  Healthcare Internet of Things (IoT) applications require rigorous testing to
ensure their dependability. Such applications are typically integrated with
various third-party healthcare applications and medical devices through REST
APIs. This integrated network of healthcare IoT applications leads to REST APIs
with complicated and interdependent structures, thus creating a major challenge
for automated system-level testing. We report an industrial evaluation of a
state-of-the-art REST APIs testing approach (RESTest) on a real-world
healthcare IoT application. We analyze the effectiveness of RESTest's testing
strategies regarding REST APIs failures, faults in the application, and REST
API coverage, by experimenting with six REST APIs of 41 API endpoints of the
healthcare IoT application. Results show that several failures are discovered
in different REST APIs with ~56% coverage using RESTest. Moreover, nine
potential faults are identified. Using the evidence collected from the
experiments, we provide our experiences and lessons learned.
