Karma, Mocha, Chrome Headless and click testing on an url

Question

I'm trying to use Karma & Chrome Headless to replace testing I would have done with CasperJS & PhantomJS to load a public site for running end to end click testing.

The idea is that this would be an automated test against a canary server to ensure functionality like login, signup, etc. behaves as expected. I've gotten simple test loading examples up and running with Karma, Mocha, Chai, & Chrome Headless but I can't figure out how to navigate to an url via the test and then check/click on DOM elements.

I haven't found any useful documentation or examples to point me in the right direction.