If we're going to store JavaScript gadgets and Lua modules in a central wiki (this is planned, I suppose), some coding guidelines would be certainly useful. Should a Request for Comment be created for that? We can reuse MediaWiki conventions for JavaScript, of course.
Moreover, I find that there should be a way to run linters automatically over JavaScript gadgets and Lua modules. Even though CodeEditor already has this feature, it would be helpful to have a service (on Labs?) that periodically analyzes scripts on a wiki and reports errors, maybe notifying the author of a breakage via e-mail. Here are some already existing tools for similar purposes: https://tools.wmflabs.org/stylize/ http://lintbridge.wmflabs.org