858462 - Extension javascript cached -> issue for extension devs

Status: RESOLVED INVALID

(Firefox :: Untriaged, defect)

Description

[Mark Straver]

Not sure what component this belongs under, so marking untriaged. Help appreciated.

I'm doing extension development, and ran into a rather serious problem that had me stumped for a while: Working on extension javascript, by using distribution/bundles to be able to work "live" on the extension in the browser, I ran into the problem that Javascript would be cached somewhere. I could make changes to the JS in the extension, but it would not be picked up. This resulted in errors in the error console, pointing to lines in the JS that I had since then changed, and showed up properly. 

E.g. I could comment out a faulty line of code, and the extension would continue to give an error on the faulty line even if the .js had changed, and the error console pointing me to the commented out line.

The only way for me to have it pick up changes was to completely clear anything profile related, which, as you can imagine, makes it very difficult to edit&test extensions. Disabling/clearing disk cache did nothing.

I assume the extension js is cached *somewhere* for performance reasons, but this should include a test to see if the file that is cached has changed, or at the very least an easy way for developers to temporarily switch off this caching.

Comment 1

[Dave Garrett]

http://kb.mozillazine.org/Nglayout.debug.disable_xul_cache
http://kb.mozillazine.org/Nglayout.debug.disable_xul_fastload

I set these two prefs to true in my dev profiles to avoid problems like this. Not sure specifically what areas are affected by these prefs though.

Comment 2

[Drew Willcoxon :adw]

See also the -purgecaches command-line flag here: https://developer.mozilla.org/en-US/docs/Setting_up_extension_development_environment

Without -purgecaches, this is the expected behavior (unfortunate as it may be for people not aware of caching).