Problems of test-driven aspect-oriented development

Abstract

Problems of test-driven aspect-oriented development Test-driven development and aspect-oriented programming are relatively new development techniques each having its own benefits. However, using aspect-oriented language like AspectJ in test-driven development leads to new types of problems that do not appear if these two approaches are applied separately. These problems arise mainly because aspect-oriented paradigm breaks encapsulation principle - behaviour of class is not implemented just in class itself like in traditional object-oriented programming but can be heavily affected by many external aspects. Traditional unit tests designed to test a single unit are not sufficient any more because behaviour being tested is distributed through several units at once, so test design becomes more complicated. In order to efficiently use these two techniques together such problems have to be identified and ways to workaround them have to be discovered. This paper focuses on those problems, describing the most notable ones. Problem descriptions are based on experience with AspectJ, but most of them are common to any aspect-oriented language with similar features. Some empirically discovered principles are provided that help softening negative impact of those problems.