@piggo @domi @iacore ⚠ Warning: I somehow bork my browser web process while doing this one, ended up in an infinite loop.
btw for some reason unknown to myself being a JS-noob, you need to use function() {} and not () => {}.
$ node > String.prototype.toString = function() { if(this == "meow") { return ":3"; } else { throw "tangled yarn"; } }; [Function (anonymous)] > "meow".toString() ':3'