Efficient object-oriented integration and regression testing

This paper presents a model, a strategy and a methodology for planning integration and regression testing from an object-oriented model. It shows how to produce a model of structural system test dependencies which evolves with the refinement process of the object-oriented design. The model (test dependency graph) serves as a basis for ordering classes and methods to be tested for regression and integration purposes (minimization of test stubs). The mapping from unified modeling language to the defined model is detailed as well as the test methodology. While the complexity of optimal stub minimization is exponential with the size of the model, an algorithm is given that: computes a strategy for integration testing with a quadratic complexity in the worst case; and provides an efficient testing order for minimizing the number of stubs. Various integration strategies are compared with the optimized algorithm (a real-world case study illustrates this comparison). The results of the experiment seem to give nearly optimal stubs with a low cost despite the exponential complexity of getting optimal stubs. As being a part of a design-for-testability approach, the presented methodology also leads to the early repartition of testing resources during system integration for reducing integration duration