1 files changed, 10 insertions, 17 deletions
diff --git a/railties/test/application/configuration/custom_test.rb b/railties/test/application/configuration/custom_test.rb
index 28b3b2f2d6..05b17b4a7a 100644
--- a/railties/test/application/configuration/custom_test.rb
+++ b/railties/test/application/configuration/custom_test.rb
@@ -1,20 +1,20 @@
-require 'isolation/abstract_unit'
+# frozen_string_literal: true
+
+require "isolation/abstract_unit"
 
 module ApplicationTests
   module ConfigurationTests
     class CustomTest < ActiveSupport::TestCase
       def setup
         build_app
-        boot_rails
         FileUtils.rm_rf("#{app_path}/config/environments")
       end
 
       def teardown
         teardown_app
-        FileUtils.rm_rf(new_app) if File.directory?(new_app)
       end
 
-      test 'access custom configuration point' do
+      test "access custom configuration point" do
         add_to_config <<-RUBY
           config.x.payment_processing.schedule = :daily
           config.x.payment_processing.retries  = 3
@@ -29,23 +29,16 @@ module ApplicationTests
         assert_equal 3, x.payment_processing.retries
         assert_equal true, x.super_debugger
         assert_equal false, x.hyper_debugger
-        assert_equal nil, x.nil_debugger
+        assert_nil x.nil_debugger
         assert_nil x.i_do_not_exist.zomg
+
+        # test that custom configuration responds to all messages
+        assert_equal true, x.respond_to?(:i_do_not_exist)
+        assert_kind_of Method, x.method(:i_do_not_exist)
+        assert_kind_of ActiveSupport::OrderedOptions, x.i_do_not_exist
       end
 
       private
-        def new_app
-          File.expand_path("#{app_path}/../new_app")
-        end
-
-        def copy_app
-          FileUtils.cp_r(app_path, new_app)
-        end
-
-        def app
-          @app ||= Rails.application
-        end
-
         def require_environment
           require "#{app_path}/config/environment"
         end