Is AOP code easier or harder to test than OOP code?

The adoption of traditional testing techniques with AOP systems is expected to be quite hard, because of the novel constructs offered by AOP. For example, testing should validate the pointcut designators, which define the execution points at which aspects apply. These may be difficult to test when they involve complex dynamic conditions. depending on the execution stack. Other sources of difficulties are associated with the aspect composition order, with the intertype declarations, and with the changes in normal and exceptional control flow; possibly introduced by aspects. On the other hand, a novel, aspect oriented approach to testing could be devised, which takes advantage of the separation of concerns implemented in AOP code, in order to extend the benefits of such separation to the testing phase. In this paper, an incremental testing process is considered, which allows testing the base code and the cross-cutting functionalities, implemented as aspects, in separate, successive steps