Feature-oriented Test Case Selection and Prioritization During the Evolution of Highly-Configurable Systems

TL;DR

FeaTestSelPrio addresses regression testing for Highly Configurable Systems by statically mapping test cases to feature implementations via pre-processor directives and performing feature-aware test selection followed by prioritization. The method extends FeaTestSel with a prioritization step that ranks tests by the number of features they cover, enabling earlier fault detection while maintaining comprehensive failure coverage. Empirical evaluation on Libssh and Libsoup shows that FeaTestSel reduces test execution time by about 50% relative to retest-all, and FeaTestSelPrio further reduces the average budget for detecting failures, achieving lower budgets in up to 86% of failed commits. The approach yields actionable traceability outputs, requires no failure-history, and is practical for CI-driven evolution of HCSs, with future work to broaden system coverage and explore additional prioritization strategies.

Abstract

Testing Highly Configurable Systems (HCSs) is a challenging task, especially in an evolution scenario where features are added, changed, or removed, which hampers test case selection and prioritization. Existing work is usually based on the variability model, which is not always available or updated. Yet, the few existing approaches rely on links between test cases and changed files (or lines of code), not considering how features are implemented, usually spread over several and unchanged files. To overcome these limitations, we introduce FeaTestSelPrio, a feature-oriented test case selection and prioritization approach for HCSs. The approach links test cases to feature implementations, using HCS pre-processor directives, to select test cases based on features affected by changes in each commit. After, the test cases are prioritized according to the number of features they cover. Our approach selects a greater number of tests and takes longer to execute than a changed-file-oriented approach, used as baseline, but FeaTestSelPrio performs better regarding detected failures. By adding the approach execution time to the execution time of the selected test cases, we reached a reduction of $\approx$50%, in comparison with retest-all. The prioritization step allows reducing the average test budget in 86% of the failed commits.

Figures (13)

• Figure 1: Number of modifications made in commit c64ec43
• Figure 2: Example of modification in commit c64ec43
• Figure 3: Overview of our approach
• Figure 4: Configuration file used as input
• Figure 5: Conditional blocks of feature implementations.