2 files changed, 25 insertions, 0 deletions
diff --git a/actionpack/lib/action_dispatch/system_testing/browser.rb b/actionpack/lib/action_dispatch/system_testing/browser.rb
index c34907b6cb..e861e52f09 100644
--- a/actionpack/lib/action_dispatch/system_testing/browser.rb
+++ b/actionpack/lib/action_dispatch/system_testing/browser.rb
@@ -39,6 +39,29 @@ module ActionDispatch
           end
       end
 
+      # driver_path can be configured as a proc. The webdrivers gem uses this
+      # proc to update web drivers. Running this proc early allows us to only
+      # update the webdriver once and avoid race conditions when using
+      # parallel tests.
+      def preload
+        case type
+        when :chrome
+          if ::Selenium::WebDriver::Service.respond_to? :driver_path=
+            ::Selenium::WebDriver::Chrome::Service.driver_path.try(:call)
+          else
+            # Selenium <= v3.141.0
+            ::Selenium::WebDriver::Chrome.driver_path
+          end
+        when :firefox
+          if ::Selenium::WebDriver::Service.respond_to? :driver_path=
+            ::Selenium::WebDriver::Firefox::Service.driver_path.try(:call)
+          else
+            # Selenium <= v3.141.0
+            ::Selenium::WebDriver::Firefox.driver_path
+          end
+        end
+      end
+
       private
         def headless_chrome_browser_options
           capabilities.args << "--headless"
diff --git a/actionpack/lib/action_dispatch/system_testing/driver.rb b/actionpack/lib/action_dispatch/system_testing/driver.rb
index 25a09dd918..15943a55ea 100644
--- a/actionpack/lib/action_dispatch/system_testing/driver.rb
+++ b/actionpack/lib/action_dispatch/system_testing/driver.rb
@@ -9,6 +9,8 @@ module ActionDispatch
         @screen_size = options[:screen_size]
         @options = options[:options]
         @capabilities = capabilities
+
+        @browser.preload
       end
 
       def use