Do not take screenshot if driver does not support screenshot

`Capybara::RackTest::Driver` does not support taking screenshots. If call
`#save_screenshot` on `Capybara::RackTest::Driver` will raise the error.

```ruby
Error:
UsersTest#test_visiting_the_index:
Capybara::NotSupportedByDriverError: Capybara::Driver::Base#save_screenshot
```

To prevent errors, if driver does not support screenshot, do not call it.

1 files changed, 5 insertions, 1 deletions

diff --git a/actionpack/lib/action_dispatch/system_testing/test_helpers/screenshot_helper.rb b/actionpack/lib/action_dispatch/system_testing/test_helpers/screenshot_helper.rb
index ddc961cf84..e37f6d02aa 100644
--- a/actionpack/lib/action_dispatch/system_testing/test_helpers/screenshot_helper.rb
+++ b/actionpack/lib/action_dispatch/system_testing/test_helpers/screenshot_helper.rb
@@ -22,7 +22,7 @@ module ActionDispatch
         # fails add +take_failed_screenshot+ to the teardown block before clearing
         # sessions.
         def take_failed_screenshot
-          take_screenshot if failed?
+          take_screenshot if failed? && supports_screenshot?
         end
 
         private
@@ -55,6 +55,10 @@ module ActionDispatch
           def failed?
             !passed? && !skipped?
           end
+
+          def supports_screenshot?
+            page.driver.public_methods(false).include?(:save_screenshot)
+          end
       end
     end
   end