Add rack_test driver to System Tests

actionpack/lib/action_dispatch/system_testing/driver.rb

@@ -24,7 +24,7 @@ module ActionDispatch
 
       private
         def registerable?
-          [:selenium, :poltergeist, :webkit].include?(@name)
+          [:selenium, :poltergeist, :webkit, :rack_test].include?(@name)
         end
 
         def register
@@ -35,6 +35,7 @@ module ActionDispatch
             when :selenium then register_selenium(app)
             when :poltergeist then register_poltergeist(app)
             when :webkit then register_webkit(app)
+            when :rack_test then register_rack_test(app)
             end
           end
         end
@@ -59,6 +60,10 @@ module ActionDispatch
           end
         end
 
+        def register_rack_test(app)
+          Capybara::RackTest::Driver.new(app, { respect_data_method: true }.merge(@options))
+        end
+
         def setup
           Capybara.current_driver = @name
         end

actionpack/test/dispatch/system_testing/driver_test.rb

@@ -51,10 +51,6 @@ class DriverTest < ActiveSupport::TestCase
     assert_equal ({ skip_image_loading: true }), driver.instance_variable_get(:@options)
   end
 
-  test "registerable? returns false if driver is rack_test" do
-    assert_not ActionDispatch::SystemTesting::Driver.new(:rack_test).send(:registerable?)
-  end
-
   test "define extra capabilities using chrome" do
     driver = ActionDispatch::SystemTesting::Driver.new(:selenium, screen_size: [1400, 1400], using: :chrome) do |option|
       option.add_argument("start-maximized")