What is the current state of art for testing JS based functionality of Plone?
For long we loved everything to be runnable through zope.testrunner. But AFAIK , related to JS based functionality, we can currently only run acceptance tests thorugh zope.testrunner (via RobotFramework and Selenium).
But how about JS unittests?
For some time ago we did have experimental BusterJS integration for zope.testrunner created at Sea Sprint and those tests were even run at jenkins.plone.org for some time.
But BusterJS seems to be abandoned a year ago and the current black is testing with a webpack based setup.