/*!
* encodeurl
* Copyright(c) 2016 Douglas Christopher Wilson
* MIT Licensed
*/
'use strict'
/**
* Module exports.
* @public
*/
module.exports = encodeUrl
/**
* RegExp to match non-URL code points, *after* encoding (i.e. not including "%")
* and including invalid escape sequences.
* @private
*/
var ENCODE_CHARS_REGEXP = /(?:[^\x21\x25\x26-\x3B\x3D\x3F-\x5B\x5D\x5F\x61-\x7A\x7E]|%(?:[^0-9A-Fa-f]|[0-9A-Fa-f][^0-9A-Fa-f]|$))+/g
/**
* RegExp to match unmatched surrogate pair.
* @private
*/
var UNMATCHED_SURROGATE_PAIR_REGEXP = /(^|[^\uD800-\uDBFF])[\uDC00-\uDFFF]|[\uD800-\uDBFF]([^\uDC00-\uDFFF]|$)/g
/**
* String to replace unmatched surrogate pair with.
* @private
*/
var UNMATCHED_SURROGATE_PAIR_REPLACE = '$1\uFFFD$2'
/**
* Encode a URL to a percent-encoded form, excluding already-encoded sequences.
*
* This function will take an already-encoded URL and encode all the non-URL
* code points. This function will not encode the "%" character unless it is
* not part of a valid sequence (`%20` will be left as-is, but `%foo` will
* be encoded as `%25foo`).
*
* This encode is meant to be "safe" and does not throw errors. It will try as
* hard as it can to properly encode the given URL, including replacing any raw,
* unpaired surrogate pairs with the Unicode replacement character prior to
* encoding.
*
* @param {string} url
* @return {string}
* @public
*/
function encodeUrl (url) {
return String(url)
.replace(UNMATCHED_SURROGATE_PAIR_REGEXP, UNMATCHED_SURROGATE_PAIR_REPLACE)
.replace(ENCODE_CHARS_REGEXP, encodeURI)
}