There's a lack of test coverage over the namespace aspect of getPropertyType

[lukewarlow]

A WPT test (or subtest) should be added to test the elementNs parameter of getPropertyType

[fred-wang]

I'm going to implement getPropertyType/getAttributeType in Firefox, so I'll make sure we have enough test coverage.

[fred-wang]

Uploaded something there: https://phabricator.services.mozilla.com/D226122

[fred-wang]

I think this can be closed since that's addressed by web-platform-tests/wpt@3f6b218 and web-platform-tests/wpt@da5e743#diff-bbed4f84dea0d96f255fd583d63ad05036783ba823398da9fa38d6496f31432eR118

web-platform-tests/wpt#48769 will also check explicit null values.