Proactive Empirical Assessment of New Language Feature Adoption via Automated Refactoring: The Case of Java 8 Default Methods

Programming languages and platforms improve over time, sometimes resulting in new language features that offer many benefits. However, despite these benefits, developers may not always be willing to adopt them in their projects for various reasons. In this paper, we describe an empirical study where we assess the adoption of a particular new language feature. Studying how developers use (or do not use) new language features is important in programming language research and engineering because it gives designers insight into the usability of the language to create meaning programs in that language. This knowledge, in turn, can drive future innovations in the area. Here, we explore Java 8 default methods, which allow interfaces to contain (instance) method implementations. Default methods can ease interface evolution, make certain ubiquitous design patterns redundant, and improve both modularity and maintainability. A focus of this work is to discover, through a scientific approach and a novel technique, situations where developers found these constructs useful and where they did not, and the reasons for each. Although several studies center around assessing new language features, to the best of our knowledge, this kind of construct has not been previously considered. Despite their benefits, we found that developers did not adopt default methods in all situations. Our study consisted of submitting pull requests introducing the language feature to 19 real-world, open source Java projects without altering original program semantics. This novel assessment technique is proactive in that the adoption was driven by an automatic refactoring approach rather than waiting for developers to discover and integrate the feature themselves. In this way, we set forth best practices and patterns of using the language feature effectively earlier rather than later and are able to possibly guide (near) future language evolution. We foresee this technique to be useful in assessing other new language features, design patterns, and other programming idioms

Towards the Automation of Migration and Safety of Third-Party Libraries

The process of migration from one library to a new, different library is very complex. Typically, the developer needs to find functions in the new library that are most adequate in replacing the functions of the retired library. This process is subjective and time-consuming as the developer needs to fully understand the documentation of both libraries to be able to migrate from an old library to a new one and find the right matching function(s) if exists. Our goal is helping the developer to have better experiences with library migration by identifying the key problems related to this process. Based on our critical literature review, we identified three main challenges related to the automation of library migration: (1) the mining of existing migrations, (2) learning from these migrations to recommend them in similar contexts, and (3) guaranteeing the safety of the recommended migrations