An empirical analysis of a testability model for object-oriented programs

Abstract

We present, in this paper, a metric based testability model for object-oriented programs. The model is, in fact, an adaptation of a model pro-posed in literature for assessing the testability of object-oriented design. The study presented in this paper aims at exploring empirically the capa-bility of the model to assess testability of classes at the code level. We investigate testability from the perspective of unit testing and required testing effort. We designed an empirical study using data collected from two Java software systems for which JUnit test cases exist. To capture testability of classes in terms of required testing effort, we used different metrics to quantify the corresponding JUnit test cases. In order to eva-luate the capability of the model to predict testability of classes (charac-teristics of corresponding test classes), we used statistical tests using correlation.