This paper proposes a new testing technique for component composition of EJBs. We define components made by a current developer as white box components and components made by another developer as black box components. Software from CBSD consists of black box components and white box components, and composition errors result from the interaction between black box component and white box components, or the interaction between two white box components. Our technique tests these composition errors.

We select test cases by injecting a fault into a specific parts of the white box component. The specific parts we define in this paper leads to the high effectiveness of our technique. We evaluate this effectiveness through an experiment and a theorem. In addition, we provide an example in Enterprise JavaBeans in this paper.