CI should look at submitted patches and, if possible, build them and report back on build status, test coverage and stuff. Harbormaster has some support for it. A somewhat oldish howto is here but the Jenkins plugins for phabricator may have changed/improved by now.

Somewhat related: T3113: Integrate gnupg commit message style in arc (which is useful to submit patches with arc, which makes it more reliable to attribute the patch to the right repo and version).