source: trip-planner-front/node_modules/vary/index.js@ 1ad8e64

Last change on this file since 1ad8e64 was 6a3a178, checked in by Ema <ema_spirova@…>, 3 years ago

initial commit

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Line 
1/*!
2 * vary
3 * Copyright(c) 2014-2017 Douglas Christopher Wilson
4 * MIT Licensed
5 */
6
7'use strict'
8
9/**
10 * Module exports.
11 */
12
13module.exports = vary
14module.exports.append = append
15
16/**
17 * RegExp to match field-name in RFC 7230 sec 3.2
18 *
19 * field-name = token
20 * token = 1*tchar
21 * tchar = "!" / "#" / "$" / "%" / "&" / "'" / "*"
22 * / "+" / "-" / "." / "^" / "_" / "`" / "|" / "~"
23 * / DIGIT / ALPHA
24 * ; any VCHAR, except delimiters
25 */
26
27var FIELD_NAME_REGEXP = /^[!#$%&'*+\-.^_`|~0-9A-Za-z]+$/
28
29/**
30 * Append a field to a vary header.
31 *
32 * @param {String} header
33 * @param {String|Array} field
34 * @return {String}
35 * @public
36 */
37
38function append (header, field) {
39 if (typeof header !== 'string') {
40 throw new TypeError('header argument is required')
41 }
42
43 if (!field) {
44 throw new TypeError('field argument is required')
45 }
46
47 // get fields array
48 var fields = !Array.isArray(field)
49 ? parse(String(field))
50 : field
51
52 // assert on invalid field names
53 for (var j = 0; j < fields.length; j++) {
54 if (!FIELD_NAME_REGEXP.test(fields[j])) {
55 throw new TypeError('field argument contains an invalid header name')
56 }
57 }
58
59 // existing, unspecified vary
60 if (header === '*') {
61 return header
62 }
63
64 // enumerate current values
65 var val = header
66 var vals = parse(header.toLowerCase())
67
68 // unspecified vary
69 if (fields.indexOf('*') !== -1 || vals.indexOf('*') !== -1) {
70 return '*'
71 }
72
73 for (var i = 0; i < fields.length; i++) {
74 var fld = fields[i].toLowerCase()
75
76 // append value (case-preserving)
77 if (vals.indexOf(fld) === -1) {
78 vals.push(fld)
79 val = val
80 ? val + ', ' + fields[i]
81 : fields[i]
82 }
83 }
84
85 return val
86}
87
88/**
89 * Parse a vary header into an array.
90 *
91 * @param {String} header
92 * @return {Array}
93 * @private
94 */
95
96function parse (header) {
97 var end = 0
98 var list = []
99 var start = 0
100
101 // gather tokens
102 for (var i = 0, len = header.length; i < len; i++) {
103 switch (header.charCodeAt(i)) {
104 case 0x20: /* */
105 if (start === end) {
106 start = end = i + 1
107 }
108 break
109 case 0x2c: /* , */
110 list.push(header.substring(start, end))
111 start = end = i + 1
112 break
113 default:
114 end = i + 1
115 break
116 }
117 }
118
119 // final token
120 list.push(header.substring(start, end))
121
122 return list
123}
124
125/**
126 * Mark that a request is varied on a header field.
127 *
128 * @param {Object} res
129 * @param {String|Array} field
130 * @public
131 */
132
133function vary (res, field) {
134 if (!res || !res.getHeader || !res.setHeader) {
135 // quack quack
136 throw new TypeError('res argument is required')
137 }
138
139 // get existing header
140 var val = res.getHeader('Vary') || ''
141 var header = Array.isArray(val)
142 ? val.join(', ')
143 : String(val)
144
145 // set new header
146 if ((val = append(header, field))) {
147 res.setHeader('Vary', val)
148 }
149}
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