I brought assertWcssNearlyEqualOverBBox in line with
RFC-28, though only the assertion, not the predicate because it is too different. The assertion function tests all points and reports the largest difference (on sky and in pixels) if there is an error. A predicate should fail as soon as an error is detected.
I also implemented assertions for Angle, Box2, pairs (e.g. Point and Extent) and Coord. Again, I did not implement predicates because I am not convinced they are useful and it is clumsy to try to make them work as predicates and assertions (as K-T suggested in
RFC-28). I am pretty sure that a function that reports the measured difference would be more useful, but in many cases that is already implemented in some other way (e.g. Coord.angularSeparation). I felt it best to wait for a good use case before adding anything beyond the assertions.
The assertion functions and a unit test for them are in afw on tickets/
In addition, I modified two unit tests in meas_astrom on tickets/
DM-2193 to use assertWcssNearlyEqualOverBBox