Missing a comma in a class.
Firefox: “Everything’s cool, brosef!” :: empty screen ::
Chrome 1st time: “You can’t load local files, lol, eff you!” :: empty screen ::
Chrome 2nd time via sudo: “Uncaught SyntaxError: Unexpected token :”
Safari 1st time: “‘with’ statements aren’t allowed in strict mode”
Safari 2nd time: “SyntaxError: Expected token ‘}'”
https://www.destroyallsoftware.com/talks/wat