MobileFrontend's PHP code coverage is currently very low (at time of writing this ticket, it is 27% (and low!)
See:
https://doc.wikimedia.org/cover-extensions/MobileFrontend/
We would like to improve things here, with a target of at least 50% as a starting point.
Suggested focus errors
- Remove redundant code
- write tests for the Amc folder
- write tests for MobileFrontendHooks.php