As a general rule changes to p11-kit should have a tests exercising that change. Use the make check command to run all the tests. If you run it from a subdirectory only the tests in that directory will be run.

To check for memory errors or memory leaks, run make memcheck or make leakcheck respectively. This requires valgrind be installed.

Build p11-kit with the --enable-coverage configure option to build code coverage support.

Once you've done that you can either use make coverage to build code coverage information. Alternatively (and this is usually easier) you can use git coverage to easily check whether you've tested the lines changed by a patch.

A code coverage report is available online