During development I have to "clear cache" in Firefox all the time in order to make it use the latest version of JavaScript files.
Is there some kind of setting (about:config) to turn off caching completely for JavaScript files? Or, if not, for all files?
Enter "about:config" into the Firefox address bar and set:
browser.cache.disk.enable = false
browser.cache.memory.enable = false
If developing locally, or using HTML5's new manifest attribute you may have to also set the following in about:config -
browser.cache.offline.enable = false
The Web Developer Toolbar has an option to disable caching which makes it very easy to turn it on and off when you need it.
Firefox 48 Developer Tools
Allows you to turn off cache only when toolbox is open, which is perfect for web development:
https://stackoverflow.com/a/27397425/895245 has similar content, but positioning changed a bit since.
If you're working with server side code you could generate a random number and append it to the end of the src in the following manner....
src="yourJavascriptFile.js?randomNumber=434534"
with the randomNumber being randomly generated each time.
You can use CTRL-F5 to reload bypassing the cache.
You can set the preferences in firefox not to use the cache
network.http.use-cache = false
You can setup you web server to send a no-cache/Expires/Cache-Control headers for the js files.
Here is an example for apache web server.
Best strategy is to design your site to build a unique URL to your JS files, that gets reset every time there is a change. That way it caches when there has been no change, but imediately reloads when any change occurs.
You'd need to adjust for your specific environment tools, but if you are using PHP/Apache, here's a great solution for both you, and the end-users.
http://verens.com/archives/2008/04/09/javascript-cache-problem-solved/
I use CTRL-SHIFT-DELETE which activates the privacy feature, allowing you to clear your cache, reset cookies, etc, all at once. You can even configure it so that it just DOES it, instead of popping up a dialog box asking you to confirm.