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/*!
* content-type
* Copyright(c) 2015 Douglas Christopher Wilson
* MIT Licensed
*/
'use strict'
/**
* RegExp to match *( ";" parameter ) in RFC 7231 sec 3.1.1.1
*
* parameter = token "=" ( token / quoted-string )
* token = 1*tchar
* tchar = "!" / "#" / "$" / "%" / "&" / "'" / "*"
* / "+" / "-" / "." / "^" / "_" / "`" / "|" / "~"
* / DIGIT / ALPHA
* ; any VCHAR, except delimiters
* quoted-string = DQUOTE *( qdtext / quoted-pair ) DQUOTE
* qdtext = HTAB / SP / %x21 / %x23-5B / %x5D-7E / obs-text
* obs-text = %x80-FF
* quoted-pair = "\" ( HTAB / SP / VCHAR / obs-text )
*/
var PARAM_REGEXP = /; *([!#$%&'*+.^_`|~0-9A-Za-z-]+) *= *("(?:[\u000b\u0020\u0021\u0023-\u005b\u005d-\u007e\u0080-\u00ff]|\\[\u000b\u0020-\u00ff])*"|[!#$%&'*+.^_`|~0-9A-Za-z-]+) */g // eslint-disable-line no-control-regex
var TEXT_REGEXP = /^[\u000b\u0020-\u007e\u0080-\u00ff]+$/ // eslint-disable-line no-control-regex
var TOKEN_REGEXP = /^[!#$%&'*+.^_`|~0-9A-Za-z-]+$/
/**
* RegExp to match quoted-pair in RFC 7230 sec 3.2.6
*
* quoted-pair = "\" ( HTAB / SP / VCHAR / obs-text )
* obs-text = %x80-FF
*/
var QESC_REGEXP = /\\([\u000b\u0020-\u00ff])/g // eslint-disable-line no-control-regex
/**
* RegExp to match chars that must be quoted-pair in RFC 7230 sec 3.2.6
*/
var QUOTE_REGEXP = /([\\"])/g
/**
* RegExp to match type in RFC 7231 sec 3.1.1.1
*
* media-type = type "/" subtype
* type = token
* subtype = token
*/
var TYPE_REGEXP = /^[!#$%&'*+.^_`|~0-9A-Za-z-]+\/[!#$%&'*+.^_`|~0-9A-Za-z-]+$/
/**
* Module exports.
* @public
*/
exports.format = format
exports.parse = parse
/**
* Format object to media type.
*
* @param {object} obj
* @return {string}
* @public
*/
function format (obj) {
if (!obj || typeof obj !== 'object') {
throw new TypeError('argument obj is required')
}
var parameters = obj.parameters
var type = obj.type
if (!type || !TYPE_REGEXP.test(type)) {
throw new TypeError('invalid type')
}
var string = type
// append parameters
if (parameters && typeof parameters === 'object') {
var param
var params = Object.keys(parameters).sort()
for (var i = 0; i < params.length; i++) {
param = params[i]
if (!TOKEN_REGEXP.test(param)) {
throw new TypeError('invalid parameter name')
}
string += '; ' + param + '=' + qstring(parameters[param])
}
}
return string
}
/**
* Parse media type to object.
*
* @param {string|object} string
* @return {Object}
* @public
*/
function parse (string) {
if (!string) {
throw new TypeError('argument string is required')
}
// support req/res-like objects as argument
var header = typeof string === 'object'
? getcontenttype(string)
: string
if (typeof header !== 'string') {
throw new TypeError('argument string is required to be a string')
}
var index = header.indexOf(';')
var type = index !== -1
? header.slice(0, index).trim()
: header.trim()
if (!TYPE_REGEXP.test(type)) {
throw new TypeError('invalid media type')
}
var obj = new ContentType(type.toLowerCase())
// parse parameters
if (index !== -1) {
var key
var match
var value
PARAM_REGEXP.lastIndex = index
while ((match = PARAM_REGEXP.exec(header))) {
if (match.index !== index) {
throw new TypeError('invalid parameter format')
}
index += match[0].length
key = match[1].toLowerCase()
value = match[2]
if (value.charCodeAt(0) === 0x22 /* " */) {
// remove quotes
value = value.slice(1, -1)
// remove escapes
if (value.indexOf('\\') !== -1) {
value = value.replace(QESC_REGEXP, '$1')
}
}
obj.parameters[key] = value
}
if (index !== header.length) {
throw new TypeError('invalid parameter format')
}
}
return obj
}
/**
* Get content-type from req/res objects.
*
* @param {object}
* @return {Object}
* @private
*/
function getcontenttype (obj) {
var header
if (typeof obj.getHeader === 'function') {
// res-like
header = obj.getHeader('content-type')
} else if (typeof obj.headers === 'object') {
// req-like
header = obj.headers && obj.headers['content-type']
}
if (typeof header !== 'string') {
throw new TypeError('content-type header is missing from object')
}
return header
}
/**
* Quote a string if necessary.
*
* @param {string} val
* @return {string}
* @private
*/
function qstring (val) {
var str = String(val)
// no need to quote tokens
if (TOKEN_REGEXP.test(str)) {
return str
}
if (str.length > 0 && !TEXT_REGEXP.test(str)) {
throw new TypeError('invalid parameter value')
}
return '"' + str.replace(QUOTE_REGEXP, '\\$1') + '"'
}
/**
* Class to represent a content type.
* @private
*/
function ContentType (type) {
this.parameters = Object.create(null)
this.type = type
}