Empirical studies of test case prioritization in a junit testing environment

Test case prioritization provides a way to run test cases with the highest priority earliest. Numerous empirical stud-ies have shown that prioritization can improve a test suite’s rate of fault detection, but the extent to which these results generalize is an open question because the studies have all focused on a single procedural language, C, and a few spe-cific types of test suites. In particular, Java and the JU-nit testing framework are being used extensively in prac-tice, and the effectiveness of prioritization techniques on Java systems tested under JUnit has not been investigated. We have therefore designed and performed a controlled ex-periment examining whether test case prioritization can be effective on Java programs tested under JUnit, and com-paring the results to those achieved in earlier studies. Our analyses show that test case prioritization can significantly improve the rate of fault detection of JUnit test suites, but also reveal differences with respect to previous studies that can be related to the language and testing paradigm.