I have downloaded CommonDomain from GitHub and I can see a directory
/ src / tests / CommonDomain.AcceptanceTests
which contains the file "When_an_aggregate_is_persisted.cs" but there is no project that uses it. Also the base class "in_the_event_store" seems to be missing. There are also references to FakeBus, IDomainEvent, SynchronousDispatcher etc.
CommonDomain is not under any kind of test. There are some old files that were under some kind of test at one point but the test files were removed from the solution at one point. The CommonDomain project was originally spike code (proof of concept) that worked a little bit too well and made it into production. Interestingly enough, there are actually quite a few users that use it now because it's extremely lightweight and tries to be as unobtrusive as possible.
The future of this project is to merge its essence into the EventStore project because the are two sides of the same coin. But the new iteration will be under a full suite of tests.