The new field feature added at least 3 methods to JFormField and maybe there are even more. Neither of those methods has unittests. We should actually have unittests for both the methods in /libraries and the fields plugin, since these interact with third party code, similar to the finder code. But I could live without covering the plugins code. The methods in /libraries are a must however.

This is part of a code review of the fields feature. See #13222, #13223, #13224, #13225 and other connected issues.