Data-Driven Solutions to Detect API Compatibility Issues in Android: An Empirical Study

Android apps are inextricably linked to the official Android APIs. Such a strong form of dependency implies that changes introduced in new versions of the Android APIs can severely impact the apps' code, for example because of deprecated or removed APIs. In reaction to those changes, mobile app developers are expected to adapt their code and avoid compatibility issues. To support developers, approaches have been proposed to automatically identify API compatibility issues in Android apps. The state-of-the-art approach, named CiD, is a data-driven solution learning how to detect those issues by analyzing the changes in the history of Android APIs ("API side" learning). While it can successfully identify compatibility issues, it cannot recommend coding solutions. We devised an alternative data-driven approach, named ACRYL. ACRYL learns from changes implemented in other apps in response to API changes ("client side" learning). This allows not only to detect compatibility issues, but also to suggest a fix. When empirically comparing the two tools, we found that there is no clear winner, since the two approaches are highly complementary, in that they identify almost disjointed sets of API compatibility issues. Our results point to the future possibility of combining the two approaches, trying to learn detection/fixing rules on both the API and the client side.