TREC: A Regression Test Recommender for Java Projects

Regression testing is critical for maintaining software quality. Therefore, developers must maintain efficient and effective regression test suites. However, the task can be tedious and challenging, especially in Continuous Integration (CI) where developers frequently change code. With each code change, developers may need first to identify all relevant tests for the code change and then identify specific tests among the relevant tests that need to be modified. This process can reduce developers' productivity if they do this manually. Developers may also not modify test suites due to time constraints, resulting in inefficient and ineffective test suites. In this paper, we propose a technique and tool, TREC, that identifies relevant tests for code changes in CI and recommends tests to developers for modifications. TREC performs method and test co-evolution and method call analysis to identify and recommend tests for code changes. We evaluate the effectiveness of TREC by recommending tests for 1,699 developers' modified methods in 437 commits from three open-source Java projects. We find TREC's recommended tests include 2,886 (84.39%) of the 3,420 developers' modified tests for the 1,699 methods, indicating TREC's capability to successfully identify and recommend the majority of tests that need to be modified for the methods. Demo: https://www.youtube.com/watch?v=WgIveZuPDBU