whats the best headless browser for CI/CD? I've always used Phantom, but would be keen to explore alternatives (especially if it could quiet the "nobody uses phantom in real life")
For me so far the most pleasant to work with has (contrary to its name) been Nightmare (http://www.nightmarejs.org/), which is a Node.js library that drives Electron. It has a really pleasant API and its developers claim that it is faster than PhantomJS. Unlike PhantomJS, however, it is not truly headless; it needs an X server like xvfb to run.
I write tests using chromedriver. Ends up being really simple to write, and if I want to debug something, it's just a chrome instance that I can use normally if I make the tests wait.
Only downside is you have to make it run with xvfb on the CI server, but that's pretty easy to set up in your config file usually.