Context:

In integration testing, the order in which classes are integrated and tested is significant for the construction of test stubs. With the existing approaches, it is usually difficult to generate the sub-optimal test orders for real applications, which have large numbers of classes.

Objective:

There exist moderately large numbers of classes in software systems, which is one of the main factors that complicate the generation of class integration test order (CITO). The main objectives of this study are reducing the problem space for CITO generation, and minimizing the stubbing cost of the generated test orders.

Method:

The approach proposed in this study is based on the hypothesis that similar-class combination can remove class dependencies and yield a smaller problem space. Identical class dependence and symmetric classes are the two main properties that are used to identify similar classes. In addition, a new cycle-breaking algorithm is introduced to minimize the stubbing cost of the generated test orders, which fully considers the two factors (number of test stubs and the corresponding stubbing complexity) that affect the overall stubbing cost. Empirical experiments are conducted on nine open-source Java programs to evaluate the performance of the proposed approach.

Results:

With similar-class combination, the proposed approach reduced the numbers of classes and class dependencies by over 10% and 6%, respectively, for six programs. Moreover, for four programs, the proposed approach reduced the number of cycles among class dependencies by more than 20%. The cycle-breaking algorithm achieved reduction of more than 13% in the stubbing cost, thus outperforming other competing techniques.

Conclusions:

The proposed method relies on the two aforementioned important properties to identify similar classes, and these properties are known to significantly improve the performance of CITO generation. The results obtained in this study confirmed the capability of the proposed approach in terms of minimizing the number of classes and class dependencies in programs. It outperformed other competing methods in minimizing the stubbing costs of the generated test orders.

中文翻译：

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评估相似类组合对类集成测试订单生成的影响

内容：

在集成测试中，类的集成和测试顺序对于构建测试存根至关重要。使用现有方法，通常很难为具有大量类的实际应用生成次优测试订单。

目的：

软件系统中存在适量的类，这是使类集成测试订单（CITO）生成复杂化的主要因素之一。这项研究的主要目的是减少生成CITO的问题空间，并最大程度地减少生成的测试订单的存根成本。

方法：

本研究中提出的方法基于以下假设：相似类组合可以消除类依赖关系，并产生较小的问题空间。相同的类依赖性和对称的类是用于标识相似类的两个主要属性。另外，引入了一种新的循环中断算法以最小化所生成测试订单的存根成本，该算法充分考虑了影响总存根成本的两个因素（测试存根的数量和相应的存根复杂度）。在9个开源Java程序上进行了实验，以评估所提出方法的性能。

结果：

通过类似的类组合，对于六个程序，所提出的方法分别将类和类相关性的数量减少了10％和6％以上。此外，对于四个程序，所提出的方法将类依赖之间的循环数减少了20％以上。打破循环的算法使存根成本降低了13％以上，从而胜过其他竞争技术。

结论：

所提出的方法依靠上述两个重要属性来识别相似的类别，并且已知这些属性可以显着提高CITO生成的性能。在这项研究中获得的结果证实了该方法在最小化程序中的类数和类依赖性方面的能力。在最小化生成的测试订单的存根成本方面，它优于其他竞争方法。