We are working with a vendor that has a proprietary web browser based on chromium. I am wondering if it is possible to use selenium and the ChromeDriver to run tests with this browser. I tried specifying the executable in the driver options. The browsers opens, but the test errors out because the driver object is null. That is as far as I have tried. I'm posting here to see if what I want to do is even possible.
It depends how customized it is. If it implements everything for WebDriver communication identical to Chromium, then it will work with ChromeDriver (and therefore Selenium), otherwise it will not.
You will most likely run into issues, because Chrome/Chromium and ChromeDriver are updated in tandem to accommodate changes in the browser... and your custom browser will be out of sync.
As an example, Selenium supports Microsoft Edge, which is Chromium based. However, this requires a custom WebDriver (EdgeDriver) from Microsoft and special classes in the Selenium bindings. It doesn't just work out of the box with the Chrome/Chromium classes and ChromeDriver.