Test environment running in www.example.com domain

I noticed that my tests are run in the www.example.com domain. I'm using rspec and capybara, so `visit sports_url` tries to visit www.example.com/sports. This works fine with the default test driver, but I have some javascript that I need to test. These tests fail because the browser tries to access www.example.com/sports (which obviously doesn't exist). The browser is used by the selenium driver of capybara to test javascript. If I use `visit sports_path` the local web server is access with both the standard and selenium drivers.

Should I be configuring the test environment somehow to NOT be running as www.example.com? Or am I testing in the wrong way?

Thanks