('cannot construct abstract class')115  }116 117  inherits(HttpError, Error)118 119  return HttpError120}121 122/**123 * Create a constructor for a client error.124 * @private125 */126 127function createClientErrorConstructor (HttpError, name, code) {128  var className = toClassName(name)129 130  function ClientError (message) {131    // create the error object132    var msg = message != null ? message : statuses.message[code]133    var err = new Error(msg)134 135    // capture a stack trace to the construction point136    Error.captureStackTrace(err, ClientError)137 138    // adjust the [[Prototype]]139    setPrototypeOf(err, ClientError.prototype)140 141    // redefine the error message142    Object.defineProperty(err, 'message', {143      enumerable: true,144      configurable: true,145      value: msg,146      writable: true147    })148 149    // redefine the error name150    Object.defineProperty(err, 'name', {151      enumerable: false,152      configurable: true,153      value: className,154      writable: true155    })156 157    return err158  }159 160  inherits(ClientError, HttpError)161  nameFunc(ClientError, className)162 163  ClientError.prototype.status = code164  ClientError.prototype.statusCode = code165  ClientError.prototype.expose = true166 167  return ClientError168}169 170/**171 * Create function to test is a value is a HttpError.172 * @private173 */174 175function createIsHttpErrorFunction (HttpError) {176  return function isHttpError (val) {177    if (!val || typeof val !== 'object') {178      return false179    }180 181    if (val instanceof HttpError) {182      return true183    }184 185    return val instanceof Error &&186      typeof val.expose === 'boolean' &&187      typeof val.statusCode === 'number' && val.status === val.statusCode188  }189}190 191/**192 * Create a constructor for a server error.193 * @private194 */195 196function createServerErrorConstructor (HttpError, name, code) {197  var className = toClassName(name)198 199  function ServerError (message) {200    // create the error object201    var msg = message != null ? message : statuses.message[code]202    var err = new Error(msg)203 204    // capture a stack trace to the construction point205    Error.captureStackTrace(err, ServerError)206 207    // adjust the [[Prototype]]208    setPrototypeOf(err, ServerError.prototype)209 210    // redefine the error message211    Object.defineProperty(err, 'message', {212      enumerable: true,213      configurable: true,214      value: msg,215      writable: true216    })217 218    // redefine the error name219    Object.defineProperty(err, 'name', {220      enumerable: false,221      configurable: true,222      value: className,223      writable: true224    })225 226    return err227  }228 229  inherits(ServerError, HttpError)230  nameFunc(ServerError, className)231 232  ServerError.prototype.status = code233  ServerError.prototype.statusCode = code234  ServerError.prototype.expose = false235 236  return ServerError237}238 239/**240 * Set the name of a function, if possible.241 * @private242 */243 244function nameFunc (func, name) {245  var desc = Object.getOwnPropertyDescriptor(func, 'name')246 247  if (desc && desc.configurable) {248    desc.value = name249    Object.defineProperty(func, 'name', desc)250  }251}252 253/**254 * Populate the exports object with constructors for every error class.255 * @private256 */257 258function populateConstructorExports (exports, codes, HttpError) {259  codes.forEach(function forEachCode (code) {260    var CodeError261    var name = toIdentifier(statuses.message[code])262 263    switch (codeClass(code)) {264      case 400:265        CodeError = createClientErrorConstructor(HttpError, name, code)266        break267      case 500:268        CodeError = createServerErrorConstructor(HttpError, name, code)269        break270    }271 272    if (CodeError) {273      // export the constructor274      exports[code] = CodeError275      exports[name] = CodeError276    }277  })278}279 280/**281 * Get a class name from a name identifier.282 *283 * @param {string} name284 * @returns {string}285 * @private286 */287 288function toClassName (name) {289  return name.slice(-5) === 'Error' ? name : name + 'Error'290}291