Rudder

The code to do it is in builder/js/ncf.js in function getClassKind

param = param.replace(/\\'/g, "'").replace(/\\"/g, '"').replace(/[^\${}\w](?![^{}]+})|\$(?!{)/g,"_");

The regex is a negative one that trie to replace any invalid character that is not part of a variable.

I suggest to replace this with a positive regex that replaces everything valid (which can be longer that a char) by itself and everything else by a '_'.
The replace becomes (perl syntax) :

(  variable | valid_char or nothing ) then invalid_char -> 'valid_part' then '_'
s/(\$\{[\w\[\]\${}]+\}|\w*)[^\w]/$1_/g

Fixed by  #11600