We can improve the quality of our .js files by using JSHint to check for some common best practices.
Recently I've added grunt.js in the root folder of the project. It can be used to run JSHint and QUnit tests on the command line after making changes to any of the .js files. For now it process only wicket-event-jquery.js, wicket-ajax-jquery.js and wicket-ajax-debug-jquery.js. We should add all .js files from all modules.