一句话：提出 μAkka，基于真实 Akka 缺陷设计变异算子，用于评估 Actor 并发测试有效性。
论文针对 Actor 并发缺乏基于真实缺陷的变异测试问题，提出 μAkka。作者首先人工分析 Stack Overflow 与 GitHub 上 186 个真实 Akka 缺陷的成因，据此设计 32 个变异算子（含 138 处 Akka API 源码变更），并在 Eclipse 插件中实现，面向 Java Akka。评估中，插件为 10 个真实 GitHub 应用（44.64 万行代码、7.9k 测试）生成 1.17 万变异体；运行测试衡量变异体质量与测试有效性；再用 PIT 生成 2.62 万变异体进行对比，并人工分析缺陷覆盖与重叠。结果表明 μAkka 变异体质量更高、覆盖更多真实缺陷，且现有测试更难检测。
Actor concurrency is becoming increasingly important in the real world and mission-critical software. This requires these applications to be free from actor bugs, that occur in the real world, and have tests that are effective in finding these bugs. Mutation testing is a well-established technique that transforms an application to induce its likely bugs and evaluate the effectiveness of its tests in finding these bugs. Mutation testing is available for a broad spectrum of applications and their bugs, ranging from web to mobile to machine learning, and is used at scale in companies like Google and Facebook. However, there still is no mutation testing for actor concurrency that uses real-world actor bugs. In this paper, we propose 𝜇Akka, a framework for mutation testing of Akka actor concurrency using real actor bugs. Akka is a popular industrial-strength implementation of actor concurrency. To design, implement, and evaluate 𝜇Akka, we take the following major steps: (1) manually analyze a recent set of 186 real Akka bugs from Stack Overflow and GitHub to understand their causes; (2) design a set of 32 mutation operators, with 138 source code changes in Akka API, to emulate these causes and induce their bugs; (3) implement these operators in an Eclipse plugin for Java Akka; (4) use the plugin to generate 11.7k mutants of 10 real GitHub applications, with 446.4k lines of code and 7.9k tests; (5) run these tests on these mutants to measure the quality of mutants and effectiveness of tests; (6) use PIT to generate 26.2k mutants to compare 𝜇Akka and PIT mutant quality and test effectiveness. PIT is a popular mutation testing tool with traditional operators; (7) manually analyze the bug coverage and overlap of 𝜇Akka, PIT, and actor operators in a previous work; and (8) discuss a few implications of our findings. Among others, we find that 𝜇Akka mutants are higher quality, cover more bugs, and tests are less effective in detecting them.
@inproceedings{paperbot7689,
title = {𝜇Akka: Mutation Testing for Actor Concurrency in Akka using Real-World Bugs},
author = {Mohsen Moradi Moghadam and Mehdi Bagherzadeh and Raffi Khatchadourian and Hamid Bagheri},
booktitle = {FSE},
year = {2023},
doi = {10.1145/3611643.3616362}
}