Test confessions: A study of testing practices for plug-in systems

Testing plug-in-based systems is challenging due to complex interactions among many different plug-ins, and variations in version and configuration. The objective of this paper is to increase our understanding of what testers and developers think and do when it comes to testing plug-in-based systems. To that end, we conduct a qualitative (grounded theory) study, in which we interview 25 senior practitioners about how they test plug-in applications based on the Eclipse plug-in architecture. The outcome is an overview of the testing practices currently used, a set of identified barriers limiting test adoption, and an explanation of how limited testing is compensated by self-hosting of projects and by involving the community. These results are supported by a structured survey of more than 150 professionals. The study reveals that unit testing plays a key role, whereas plug-in specific integration problems are identified and resolved by the community. Based on our findings, we propose a series of recommendations and areas for future research.