Firefox 46 will be released on April
19th 26th. Here’s the list of changes that went into this version that can affect add-on compatibility. There is more information available in Firefox 46 for Developers, so you should also give it a look.
mTabFiltersproperties should be Maps rather than arrays. These are private properties, so they should be avoided in general. Note that they were also renamed to
- Hide window.showModalDialog, at least when e10s is enabled. In previous versions, using this API with e10s enabled would throw an exception. Now it isn’t present at all, so it plays better with feature detection.
- Remove legacy array/generator comprehension. Array comprehensions and generator comprehensions are non-standard. Comment 42 in the bug has some hints as to what to do instead.
- Firefox is currently enforcing add-on signing, with a preference to override it. Firefox 46 will remove the preference entirely , which means your add-on will need to be signed in order to run in release versions of Firefox. You can read about your options here.
Let me know in the comments if there’s anything missing or incorrect on these lists. If your add-on breaks on Firefox 46, I’d like to know.
The automatic compatibility validation and upgrade for add-ons on AMO will happen in a few weeks (the one for Firefox 45 is still pending), so keep an eye on your email if you have an add-on listed on our site with its compatibility set to Firefox 45.