If you're writing imperative code with side-effects (or mixed-style) like much classic JS code is, the existence of foo on the call stack indicates that perform

If you're writing imperative code with side-effects (or mixed-style) like much classic JS code is, the existence of foo on the call stack indicates that performSomeEffect has been run, and thus it's side-effects on our global state when we enter baz has to be accounted for. Is it an ideal style to write code in? No. Does real code have this problem, Yes!