node-restify-errors/lib/http_error.js

The Restify Errors Methods as a separate Module.

// Copyright 2012 Mark Cavage, Inc.  All rights reserved.

var http = require('http');
var util = require('util');



///--- Helpers

function codeToErrorName(code) {
  if (!code)
    throw new TypeError('code (Number) required');

  code = parseInt(code, 10);
  var status = http.STATUS_CODES[code];
  if (!status) {
    // Until https://github.com/joyent/node/pull/2371 is in
    if (code === 428) {
      status = 'Precondition Required';
    } else if (code === 429) {
      status = 'Too Many Requests';
    } else if (code === 431) {
      status = 'Request Header Fields Too Large';
    } else if (code === 511) {
      status = 'Network Authentication Required';
    } else {
      return false;
    }
  }


  var pieces = status.split(/\s+/);
  var str = '';
  pieces.forEach(function (s) {
    str += s.charAt(0).toUpperCase() + s.slice(1).toLowerCase();
  });

  str = str.replace(/\W+/g, '');
  if (!/\w+Error$/.test(str))
    str += 'Error';

  return str;
}



///--- Error Base class

function HttpError(code, message, body, constructorOpt) {
  if (Error.captureStackTrace)
    Error.captureStackTrace(this, constructorOpt || HttpError);

  code = parseInt(code, 10);

  this.message = message || '';
  this.body = body || (message ? { message: message } : '');
  this.statusCode = this.httpCode = code;
}
util.inherits(HttpError, Error);
HttpError.prototype.name = 'HttpError';



///--- Exports

module.exports = {

  HttpError: HttpError,

  codeToHttpError: function codeToHttpError(code, message, body) {
    var name = codeToErrorName(code);
    if (!name)
      throw new Error(code + ' is not a known HTTP error code');

    return new module.exports[name](message, body, codeToHttpError);
  }

};



// Export all the 4xx and 5xx HTTP Status codes as Errors

var codes = Object.keys(http.STATUS_CODES);

// Until https://github.com/joyent/node/pull/2371 is in
codes.push(428, 429, 431, 511);
codes.forEach(function (code) {
  if (code < 400)
    return;

  var name = codeToErrorName(code);

  module.exports[name] = function (message, body, caller) {
    HttpError.call(this,
                   code,
                   message,
                   body || null,
                   caller || this.constructor);
  };
  util.inherits(module.exports[name], HttpError);
  module.exports[name].displayName = module.exports[name].prototype.name = name;
});