A Framework for Checking Regression Test Selection Tools

Regression test selection (RTS) reduces regression testing costs by re-running only tests that can change behavior due to code changes. Researchers and large software organizations recently developed and adopted several RTS tools to deal with the rapidly growing costs of regression testing. As RTS tools gain adoption, it becomes critical to check that they are correct and efficient. Unfortunately, checking RTS tools currently relies solely on limited tests that RTS tool developers manually write. We present RTSCheck, the first framework for checking RTS tools. RTSCheck feeds evolving programs (i.e., sequences of program revisions) to an RTS tool and checks the output against rules inspired by existing RTS test suites. Violations of these rules are likely due to deviations from expected RTS tool behavior, and indicative of bugs in the tool. RTSCheck uses three components to obtain evolving programs: (1) AutoEP automatically generates evolving programs and corresponding tests, (2) DefectsEP uses buggy and fixed program revisions from bug databases, and (3) EvoEP uses sequences of program revisions from actual open-source projects' histories. We used RTSCheck to check three recently developed RTS tools for Java: Clover, Ekstazi, and STARTS. RTSCheck discovered 27 bugs in these three tools.