Coverage criteria play a central role in assessing test adequacy in classical software, yet their effectiveness for quantum programs remains poorly understood and largely unexplored. In this paper, we propose six quantum-tailored criteria - condition, decision, and path coverage, and their probabilistic variants - adapted from their classical counterparts. We present QaCoCo, a tool that computes these criteria for circuit-based quantum programs. We empirically evaluate these criteria on a large and diverse set of 540 circuits and analyze the coverage achieved. Our results show that while circuits frequently achieve high condition and decision coverage (97.56% and 97.63%, on average), path coverage remains limited (71.84%), particularly in the presence of multi-controlled gates, which induce extreme path explosion and coverage imbalance. Moreover, to account for the probabilistic nature of quantum circuits, we introduce probabilistic coverage, which augments structural coverage with a confidence measure (88.87%, 88.65%, and 37.18% for condition, decision, and path coverage, respectively, on average). Finally, through mutation testing, we find weak or no correlation between fault detection and structural coverage, consistent with observations in classical computing.

翻译：覆盖准则是评估经典软件测试充分性的核心要素，但它们在量子程序中的有效性仍未得到充分理解与探索。本文提出了六种面向量子特性的准则——条件覆盖、决策覆盖、路径覆盖及其概率变体——这些准则由经典对应准则改编而来。我们介绍了QaCoCo工具，该工具可计算基于电路的量子程序的这些准则。我们在包含540个电路的多样化大型数据集上对这些准则进行了实证评估，并分析了所实现的覆盖程度。结果表明：尽管电路通常能实现较高的条件覆盖率和决策覆盖率（平均分别为97.56%和97.63%），但路径覆盖率仍然有限（71.84%），特别是在存在多控门的情况下，多控门会引发极端的路径爆炸和覆盖不均衡。此外，为考虑量子电路的概率特性，我们引入了概率覆盖概念，该概念通过置信度度量对结构性覆盖进行增强（条件、决策和路径覆盖的平均值分别为88.87%、88.65%和37.18%）。最后，通过变异测试发现，故障检测与结构性覆盖之间相关性很弱或不相关，这一观察结果与经典计算中的结论一致。