Running PHPUnit in multiple submodules

I have some modules that i would like to run PHPUnit upon. I might be on the wrong track, but for my CI and CD i would like to run the PHPUnit test on each of the submodules that is available in the system. (Im using git submodule & composer)

I would like to run the PHPUnit on all the modules available, is this somehow possible from a single PHPUnit file or some simple command from composer?