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.
= Background
In T160238 and T164024 we rewrite our other browser tests. MinervaNeue has a significant amount of browser tests so is likely to take much longer but hopefully we've had enough practice to do this.
Minerva has been setup so that you can run browser tests using `check experimental`
A patch has been begun in [[ https://gerrit.wikimedia.org/r/373902 | WIP Port Minerva's browser tests to Selenium ]]
= Acceptance criteria
[] Rewrite all tests into Node.js
[] Make the experimental job the default. Drop the old Ruby job.
[] While working on this, do an audit as originally proposed in T148973 of what we are testing. Remove unnecessary tests and document missing tests. At the end, [[ https://www.mediawiki.org/wiki/Reading/Web/Browser_test_coverage | summarise the browser test for each extension. ]]