I recommend that you use one of these Firefox/Abrowser/IceCat addons.
(1) NoScript (installed by default in Tor Browser) will block JavaScript code from all webpages unless you explicitly choose to allow it on a particular page.
(2) LibreJS (installed by default in IceCat) will allow JavaScript code if it is trivial or if it can determine that it is free software. Otherwise you will have to explicitly choose to allow it on a particular page.
