[vaviloff]

This is great, starred! I like how you went beyond the usual "render page to png/pdf with CDP" stuff and made evaluate/exists/set screen size methods - one can see it's made for real use.

This could become a cool replacement for PhantomJS that people would actually use! I answer questions about PhantomJS on SO now and then - there are lots of questions on how to login to a site and download something while in a session, so - here's another idea for real world use: download to local fs method.

Other features people use often:

  * waiting for (an element/set amount of time), 
  * event for when a page has (re)loaded, to check if login/submit was successful
  * aborting select network requests - useful for scraping/testing

So, good luck on this project!