Event Pages for WebExtensions in Firefox 106

[tay1orjones]

The Carbon Design System email address just received notice from Firefox:

Hello from the Firefox Add-ons team!

We're reaching out to inform you of changes we've made in support of Event Pages API (as part of the ongoing MV2 to MV3 migration), and these changes may impact your extension if you explicitly declared non-persistent background scripts (a.k.a. Event Pages) in the manifest.

In the past, WebExtensions in Firefox have ignored this value and treated all background scripts as persistent. Starting with 106 (currently in beta, release version shipping October 18th), Event Pages will be turned on by default for all users.

For extensions that set persistent to false prior to Firefox 106, we're unsure whether they are compatible with our new Event Page implementation. We encourage you to test your extension to ensure it will continue to work in Firefox with Event Pages turned on. Testing Event Pages offers two potential benefits: 1) You'll know if your extension remains functional with Event Pages enabled in MV2; and if so, 2) You'll know you're already prepared for the eventual migration to MV3.

To make sure your extension stays functional for your users as they update to the 106, now is the time to test it and make changes if needed.

You may also want to read more about event pages in the MV3 migration guide.

In the event your extension does not work with Event Pages enabled and you don't have the bandwidth to make updates soon, you can change the persistent value to true (please note, however, that you'll eventually need Event Pages to work when you want to migrate to MV3).

Lastly, we'd greatly appreciate any feedback you might be inclined to share regarding your experience testing Event Pages (even if you don't plan to make any changes, we'd still be interested to hear from you).

The best places to post feedback or engage us with questions are chat.mozilla.org ("Add-ons" room), or find us on Discourse (where knowledge may be shared among other developers).

Thank you in advance and we hope to hear from you soon!

Firefox Add-ons Team