1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
|
/*!
* 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)
// respect headers from error
if (status !== undefined) {
headers = getErrorHeaders(err)
}
// fallback to status code on response
if (status === undefined) {
status = getResponseStatusCode(res)
}
// get error message
msg = getErrorMessage(err, status, env)
} else {
// not found
status = 404
msg = 'Cannot ' + req.method + ' ' + encodeUrl(parseUrl.original(req).pathname)
}
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 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])
}
}
|
