A class in javascript is just a variable, after all.
I think, personally, I'd've called the initial class ScoreGuts or something, or gone with a different syntax that returned the class as a value, but ... eh. It's really not that big a deal.
> I think, personally, I'd've called the initial class ScoreGuts or something
Well, maybe the point is that the original class becomes "useless" once it has been "decorated"; so it doesn't make sense that it has its own name. But it's is also true that, once you get used to program using FP style, mutating variables like this feels "weird".
Score = do_the_decoration((function () {
class Score ... {
...
}
return Score;
)());
Lol!