一句话：提出用变化式执行完整发现高阶变异体，并据此设计高效搜索策略。
高阶变异通过组合多个变异来模拟更真实的故障并改进测试优化，但变异组合的搜索空间随阶数指数增长，现有基于遗传搜索的方法不完备且开销大。本文首先提出利用 variational execution（变化式执行）在多数情况下完整且高效地探索大型搜索空间，从而找到完整的高阶变异体集合；随后基于该完整集合分析高阶变异体的特征；最后根据这些特征设计并评估一种不依赖 variational execution 的新搜索策略。结果表明，变化式执行能有效获得完整集合，而新搜索策略即使在大规模代码库中也能高效发现高阶变异体。
Higher-order mutation has the potential for improving major drawbacks of traditional first-order mutation, such as by simulating more realistic faults or improving test-optimization techniques. Despite interest in studying promising higher-order mutants, such mutants are difficult to find due to the exponential search space of mutation combinations. State-of-the-art approaches rely on genetic search, which is often incomplete and expensive due to its stochastic nature. First, we propose a novel way of finding a complete set of higher-order mutants by using variational execution, a technique that can, in many cases, explore large search spaces completely and often efficiently. Second, we use the identified complete set of higher-order mutants to study their characteristics. Finally, we use the identified characteristics to design and evaluate a new search strategy, independent of variational execution, that is highly effective at finding higher-order mutants even in large codebases.
@inproceedings{paperbot5790,
title = {Efficiently finding higher-order mutants},
author = {Chu-Pan Wong and Jens Meinicke and Leo Chen and João P. Diniz and Christian Kästner and Eduardo Figueiredo},
booktitle = {FSE},
year = {2020},
doi = {10.1145/3368089.3409713}
}