Do you treat JavaScript like a real language?

JavaScript is a real language and should be treated like one!

Would you put all your C# code in one file? Would you write single modules with every method your application could need? Of course not! It's important to maintain coding standards when writing JavaScript just as you would when writing C#. Where appropriate, try to follow the Rules to Better Architecture and Code Review with your JavaScript as well. In particular, make sure you're still following the SOLID principles as much as you can.