Test case prioritization incorporating ordered sequence of program elements

Test suites often grow very large over many releases, such that it is impractical to re-execute all test cases within limited resources. Test case prioritization, which rearranges test cases, is a key technique to improve regression testing. Code coverage information has been widely used in test case prioritization. However, other important information, such as the ordered sequence of program elements measured by execution frequencies, was ignored by previous studies. It raises a risk to lose detections of difficult-to-find bugs. Therefore, this paper improves the similarity-based test case prioritization using the ordered sequence of program elements measured by execution counts. The empirical results show that our new technique can increase the rate of fault detection more significantly than the coverage-based ART technique. Moreover, our technique can detect bugs in loops more quickly and be more cost-benefits than the traditional ones.