Don't call register on custom drivers

It's possible for developers toadd a custom driver and then call it
using `driven_by`. Because we were only skipping `register` for
`:rack_test` that meant any custom driver would attempt to be registered
as well.

The three listed here are special because Rails registers them with
special options. If you're registering your own custom driver then you
don't want to separately register that driver.

Fixes #29688

1 files changed, 3 insertions, 3 deletions

diff --git a/actionpack/lib/action_dispatch/system_testing/driver.rb b/actionpack/lib/action_dispatch/system_testing/driver.rb
index 1a027f2e23..81e6f0fc80 100644
--- a/actionpack/lib/action_dispatch/system_testing/driver.rb
+++ b/actionpack/lib/action_dispatch/system_testing/driver.rb
@@ -9,14 +9,14 @@ module ActionDispatch
       end
 
       def use
-        register unless rack_test?
+        register if registerable?
 
         setup
       end
 
       private
-        def rack_test?
-          @name == :rack_test
+        def registerable?
+          [:selenium, :poltergeist, :webkit].include?(@name)
         end
 
         def register