The tests are written in Jasmine. They are run as part of the maven build, in the “test” step of the lifecycle, by this plugin: https://github.com/openmrs/openmrs-module-uicommons/blob/712b5bd662451fb51f22e451af3a8e5ec276234a/omod/pom.xml#L188
If you want to run only those tests, and be able to re-run them quickly (e.g. you’re debugging or writing more tests) you can go to the omod folder, and then do
mvn jasmine:bdd. You then open a browser window to the url it tells you.
(@mahovsven Please help us put these instructions in the right place, e.g. at least in the README.md of the module, but maybe somewhere else that you would have looked! Can you send a pull request with this, or edit a wiki page, or something?)