Understanding device integration bugs in smart home system

Smart devices have been widely adopted in our daily life. A smart home system, e.g., Home Assistant and openHAB, can be equipped with hundreds and even thousands of smart devices. A smart home system communicates with smart devices through various device integrations, each of which is responsible for a specific kind of devices. Developing high-quality device integrations is a challenging task, in which developers have to properly handle the heterogeneity of different devices, unexpected exceptions, etc. We find that device integration bugs, i.e., iBugs, are prevalent and have caused various consequences, e.g., causing devices unavailable, unexpected device behaviors. In this paper, we conduct the first empirical study on 330 iBugs in Home Assistant, the most popular open source smart home system. We investigate their root causes, trigger conditions, impacts, and fixes. From our study, we obtain many interesting findings and lessons that are helpful for device integration developers and smart home system designers. Our study can open up new research directions for combating iBugs in smart home systems.