Add tests for explicit engines.

3 files changed, 21 insertions, 13 deletions

diff --git a/railties/lib/rails/application.rb b/railties/lib/rails/application.rb
index eba49e1520..12aa279959 100644
--- a/railties/lib/rails/application.rb
+++ b/railties/lib/rails/application.rb
@@ -6,6 +6,7 @@ require 'rails/engine'
 module Rails
   class Application < Engine
     autoload :Bootstrap,      'rails/application/bootstrap'
+    autoload :Configurable,   'rails/application/configurable'
     autoload :Configuration,  'rails/application/configuration'
     autoload :Finisher,       'rails/application/finisher'
     autoload :Railties,       'rails/application/railties'
@@ -41,10 +42,6 @@ module Rails
       require environment if environment
     end
 
-    def config
-      @config ||= Application::Configuration.new(self.class.find_root_with_flag("config.ru", Dir.pwd))
-    end
-
     def routes
       ::ActionController::Routing::Routes
     end
diff --git a/railties/lib/rails/application/configurable.rb b/railties/lib/rails/application/configurable.rb
new file mode 100644
index 0000000000..f598e33965
--- /dev/null
+++ b/railties/lib/rails/application/configurable.rb
@@ -0,0 +1,19 @@
+module Rails
+  class Application
+    module Configurable
+      def self.included(base)
+        base.extend ClassMethods
+      end
+
+      module ClassMethods
+        def inherited(base)
+          raise "You cannot inherit from a Rails::Application child"
+        end
+      end
+
+      def config
+        @config ||= Application::Configuration.new(self.class.find_root_with_flag("config.ru", Dir.pwd))
+      end
+    end
+  end
+end
\ No newline at end of file
diff --git a/railties/lib/rails/railtie.rb b/railties/lib/rails/railtie.rb
index 3cf358d75f..c038d0ac70 100644
--- a/railties/lib/rails/railtie.rb
+++ b/railties/lib/rails/railtie.rb
@@ -17,7 +17,7 @@ module Rails
 
       def inherited(base)
         unless abstract_railtie?(base)
-          base.send(:include, self::Configurable) if add_configurable?(base)
+          base.send(:include, self::Configurable)
           subclasses << base
         end
       end
@@ -53,14 +53,6 @@ module Rails
       def abstract_railtie?(base)
         ABSTRACT_RAILTIES.include?(base.name)
       end
-
-      # Just add configurable behavior if a Configurable module is defined
-      # and the class is a direct child from self. This is required to avoid
-      # application or plugins getting class configuration method from Railties
-      # and/or Engines.
-      def add_configurable?(base)
-        defined?(self::Configurable) && base.ancestors[1] == self
-      end
     end
 
     def rake_tasks