Is firefox-mv2 build supposed to work from a mv3 extension?

[heartgg]

I built an extension using Manifest V3 and compiled it to chrome which works fine. However, I compiled it to Firefox as well using firefox-mv2 and the extension throws lots of errors and does not work. I'm suspecting this is because the extension build is not compatible with going from MV3 to MV2 because the errors that are thrown are mostly upset about the chrome object not existing.

Is there a work around or is this a question of time when we'll get firefox-mv3 build support?

[louisgv]

Can you post the error you're seeing? - the chrome object is actually available in firefox for compatibility, but for some API it's not available and you might need to use something like webextpolyfill: https://github.com/mozilla/webextension-polyfill

I don't really like that package since it throws top-level error at import, making it not suitable to write reusable code for all runtime such as sandbox pages or mainworld

On the other hand - try out the firefox-mv3 target and see if it works ;d...

Also I'm curious - which chrome API is firefox complaining about?

[heartgg]

firefox-mv3 worked, I just had no idea that it would since it's not documented anywhere. That fixed all of my issues.

[louisgv]

The mv3 scheme on firefox is a bit weird - it uses background page still. We added it not too long ago to experiment around with. If you found any issue feel free to file them, and if it works well - feel free to PR the docs that firefox-mv3 works :p