How should browser extensions be tested?

Question

Software testing

Hello. I am writing an extension for 3 browsers: FF, Opera, Chrome. The code base is one, taking into account the features of the browser.
Ivot seems to have updated the functionality, ran it manually in "developer mode" (and under FF you also need to sign it before installation), but still something fell off. Well, it’s impossible to take everything into account when testing.
Maybe there is some tool for testing exactly browser extensions?
To describe the scenario of behavior and it performed it for all three browsers. Or at least in semi-automatic mode.
Tell me where to dig.

Answer 1

About the same code - not the fact that it will turn out. But let's say I have a student writing a python script that drags a file from explorer.exe to Google Drive opened in Chrome:
https://github.com/vasily-v-ryabov/ui-automation-c...
For chrome needs a key with "enable accessibility" options (see example above). FF and Opera should include MS UI Automation support by default. Of course, all this will only work under Windows. Although pywinauto is developing for Linux, it is still at an early stage.
If you're interested, it's best to start learning pywinauto with the Getting Started Guide. So faster.