A Class Library for the Automization of Class Testing

The basic unit of testing object-oriented software is the class Bin94b, MK94]. Hence class testing corresponds in object-oriented software development to unit testing in the traditional, procedural development approach. As a rule, class testing is performed by the programmer of a class by himself and not by a seperate testing group, to decrease the need for coordination MK94]. But in these situation successful testing is strongly embarrassed by psychological restraints: ' It is rather like a potter being asked to demonstrate the strenght of his or her pots by dropping them on the oor. ' Rop94] Here the automization of testing activities could increase the productivity, not just in a sence of a bigger quantitiy of executable test cases, but also in raising the quality of class testing by circumventing these psycholocical restraints. There is a great agreement between researchers , that automication is crucial for successful testing Jac92, Bin94a, MK94]. But it is also obvious that the knowledge and creativity of experienced testing personal should not hindered by innexible tools. This yields exibility as an important design goal of the library: 1. Automatic features shall be widely control-lable through parametrization. 2. The extension of new features and the cus-tomization of implementet features shall be simple. The invariant, and therefore in many testing techniques used, elements of object-oriented class testing are represented as base classes in the library: MethodEvaluator: Is an abstract class, which provides the protocol for executing and evaluating a message to the class under test (like object creation) or to an object of that class, created by a message execution from its class under test. Since evaluation already has to be prepared before the execution of the message , both properties can just be deened by subclasses like PrintrepEvaluator or AssertionEvaluator. Represents test cases as a sequence of evaluators to the class under test followed by a sequence of evaluators to an object of the class under test, which is created as a result of the execution of the primary message sequence. Regressor: Implements methods for storing, retrieving and repeated execution of once entered test cases. Regression testing can be seen as a sine qua non Bin94b], especially in the context of inheritance. Also since the degree of automication during creation of test cases should be widely adjustable, the support of regression testing becomes the more important , the less automatization is used. Hence the base classes …