edit: I misread the question, my comment was geared toward languages transpiled to JS. It's compile-time safety. Virtually none of the type knowledge exists i

edit: I misread the question, my comment was geared toward languages transpiled to JS. It's compile-time safety. Virtually none of the type knowledge exists in the runtime. Still, it's far better than nothing, with the self-documenting nature of typed code being one of the biggest wins IMO.