Chrome Extension tessting DOM manipulation

I am a developer of a Chrome Extesion that manipulates the DOM of a specific website, to add things such as colour themes to it. We got the idea that having some tests set up for our code was a good idea, however I cannot seem to find a testing stack that will allow me to do this.

I would like to have tests that would modify the extension settings menu, and then check the results on the DOM of the specific website.

What is the optimal testing stack for this case?