KEY_FIREFOX_ANDROID_UNSUPPORTED_BY_MIN_VERSION warning though gecko_android is not set

[airtower-luna]

I'm getting the following error running web-ext lint:

Validation Summary:

errors          0              
notices         0              
warnings        1              

WARNINGS:

Code                                  Message       Description              F
KEY_FIREFOX_ANDROID_UNSUPPORTED_BY…   Manifest      "strict_min_version"     m
_MIN_VERSION                          key not       requires Firefox for     s
                                      supported     Android 140, which was    
                                      by the        released before           
                                      specified     version 142 introduced    
                                      minimum       support for               
                                      Firefox for   "browser_specific_set…    
                                      Android       tings.gecko.data_coll…    
                                      version       ection_permissions".      

However, my manifest.json does not define browser_specific_settings.gecko_android at all, see:
https://github.com/airtower-luna/referer-mod/blob/da60b5202e4d2f6ab8037a73d274ece6b664653f/manifest.json#L38-L46

The Extension Workshop site recommends:

Due to Android's different APIs and form factors (compared to desktop Firefox), set gecko_android after explicitly verifying compatibility.

Right now it seems to me that the only way to get rid of this warning would be to declare compatibility, regardless of having tested. Seems like a bug to me.

[willdurand]

Hi. What the linter tells you is essentially that data collection permissions are available on Firefox for Android 142 and above. When you set a strict min version in gecko, it applies to both Firefox for desktop and Firefox for Android by default (unless you override the strict min version in gecko_android). Since you don't have such key, the linter (correctly) assumes that this add-on is compatible with Gecko 140 and above, which applies to both Firefox for desktop and Firefox for Android.

While the presence of the gecko_android key in the manifest file explicitly indicates that the extension is compatible with both Firefox for desktop and Firefox for Android, its absence is not an indication that the extension isn't compatible with Firefox for Android (because DevHub lets you do that in the web UI too). That's why the linter assumes the extension is compatible with Firefox for Android (in addition to desktop).

Since the data collection permissions have been implemented first for desktop (Fx140) and later for Android (Fx142), the linter warns you that, if the extension happens to be compatible with Android, then the strict min version is too low.

With that said, it took me some time to figure that out, and I implemented the entire data collection stuff, so I think there is a lot of room for improvement here. I am not entirely sure what to do next, though. The linter is technically accurate but the description isn't clear. Maybe we could add a note on extensionworkshop.com?

[airtower-luna]

That makes sense, so essentially the issue is in the manifest definition, not the linter, and there's no way to indicate "not supported". 😅

Though what I really want is to just make no statement on Android compatibility, in the classic open source "you're welcome to try, but you're on your own" way. I guess with the current manifest definition adding gecko_android is the closest I can get. Thanks!

[Rob--W]

@willdurand to avoid confusion for this common case, WDYT of special casing the situation, to not warn about 140/141 for Android? Firefox users on Android should be relatively up to date (there is no ESR140 on Android), and users typically do not install older versions since the Play Store serves the last version.

[insin]

I was just about to create an issue for this. After updating web-ext, linting gave me this warning:

Defining browser_specific_settings.gecko.data_collection_permissions resulted in 2 new warnings instead:

My extensions have "strict_min_version": "121.0" as they depend on CSS :has() support - if older versions of Firefox will ignore the unknown data_collection_permissions property, should it really be a warning when you have a lower strict_min_version defined which accurately reflects required browser feature support?

If I'm eventually going to have to add this, as per https://extensionworkshop.com/documentation/develop/firefox-builtin-data-consent/, I'd rather not have false positive warnings forevermore.