We use Boost::Test to test our code.
The full list of unit tests is found in system/CMakeLists.txt. Here, a macro add_check is used to define a test and tell whether it is currently expected to pass or fail.
Each test defined in this way creates two targets: *.test which builds the test, and check-*, which runs the test. In addition, there are aggregate targets check-all-{pass,fail} which build and run all the passing or failing tests respectively, and check-all-{pass,fail}-compile-only which, as the name implies, only compiles them.
Non-exhaustive list of test targets:
New_loop_tests.test: build loop testscheck-New_loop_tests: build and run loop testscheck-all-pass: build and run all passing testscheck-all-pass-compile-only: just build all the tests expected to pass
Someday we'll get this up and running with some CI server, but until then, we just try and run it whenever we make significant changes.