A study of refactorings during software change tasks

Developers frequently undertake software change tasks that could be partially or fully automated by refactoring tools. As has been reported by others, all too often, these refactoring steps are instead performed manually by developers. These missed opportunities are referred to as occasions of disuse of refactoring tools. We perform an observational study in which 17 developers with professional experience attempt to solve three change tasks with steps amenable to the use of refactoring tools. We found that the strategies developers use to approach these tasks shape their workflow, which, in turn, shape the opportunities for refactoring tool use. We report on a number of findings about developer strategies, demonstrating the difficulty of aligning the kind of refactoring steps that emerge during a change task based on the strategy with the tools available. We also report on findings about refactoring tools, such as the difficulties developers face in controlling the scope of application of the tools. Our findings can help inform the designers of refactoring tools.