How do I clear the JavaScript file cache in Firefox on every visit in a page?

"I don't think there is a built-in way to stop caching of just javascript within Firefox, but you can stop Firefox from using cached files altogether , which will have the same desired effect for developing. Navigate to about:config in the address bar and filter to network.http.use-cache. Set it to false to stop Firefox from using cached files.

You can do the same with the Web Developer Toolbar:"