Enhancing Software Development Techniques via Copy Codebases

Thesis (Ph.D.)--University of Washington, 2015Most software development tasks require developers to interact with multiple versions of a codebase directly or through an analysis tool. Consider a developer, Alice, who wants to implement a new feature. To ensure that her changes are of high quality, Alice might want to continuously analyze the current codebase. To make the changes fast but with confidence, Alice might use automated transformations such as refactorings. While using these transformations Alice might want to analyze the likely future codebases, which these transformations would generate, to make more informed decisions. Finally, to pinpoint the cause of any regression defect, Alice might want to analyze historical codebases e.g., binary search the development history. Unfortunately, developers' interaction with multiple codebases is limited since modern integrated development environments (IDEs) maintain one version of the codebase with limited development history. First, it is difficult to run an arbitrary analysis continuously with development since most analyses assume that the code under analysis does not change for the duration of the analysis. Second, having access to one codebase makes it impossible to analyze likely future codebases continuously with development since the modifications done to generate the future codebases conflict with development. Third, maintaining a limited development history makes it difficult to analyze historical codebases e.g., to extract information from the development history. This dissertation introduces a novel technique, Codebase Replication, which creates and incrementally maintains a copy of the developer's codebase. Our thesis is that having access to copy codebases improves developers' interaction with the current codebase, likely future codebases, and historical codebases. Improving the developer's interaction with codebases will simplify software engineering tasks and reduce developer mistakes. Continuous analyses — analyses that run in the background after each developer edit and update their result unobtrusively — improve developers' interaction with the current codebase. Having access to an in-sync copy codebase simplifies the design and implementation of continuous analyses. We introduce Codebase Analysis, which lets developers run an existing analysis continuously with development without worrying about conflicting edits. We prototyped Solstice, an implementation of Codebase Analysis for the Eclipse IDE. Solstice has negligible (