Currently we have close to no unittests for the code that interacts with BlueZ over DBus. We've started with one test bluetooth_gatt_application_service_provider_unittest.cc which verifies the output of the DBus call against a fixed string. Even though this isn't a great way of testing, it is much better than nothing.

We need to add the ability to write this kind of a test easily for other DBus components that talk to BlueZ. Ideally we should have a small framework that allows a developer to specify the DBus object provider and an expected DBus output.

Without these tests this code is very brittle. We've had bugs happen often due to unexpected changes that were never caught due to a complete lack of testing in this area.