Towards Agile Testing of Exceptional Behavior

Many of the problems found in the uses of exception handling are caused by the lack of testing and a priori design of the exceptional behavior. As a consequence, exceptions flow in unforeseen ways during the execution of a software system, causing a negative impact on reliability. This paper presents a new agile approach to test the exceptional behavior of a system. It supports developers in checking whether exceptions, at runtime, travel through the expected paths. It is agile because tests are written without the need for extra documentation. We present a preliminary evaluation of the proposed approach, where it helped us to uncover four bugs in a production system, two of them previously unknown. We have implemented the proposed approach as an extension of the JUnit framework.