alpcentaur
/
permapp

/*! * finalhandler * Copyright(c) 2014-2017 Douglas Christopher Wilson * MIT Licensed */
'use strict'
/** * Module dependencies. * @private */
var debug = require('debug')('finalhandler')var encodeUrl = require('encodeurl')var escapeHtml = require('escape-html')var onFinished = require('on-finished')var parseUrl = require('parseurl')var statuses = require('statuses')var unpipe = require('unpipe')
/** * Module variables. * @private */
var DOUBLE_SPACE_REGEXP = /\x20{2}/gvar NEWLINE_REGEXP = /\n/g
/* istanbul ignore next */var defer = typeof setImmediate === 'function'  ? setImmediate  : function (fn) { process.nextTick(fn.bind.apply(fn, arguments)) }var isFinished = onFinished.isFinished
/** * Create a minimal HTML document. * * @param {string} message * @private */
function createHtmlDocument (message) {  var body = escapeHtml(message)    .replace(NEWLINE_REGEXP, '<br>')    .replace(DOUBLE_SPACE_REGEXP, ' &nbsp;')
  return '<!DOCTYPE html>\n' +    '<html lang="en">\n' +    '<head>\n' +    '<meta charset="utf-8">\n' +    '<title>Error</title>\n' +    '</head>\n' +    '<body>\n' +    '<pre>' + body + '</pre>\n' +    '</body>\n' +    '</html>\n'}
/** * Module exports. * @public */
module.exports = finalhandler
/** * Create a function to handle the final response. * * @param {Request} req * @param {Response} res * @param {Object} [options] * @return {Function} * @public */
function finalhandler (req, res, options) {  var opts = options || {}
  // get environment
  var env = opts.env || process.env.NODE_ENV || 'development'
  // get error callback
  var onerror = opts.onerror
  return function (err) {    var headers    var msg    var status
    // ignore 404 on in-flight response
    if (!err && headersSent(res)) {      debug('cannot 404 after headers sent')      return    }
    // unhandled error
    if (err) {      // respect status code from error
      status = getErrorStatusCode(err)
      if (status === undefined) {        // fallback to status code on response
        status = getResponseStatusCode(res)      } else {        // respect headers from error
        headers = getErrorHeaders(err)      }
      // get error message
      msg = getErrorMessage(err, status, env)    } else {      // not found
      status = 404      msg = 'Cannot ' + req.method + ' ' + encodeUrl(getResourceName(req))    }
    debug('default %s', status)
    // schedule onerror callback
    if (err && onerror) {      defer(onerror, err, req, res)    }
    // cannot actually respond
    if (headersSent(res)) {      debug('cannot %d after headers sent', status)      req.socket.destroy()      return    }
    // send response
    send(req, res, status, headers, msg)  }}
/** * Get headers from Error object. * * @param {Error} err * @return {object} * @private */
function getErrorHeaders (err) {  if (!err.headers || typeof err.headers !== 'object') {    return undefined  }
  var headers = Object.create(null)  var keys = Object.keys(err.headers)
  for (var i = 0; i < keys.length; i++) {    var key = keys[i]    headers[key] = err.headers[key]  }
  return headers}
/** * Get message from Error object, fallback to status message. * * @param {Error} err * @param {number} status * @param {string} env * @return {string} * @private */
function getErrorMessage (err, status, env) {  var msg
  if (env !== 'production') {    // use err.stack, which typically includes err.message
    msg = err.stack
    // fallback to err.toString() when possible
    if (!msg && typeof err.toString === 'function') {      msg = err.toString()    }  }
  return msg || statuses[status]}
/** * Get status code from Error object. * * @param {Error} err * @return {number} * @private */
function getErrorStatusCode (err) {  // check err.status
  if (typeof err.status === 'number' && err.status >= 400 && err.status < 600) {    return err.status  }
  // check err.statusCode
  if (typeof err.statusCode === 'number' && err.statusCode >= 400 && err.statusCode < 600) {    return err.statusCode  }
  return undefined}
/** * Get resource name for the request. * * This is typically just the original pathname of the request * but will fallback to "resource" is that cannot be determined. * * @param {IncomingMessage} req * @return {string} * @private */
function getResourceName (req) {  try {    return parseUrl.original(req).pathname  } catch (e) {    return 'resource'  }}
/** * Get status code from response. * * @param {OutgoingMessage} res * @return {number} * @private */
function getResponseStatusCode (res) {  var status = res.statusCode
  // default status code to 500 if outside valid range
  if (typeof status !== 'number' || status < 400 || status > 599) {    status = 500  }
  return status}
/** * Determine if the response headers have been sent. * * @param {object} res * @returns {boolean} * @private */
function headersSent (res) {  return typeof res.headersSent !== 'boolean'    ? Boolean(res._header)    : res.headersSent}
/** * Send response. * * @param {IncomingMessage} req * @param {OutgoingMessage} res * @param {number} status * @param {object} headers * @param {string} message * @private */
function send (req, res, status, headers, message) {  function write () {    // response body
    var body = createHtmlDocument(message)
    // response status
    res.statusCode = status    res.statusMessage = statuses[status]
    // response headers
    setHeaders(res, headers)
    // security headers
    res.setHeader('Content-Security-Policy', "default-src 'none'")    res.setHeader('X-Content-Type-Options', 'nosniff')
    // standard headers
    res.setHeader('Content-Type', 'text/html; charset=utf-8')    res.setHeader('Content-Length', Buffer.byteLength(body, 'utf8'))
    if (req.method === 'HEAD') {      res.end()      return    }
    res.end(body, 'utf8')  }
  if (isFinished(req)) {    write()    return  }
  // unpipe everything from the request
  unpipe(req)
  // flush the request
  onFinished(req, write)  req.resume()}
/** * Set response headers from an object. * * @param {OutgoingMessage} res * @param {object} headers * @private */
function setHeaders (res, headers) {  if (!headers) {    return  }
  var keys = Object.keys(headers)  for (var i = 0; i < keys.length; i++) {    var key = keys[i]    res.setHeader(key, headers[key])  }}