Note: This task is large and it's not clear how to break it down. https://www.mediawiki.org/wiki/User_talk:Jdlrobson/Experiences_porting_Ruby_browser_tests_to_NodeJs provides a good summary of the problems we faced when trying to do this before. This is stalled on T177260 being completed first which is also a large task, but will help us achieve this one more quickly.
Minerva has been setup so that you can run browser tests using check experimental
A patch has been begun in WIP Port Minerva's browser tests to Selenium