I agree. If behaviors A, B, and C are provided by the superclass, then A, B, and C should be tested in the super-test. My subclass provides behavior D, thus I provide tests for behavior D, inheriting the tests for behaviors A, B, and C. If the superclass changes its behavior, it will change its tests. My testing of my subclass will inherit the changes in the tests. No problem.
We are the carpenters and bricklayers of the Information Age.
The idea is a little like C++ templates, except not quite so brain-meltingly complicated. -- TheDamian, Exegesis 6
Please remember that I'm crufty and crochety. All opinions are purely mine and all code is untested, unless otherwise specified.