In my day job as an Electron Inconveniencer, I work heavily with a web development framework called Grails. I fricking love that thing, and all its model-view-controller goodness.
There are a lot of options for testing your code in Grails, including jUnit, and the Spock framework.
Of the places I've been that use Grails, none has really ever done testing well. It's all been sort of ad-hoc and an afterthought. My current gig really wants to do something about that though, and have asked me to lead that charge.
I found a fantastic YouTube video all about how to test your Grails app from stem to stern. It's so good.
if you really want to watch it, and have about 90 minutes to spare, check it out.