Your post is a hot mess.
So, you want Javascript to be secure, but not allow the user downloading it to be able to see what they are running? Do you even understand how Javascript works in a browser beyond "hitting F12?" For the love of WTF, they are not "seeing the Javascript on your site", you are letting them DOWNLOAD the Javascript to their computer and then run it.
How, precisely, do you expect an interpreted text file to be hidden from a web browser that downloads and executes an interpreted text file? And more importantly, WHY would a browser want to let you do that, unless to obscure what you are trying to run on a user's computer?!?
The sum total of Javascript exploits is a browser that allows Javascript exploits. If they were implemented correctly there would be no problem.