> You're having difficulty finding instructions on how to do this because running Rubberduck tests from the command line not a feature that's available.
Also, you _could_ call the tests in the test modules from code in other modules, just as you would call any method in any module in VBA, there is a test run dialog box designed to make it easy to run the tests.
Considering that testing in this manner was never a though when VBA was designed and that it wasn't built into the last release