I am following the Mir devs and AFAICS they aim for extremely high code quality. They have a Jenkins Continous Integration Server with lots of compilers and static code analysis, they discuss coding style/quality issues on the mailing list and there are unit tests for most of the Mir codebase.
Does anybody know how the Wayland/Weston developers are handling this? I saw some unit tests in the Wayland git repository but I don't follow Wayland development.
Wayland have near to none test coverage. Which is one of the big reasons Canonical didn't choose Wayland.
Waylands developers man focus is the API, how it should look and be usable for a long period of time.