CoCalc -- index.js

cocalc/src / smc-project / node_modules / finalhandler / index.js
⁵⁰⁶⁵⁵ views
1
/*!
2
 * finalhandler
3
 * Copyright(c) 2014-2017 Douglas Christopher Wilson
4
 * MIT Licensed
5
 */
6

7
'use strict'
8

9
/**
10
 * Module dependencies.
11
 * @private
12
 */
13

14
var debug = require('debug')('finalhandler')
15
var encodeUrl = require('encodeurl')
16
var escapeHtml = require('escape-html')
17
var onFinished = require('on-finished')
18
var parseUrl = require('parseurl')
19
var statuses = require('statuses')
20
var unpipe = require('unpipe')
21

22
/**
23
 * Module variables.
24
 * @private
25
 */
26

27
var DOUBLE_SPACE_REGEXP = /\x20{2}/g
28
var NEWLINE_REGEXP = /\n/g
29

30
/* istanbul ignore next */
31
var defer = typeof setImmediate === 'function'
32
  ? setImmediate
33
  : function (fn) { process.nextTick(fn.bind.apply(fn, arguments)) }
34
var isFinished = onFinished.isFinished
35

36
/**
37
 * Create a minimal HTML document.
38
 *
39
 * @param {string} message
40
 * @private
41
 */
42

43
function createHtmlDocument (message) {
44
  var body = escapeHtml(message)
45
    .replace(NEWLINE_REGEXP, '<br>')
46
    .replace(DOUBLE_SPACE_REGEXP, ' &nbsp;')
47

48
  return '<!DOCTYPE html>\n' +
49
    '<html lang="en">\n' +
50
    '<head>\n' +
51
    '<meta charset="utf-8">\n' +
52
    '<title>Error</title>\n' +
53
    '</head>\n' +
54
    '<body>\n' +
55
    '<pre>' + body + '</pre>\n' +
56
    '</body>\n' +
57
    '</html>\n'
58
}
59

60
/**
61
 * Module exports.
62
 * @public
63
 */
64

65
module.exports = finalhandler
66

67
/**
68
 * Create a function to handle the final response.
69
 *
70
 * @param {Request} req
71
 * @param {Response} res
72
 * @param {Object} [options]
73
 * @return {Function}
74
 * @public
75
 */
76

77
function finalhandler (req, res, options) {
78
  var opts = options || {}
79

80
  // get environment
81
  var env = opts.env || process.env.NODE_ENV || 'development'
82

83
  // get error callback
84
  var onerror = opts.onerror
85

86
  return function (err) {
87
    var headers
88
    var msg
89
    var status
90

91
    // ignore 404 on in-flight response
92
    if (!err && res._header) {
93
      debug('cannot 404 after headers sent')
94
      return
95
    }
96

97
    // unhandled error
98
    if (err) {
99
      // respect status code from error
100
      status = getErrorStatusCode(err)
101

102
      // respect headers from error
103
      if (status !== undefined) {
104
        headers = getErrorHeaders(err)
105
      }
106

107
      // fallback to status code on response
108
      if (status === undefined) {
109
        status = getResponseStatusCode(res)
110
      }
111

112
      // get error message
113
      msg = getErrorMessage(err, status, env)
114
    } else {
115
      // not found
116
      status = 404
117
      msg = 'Cannot ' + req.method + ' ' + encodeUrl(parseUrl.original(req).pathname)
118
    }
119

120
    debug('default %s', status)
121

122
    // schedule onerror callback
123
    if (err && onerror) {
124
      defer(onerror, err, req, res)
125
    }
126

127
    // cannot actually respond
128
    if (res._header) {
129
      debug('cannot %d after headers sent', status)
130
      req.socket.destroy()
131
      return
132
    }
133

134
    // send response
135
    send(req, res, status, headers, msg)
136
  }
137
}
138

139
/**
140
 * Get headers from Error object.
141
 *
142
 * @param {Error} err
143
 * @return {object}
144
 * @private
145
 */
146

147
function getErrorHeaders (err) {
148
  if (!err.headers || typeof err.headers !== 'object') {
149
    return undefined
150
  }
151

152
  var headers = Object.create(null)
153
  var keys = Object.keys(err.headers)
154

155
  for (var i = 0; i < keys.length; i++) {
156
    var key = keys[i]
157
    headers[key] = err.headers[key]
158
  }
159

160
  return headers
161
}
162

163
/**
164
 * Get message from Error object, fallback to status message.
165
 *
166
 * @param {Error} err
167
 * @param {number} status
168
 * @param {string} env
169
 * @return {string}
170
 * @private
171
 */
172

173
function getErrorMessage (err, status, env) {
174
  var msg
175

176
  if (env !== 'production') {
177
    // use err.stack, which typically includes err.message
178
    msg = err.stack
179

180
    // fallback to err.toString() when possible
181
    if (!msg && typeof err.toString === 'function') {
182
      msg = err.toString()
183
    }
184
  }
185

186
  return msg || statuses[status]
187
}
188

189
/**
190
 * Get status code from Error object.
191
 *
192
 * @param {Error} err
193
 * @return {number}
194
 * @private
195
 */
196

197
function getErrorStatusCode (err) {
198
  // check err.status
199
  if (typeof err.status === 'number' && err.status >= 400 && err.status < 600) {
200
    return err.status
201
  }
202

203
  // check err.statusCode
204
  if (typeof err.statusCode === 'number' && err.statusCode >= 400 && err.statusCode < 600) {
205
    return err.statusCode
206
  }
207

208
  return undefined
209
}
210

211
/**
212
 * Get status code from response.
213
 *
214
 * @param {OutgoingMessage} res
215
 * @return {number}
216
 * @private
217
 */
218

219
function getResponseStatusCode (res) {
220
  var status = res.statusCode
221

222
  // default status code to 500 if outside valid range
223
  if (typeof status !== 'number' || status < 400 || status > 599) {
224
    status = 500
225
  }
226

227
  return status
228
}
229

230
/**
231
 * Send response.
232
 *
233
 * @param {IncomingMessage} req
234
 * @param {OutgoingMessage} res
235
 * @param {number} status
236
 * @param {object} headers
237
 * @param {string} message
238
 * @private
239
 */
240

241
function send (req, res, status, headers, message) {
242
  function write () {
243
    // response body
244
    var body = createHtmlDocument(message)
245

246
    // response status
247
    res.statusCode = status
248
    res.statusMessage = statuses[status]
249

250
    // response headers
251
    setHeaders(res, headers)
252

253
    // security headers
254
    res.setHeader('Content-Security-Policy', "default-src 'self'")
255
    res.setHeader('X-Content-Type-Options', 'nosniff')
256

257
    // standard headers
258
    res.setHeader('Content-Type', 'text/html; charset=utf-8')
259
    res.setHeader('Content-Length', Buffer.byteLength(body, 'utf8'))
260

261
    if (req.method === 'HEAD') {
262
      res.end()
263
      return
264
    }
265

266
    res.end(body, 'utf8')
267
  }
268

269
  if (isFinished(req)) {
270
    write()
271
    return
272
  }
273

274
  // unpipe everything from the request
275
  unpipe(req)
276

277
  // flush the request
278
  onFinished(req, write)
279
  req.resume()
280
}
281

282
/**
283
 * Set response headers from an object.
284
 *
285
 * @param {OutgoingMessage} res
286
 * @param {object} headers
287
 * @private
288
 */
289

290
function setHeaders (res, headers) {
291
  if (!headers) {
292
    return
293
  }
294

295
  var keys = Object.keys(headers)
296
  for (var i = 0; i < keys.length; i++) {
297
    var key = keys[i]
298
    res.setHeader(key, headers[key])
299
  }
300
}
301

302
Product

Resources

Company
