Javascript – How to cleanup unreferenced Javascript libraries


Our project has more than 300 JSP files and more than 200 JavaScript files. I'd like to do some cleanup, removing unnecessary JS files. Even if the JSP includes the JS maybe none of the functions are used. The goal is to reduce both complexity and time needed to load the page. My IDE is Eclipse. Giving the dynamic nature of JavaScript I guess it will be hard or even impossible.

Best Solution

If it's conceivable that the application can be tested with a lot of coverage (i.e. going through every dialog, error message, and situation imaginable) you may be able to work with your access log files - compare the list of JS files to those fetched after period x of heavy use.

An alternative implementation of this would be setting up a "honeypot" (see my answer to this question).

Both these methods are of course "soft" in that their quality relies in how throroughly the application is actually used during testing time.

If you have any way of grepping all script references, that would be preferable. Maybe you can do a global search on {anything}.js, that would match most ways how to embed a JS file.