This whole argument is about whether a language's built in string support should use UTF-8. There is no way that you could build a JavaScript engine where you'd even notice the additional complexity of UTF-8 compared to everything else you have to get right (and yes I've had to handle UTF-8 decoding directly before).
Plus I'm pretty sure all the major JavaScript engines (V8 for sure) already know how to handle UTF-8 since that's the encoding most scripts come from.
Plus I'm pretty sure all the major JavaScript engines (V8 for sure) already know how to handle UTF-8 since that's the encoding most scripts come from.