[6a3a178] | 1 | /*!
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| 2 | * type-is
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| 3 | * Copyright(c) 2014 Jonathan Ong
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| 4 | * Copyright(c) 2014-2015 Douglas Christopher Wilson
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| 5 | * MIT Licensed
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| 6 | */
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| 7 |
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| 8 | 'use strict'
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| 9 |
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| 10 | /**
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| 11 | * Module dependencies.
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| 12 | * @private
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| 13 | */
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| 14 |
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| 15 | var typer = require('media-typer')
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| 16 | var mime = require('mime-types')
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| 17 |
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| 18 | /**
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| 19 | * Module exports.
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| 20 | * @public
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| 21 | */
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| 22 |
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| 23 | module.exports = typeofrequest
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| 24 | module.exports.is = typeis
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| 25 | module.exports.hasBody = hasbody
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| 26 | module.exports.normalize = normalize
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| 27 | module.exports.match = mimeMatch
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| 28 |
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| 29 | /**
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| 30 | * Compare a `value` content-type with `types`.
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| 31 | * Each `type` can be an extension like `html`,
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| 32 | * a special shortcut like `multipart` or `urlencoded`,
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| 33 | * or a mime type.
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| 34 | *
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| 35 | * If no types match, `false` is returned.
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| 36 | * Otherwise, the first `type` that matches is returned.
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| 37 | *
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| 38 | * @param {String} value
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| 39 | * @param {Array} types
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| 40 | * @public
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| 41 | */
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| 42 |
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| 43 | function typeis (value, types_) {
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| 44 | var i
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| 45 | var types = types_
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| 46 |
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| 47 | // remove parameters and normalize
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| 48 | var val = tryNormalizeType(value)
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| 49 |
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| 50 | // no type or invalid
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| 51 | if (!val) {
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| 52 | return false
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| 53 | }
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| 54 |
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| 55 | // support flattened arguments
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| 56 | if (types && !Array.isArray(types)) {
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| 57 | types = new Array(arguments.length - 1)
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| 58 | for (i = 0; i < types.length; i++) {
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| 59 | types[i] = arguments[i + 1]
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| 60 | }
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| 61 | }
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| 62 |
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| 63 | // no types, return the content type
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| 64 | if (!types || !types.length) {
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| 65 | return val
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| 66 | }
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| 67 |
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| 68 | var type
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| 69 | for (i = 0; i < types.length; i++) {
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| 70 | if (mimeMatch(normalize(type = types[i]), val)) {
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| 71 | return type[0] === '+' || type.indexOf('*') !== -1
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| 72 | ? val
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| 73 | : type
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| 74 | }
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| 75 | }
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| 76 |
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| 77 | // no matches
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| 78 | return false
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| 79 | }
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| 80 |
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| 81 | /**
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| 82 | * Check if a request has a request body.
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| 83 | * A request with a body __must__ either have `transfer-encoding`
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| 84 | * or `content-length` headers set.
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| 85 | * http://www.w3.org/Protocols/rfc2616/rfc2616-sec4.html#sec4.3
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| 86 | *
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| 87 | * @param {Object} request
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| 88 | * @return {Boolean}
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| 89 | * @public
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| 90 | */
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| 91 |
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| 92 | function hasbody (req) {
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| 93 | return req.headers['transfer-encoding'] !== undefined ||
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| 94 | !isNaN(req.headers['content-length'])
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| 95 | }
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| 96 |
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| 97 | /**
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| 98 | * Check if the incoming request contains the "Content-Type"
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| 99 | * header field, and it contains any of the give mime `type`s.
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| 100 | * If there is no request body, `null` is returned.
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| 101 | * If there is no content type, `false` is returned.
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| 102 | * Otherwise, it returns the first `type` that matches.
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| 103 | *
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| 104 | * Examples:
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| 105 | *
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| 106 | * // With Content-Type: text/html; charset=utf-8
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| 107 | * this.is('html'); // => 'html'
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| 108 | * this.is('text/html'); // => 'text/html'
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| 109 | * this.is('text/*', 'application/json'); // => 'text/html'
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| 110 | *
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| 111 | * // When Content-Type is application/json
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| 112 | * this.is('json', 'urlencoded'); // => 'json'
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| 113 | * this.is('application/json'); // => 'application/json'
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| 114 | * this.is('html', 'application/*'); // => 'application/json'
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| 115 | *
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| 116 | * this.is('html'); // => false
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| 117 | *
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| 118 | * @param {String|Array} types...
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| 119 | * @return {String|false|null}
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| 120 | * @public
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| 121 | */
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| 122 |
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| 123 | function typeofrequest (req, types_) {
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| 124 | var types = types_
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| 125 |
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| 126 | // no body
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| 127 | if (!hasbody(req)) {
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| 128 | return null
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| 129 | }
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| 130 |
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| 131 | // support flattened arguments
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| 132 | if (arguments.length > 2) {
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| 133 | types = new Array(arguments.length - 1)
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| 134 | for (var i = 0; i < types.length; i++) {
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| 135 | types[i] = arguments[i + 1]
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| 136 | }
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| 137 | }
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| 138 |
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| 139 | // request content type
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| 140 | var value = req.headers['content-type']
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| 141 |
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| 142 | return typeis(value, types)
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| 143 | }
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| 144 |
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| 145 | /**
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| 146 | * Normalize a mime type.
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| 147 | * If it's a shorthand, expand it to a valid mime type.
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| 148 | *
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| 149 | * In general, you probably want:
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| 150 | *
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| 151 | * var type = is(req, ['urlencoded', 'json', 'multipart']);
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| 152 | *
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| 153 | * Then use the appropriate body parsers.
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| 154 | * These three are the most common request body types
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| 155 | * and are thus ensured to work.
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| 156 | *
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| 157 | * @param {String} type
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| 158 | * @private
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| 159 | */
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| 160 |
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| 161 | function normalize (type) {
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| 162 | if (typeof type !== 'string') {
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| 163 | // invalid type
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| 164 | return false
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| 165 | }
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| 166 |
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| 167 | switch (type) {
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| 168 | case 'urlencoded':
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| 169 | return 'application/x-www-form-urlencoded'
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| 170 | case 'multipart':
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| 171 | return 'multipart/*'
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| 172 | }
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| 173 |
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| 174 | if (type[0] === '+') {
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| 175 | // "+json" -> "*/*+json" expando
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| 176 | return '*/*' + type
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| 177 | }
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| 178 |
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| 179 | return type.indexOf('/') === -1
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| 180 | ? mime.lookup(type)
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| 181 | : type
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| 182 | }
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| 183 |
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| 184 | /**
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| 185 | * Check if `expected` mime type
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| 186 | * matches `actual` mime type with
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| 187 | * wildcard and +suffix support.
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| 188 | *
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| 189 | * @param {String} expected
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| 190 | * @param {String} actual
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| 191 | * @return {Boolean}
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| 192 | * @private
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| 193 | */
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| 194 |
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| 195 | function mimeMatch (expected, actual) {
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| 196 | // invalid type
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| 197 | if (expected === false) {
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| 198 | return false
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| 199 | }
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| 200 |
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| 201 | // split types
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| 202 | var actualParts = actual.split('/')
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| 203 | var expectedParts = expected.split('/')
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| 204 |
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| 205 | // invalid format
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| 206 | if (actualParts.length !== 2 || expectedParts.length !== 2) {
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| 207 | return false
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| 208 | }
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| 209 |
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| 210 | // validate type
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| 211 | if (expectedParts[0] !== '*' && expectedParts[0] !== actualParts[0]) {
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| 212 | return false
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| 213 | }
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| 214 |
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| 215 | // validate suffix wildcard
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| 216 | if (expectedParts[1].substr(0, 2) === '*+') {
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| 217 | return expectedParts[1].length <= actualParts[1].length + 1 &&
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| 218 | expectedParts[1].substr(1) === actualParts[1].substr(1 - expectedParts[1].length)
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| 219 | }
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| 220 |
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| 221 | // validate subtype
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| 222 | if (expectedParts[1] !== '*' && expectedParts[1] !== actualParts[1]) {
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| 223 | return false
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| 224 | }
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| 225 |
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| 226 | return true
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| 227 | }
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| 228 |
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| 229 | /**
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| 230 | * Normalize a type and remove parameters.
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| 231 | *
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| 232 | * @param {string} value
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| 233 | * @return {string}
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| 234 | * @private
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| 235 | */
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| 236 |
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| 237 | function normalizeType (value) {
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| 238 | // parse the type
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| 239 | var type = typer.parse(value)
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| 240 |
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| 241 | // remove the parameters
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| 242 | type.parameters = undefined
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| 243 |
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| 244 | // reformat it
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| 245 | return typer.format(type)
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| 246 | }
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| 247 |
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| 248 | /**
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| 249 | * Try to normalize a type and remove parameters.
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| 250 | *
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| 251 | * @param {string} value
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| 252 | * @return {string}
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| 253 | * @private
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| 254 | */
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| 255 |
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| 256 | function tryNormalizeType (value) {
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| 257 | if (!value) {
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| 258 | return null
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| 259 | }
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| 260 |
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| 261 | try {
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| 262 | return normalizeType(value)
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| 263 | } catch (err) {
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| 264 | return null
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| 265 | }
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| 266 | }
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