Escape all characters in a string using both Unicode and hexadecimal escape sequences

unicodeEscape.js

// Ever needed to escape '\n' as '\\n'? This function does that for any character,
// using hex and/or Unicode escape sequences (whichever are shortest).
// Demo: http://mothereff.in/js-escapes
function unicodeEscape(str) {
	return str.replace(/[\s\S]/g, function(character) {
		var escape = character.charCodeAt().toString(16),
		    longhand = escape.length > 2;
		return '\\' + (longhand ? 'u' : 'x') + ('0000' + escape).slice(longhand ? -4 : -2);
	});
}

Check out jsesc which solves this problem in a more robust manner.

@mathiasbynens It looks great! I did try to use it but unfortunately I'm not up to date with all the browserify/bundling stuff and just need a vanilla JS script (e.g. no use of Buffer) to include in a module import and wasn't able to work out how to do that with jsesc (though I admit I only poked around for a few minutes before deciding to write the function above). Also, out of pure curiosity I'd be interested in cases where the above function fails - I couldn't find any failing cases in my tests.

@josephrocca See https://github.com/mathiasbynens/jsesc#support. TL:DR use v1.3.0.