Automated testing of Tracker
Provided by distros
Ubuntu autopkgtest: https://autopkgtest.ubuntu.com/packages/tracker/
Debian reproducible-builds: https://tests.reproducible-builds.org/tracker/
OpenSuSE do automated whole-system testing that includes the GNOME desktop for their Tumbleweed rolling release distro: https://openqa.opensuse.org/group_overview/1
To run yourself
Tracker contains many unit tests which you can execute using the normal make check command.
Tracker also has a ../Documentation/FunctionalTesting. It is fairly bit rotten though.