--- /dev/null
+/*!
+ * 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}/g
+var 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, ' ')
+
+ 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 'self'")
+ 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])
+ }
+}
projects / josuexyz / .git / blobdiff