1 files changed, 25 insertions, 7 deletions
diff --git a/activesupport/lib/active_support/deprecation.rb b/activesupport/lib/active_support/deprecation.rb
index 758aef5445..ebdaf86146 100644
--- a/activesupport/lib/active_support/deprecation.rb
+++ b/activesupport/lib/active_support/deprecation.rb
@@ -144,17 +144,11 @@ module ActiveSupport
         end
     end
 
-    # Stand-in for <tt>@request</tt>, <tt>@attributes</tt>, <tt>@params</tt>, etc.
-    # which emits deprecation warnings on any method call (except +inspect+).
-    class DeprecatedInstanceVariableProxy #:nodoc:
+    class DeprecationProxy #:nodoc:
       silence_warnings do
         instance_methods.each { |m| undef_method m unless m =~ /^__/ }
       end
 
-      def initialize(instance, method, var = "@#{method}")
-        @instance, @method, @var = instance, method, var
-      end
-
       # Don't give a deprecation warning on inspect since test/unit and error
       # logs rely on it for diagnostics.
       def inspect
@@ -166,7 +160,16 @@ module ActiveSupport
           warn caller, called, args
           target.__send__(called, *args, &block)
         end
+    end
 
+    # Stand-in for <tt>@request</tt>, <tt>@attributes</tt>, <tt>@params</tt>, etc.
+    # which emits deprecation warnings on any method call (except +inspect+).
+    class DeprecatedInstanceVariableProxy < DeprecationProxy #:nodoc:
+      def initialize(instance, method, var = "@#{method}")
+        @instance, @method, @var = instance, method, var
+      end
+
+      private
         def target
           @instance.__send__(@method)
         end
@@ -176,6 +179,21 @@ module ActiveSupport
         end
     end
 
+    class DeprecatedConstantProxy < DeprecationProxy #:nodoc:
+      def initialize(old_const, new_const)
+        @old_const = old_const
+        @new_const = new_const
+      end
+
+      private
+        def target
+          @new_const.to_s.constantize
+        end
+
+        def warn(callstack, called, args)
+          ActiveSupport::Deprecation.warn("#{@old_const} is deprecated! Use #{@new_const} instead.", callstack)
+        end
+    end
   end
 end