string-kit/lib/escape.js

A string manipulation toolbox, featuring a string formatter (inspired by sprintf), a variable inspector (output featuring ANSI colors and HTML) and various escape functions (shell argument, regexp, html, etc).

/*
	String Kit

	Copyright (c) 2014 - 2021 Cédric Ronvel

	The MIT License (MIT)

	Permission is hereby granted, free of charge, to any person obtaining a copy
	of this software and associated documentation files (the "Software"), to deal
	in the Software without restriction, including without limitation the rights
	to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
	copies of the Software, and to permit persons to whom the Software is
	furnished to do so, subject to the following conditions:

	The above copyright notice and this permission notice shall be included in all
	copies or substantial portions of the Software.

	THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
	AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
	OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
	SOFTWARE.
*/

/*
	Escape collection.
*/



"use strict" ;



// From Mozilla Developper Network
// https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Regular_Expressions
exports.regExp = exports.regExpPattern = str => str.replace( /([.*+?^${}()|[\]/\\])/g , '\\$1' ) ;

// This replace any single $ by a double $$
exports.regExpReplacement = str => str.replace( /\$/g , '$$$$' ) ;

// Escape for string.format()
// This replace any single % by a double %%
exports.format = str => str.replace( /%/g , '%%' ) ;

exports.jsSingleQuote = str => exports.control( str ).replace( /'/g , "\\'" ) ;
exports.jsDoubleQuote = str => exports.control( str ).replace( /"/g , '\\"' ) ;

exports.shellArg = str => '\'' + str.replace( /'/g , "'\\''" ) + '\'' ;



var escapeControlMap = {
	'\r': '\\r' ,
	'\n': '\\n' ,
	'\t': '\\t' ,
	'\x7f': '\\x7f'
} ;

// Escape \r \n \t so they become readable again, escape all ASCII control character as well, using \x syntaxe
exports.control = ( str , keepNewLineAndTab = false ) => str.replace( /[\x00-\x1f\x7f]/g , match => {
	if ( keepNewLineAndTab && ( match === '\n' || match === '\t' ) ) { return match ; }
	if ( escapeControlMap[ match ] !== undefined ) { return escapeControlMap[ match ] ; }
	var hex = match.charCodeAt( 0 ).toString( 16 ) ;
	if ( hex.length % 2 ) { hex = '0' + hex ; }
	return '\\x' + hex ;
} ) ;



var escapeHtmlMap = {
	'&': '&' ,
	'<': '&lt;' ,
	'>': '&gt;' ,
	'"': '&quot;' ,
	"'": '&#039;'
} ;

// Only escape & < > so this is suited for content outside tags
exports.html = str => str.replace( /[&<>]/g , match => escapeHtmlMap[ match ] ) ;

// Escape & < > " so this is suited for content inside a double-quoted attribute
exports.htmlAttr = str => str.replace( /[&<>"]/g , match => escapeHtmlMap[ match ] ) ;

// Escape all html special characters & < > " '
exports.htmlSpecialChars = str => str.replace( /[&<>"']/g , match => escapeHtmlMap[ match ] ) ;

// Percent-encode all control chars and codepoint greater than 255 using percent encoding
exports.unicodePercentEncode = str => str.replace( /[\x00-\x1f\u0100-\uffff\x7f%]/g , match => {
	try {
		return encodeURI( match ) ;
	}
	catch ( error ) {
		// encodeURI can throw on bad surrogate pairs, but we just strip those characters
		return '' ;
	}
} ) ;

// Encode HTTP header value
exports.httpHeaderValue = str => exports.unicodePercentEncode( str ) ;