1 files changed, 44 insertions, 0 deletions
diff --git a/railties/test/application/rackup_test.rb b/railties/test/application/rackup_test.rb
new file mode 100644
index 0000000000..383f18a7da
--- /dev/null
+++ b/railties/test/application/rackup_test.rb
@@ -0,0 +1,44 @@
+# frozen_string_literal: true
+
+require "isolation/abstract_unit"
+
+module ApplicationTests
+  class RackupTest < ActiveSupport::TestCase
+    include ActiveSupport::Testing::Isolation
+
+    def rackup
+      require "rack"
+      app, _ = Rack::Builder.parse_file("#{app_path}/config.ru")
+      app
+    end
+
+    def setup
+      build_app
+    end
+
+    def teardown
+      teardown_app
+    end
+
+    test "Rails app is present" do
+      assert File.exist?(app_path("config"))
+    end
+
+    test "config.ru can be racked up" do
+      Dir.chdir app_path do
+        @app = rackup
+        assert_welcome get("/")
+      end
+    end
+
+    test "Rails.application is available after config.ru has been racked up" do
+      rackup
+      assert_kind_of Rails::Application, Rails.application
+    end
+
+    test "the config object is available on the application object" do
+      rackup
+      assert_equal "UTC", Rails.application.config.time_zone
+    end
+  end
+end