A Comparative Study of Vectorization-Based Static Test Case Prioritization Methods

摘要

To enhance the efficiency of software testing, researchers have studied various test case prioritization (TCP) methods. A topic model-based TCP is one of the promising methods, which expresses test cases by topic vectors and prioritizes them in the order such that the set of already-prioritized test cases have the maximum dispersion in the vector space. However, the topic model is not the only option available for vectorizing test cases. Moreover, the distance metric in the vector space and the scheme to prioritize test cases (the way to find the test case that is the farthest from the set of already-prioritized ones) also have some available options. Because the combinations of the above options have not been well-discussed in the past, this paper conducts a comparative study of 36 TCP methods, which are the combinations of (1) three vectorization methods, (2) three distance metrics, and (3) four prioritization schemes (36=3x3x4). The empirical results show the following findings. The choice of the vectorization method has a significant impact on the testing efficiency: a promising option is Doc2Vec (PVDBoW). The combination with the distance metric may also be impactful: a useful combination is Doc2Vec (PV-DBoW) and Euclidean distance. The third aspect, i.e., the choice of the scheme to find the farthest test case, is not always influential.