Biblio

Continuous Integration (CI) services, which can automatically build, test, and deploy software projects, are an invaluable asset in distributed teams, increasing productivity and helping to maintain code quality. Prior work has shown that CI pipelines can be sophisticated, and choosing and configuring a CI system involves tradeoffs. As CI technology matures, new CI tool offerings arise to meet the distinct wants and needs of software teams, as they negotiate a path through these tradeoffs, depending on their context. In this paper, we begin to uncover these nuances, and tell the story of open-source projects falling out of love with Travis, the earliest and most popular cloud-based CI system. Using logistic regression, we quantify the effects that open-source community factors and project technical factors have on the rate of Travis abandonment. We find that increased build complexity reduces the chances of abandonment, that larger projects abandon at higher rates, and that a project's dominant language has significant but varying effects. Finally, we find the surprising result that metrics of configuration attempts and knowledge dispersion in the project do not affect the rate of abandonment.

Learning and remembering how to use APIs is difficult. While code-completion tools can recommend API methods, browsing a long list of API method names and their documentation is tedious. Moreover, users can easily be overwhelmed with too much information. We present a novel API recommendation approach that taps into the predictive power of repetitive code changes to provide relevant API recommendations for developers. Our approach and tool, APIREC, is based on statistical learning from fine-grained code changes and from the context in which those changes were made. Our empirical evaluation shows that APIREC correctly recommends an API call in the first position 59% of the time, and it recommends the correct API call in the top five positions 77% of the time. This is a significant improvement over the state-of-the-art approaches by 30-160% for top-1 accuracy, and 10-30% for top-5 accuracy, respectively. Our result shows that APIREC performs well even with a one-time, minimal training dataset of 50 publicly available projects.