What are the best approaches / tools to test browser extensions?
In my case I work on an IE Browser Helper Object (C#) which has a small UI of its own and a good deal of database interaction. Up till now we've used automated unit tests for testing our model/business objects but manual testing for the UI/scenario testing. I'm thinking of starting to use Selenium for control of the browser, and then will need to add to it some other scripting to control and assert behaviour of my UI elements and check the database for correct results.
Any recommendations? What does anyone else in a similar situation do (whether developing BHOs or Firefox Extensions or whatever)?