A simple breakpoint in your JS exposes the salt value. It is not accessible to code outside the IIFE (Immediately Invoked Function Expression - what you are calling anonymous function), but if you're trying to keep a debugger from seeing it via a breakpoint inside the IIFE, then JS is not going to prevent that in any way.
For example, you can set a breakpoint right where the salt value is coined and see what it is or if that code is dynamically loaded via ajax, you can set a breakpoint on the ajax loading code and then step through the loading of the code until you can then set a breakpoint where the sale value is coined.