1 files changed, 25 insertions, 4 deletions
diff --git a/activesupport/lib/active_support/deprecation/proxy_wrappers.rb b/activesupport/lib/active_support/deprecation/proxy_wrappers.rb
index 56f1e23136..d7d3c30b97 100644
--- a/activesupport/lib/active_support/deprecation/proxy_wrappers.rb
+++ b/activesupport/lib/active_support/deprecation/proxy_wrappers.rb
@@ -120,9 +120,16 @@ module ActiveSupport
     #   # => DEPRECATION WARNING: PLANETS is deprecated! Use PLANETS_POST_2006 instead.
     #        (Backtrace information…)
     #        ["Mercury", "Venus", "Earth", "Mars", "Jupiter", "Saturn", "Uranus", "Neptune"]
-    class DeprecatedConstantProxy < DeprecationProxy
+    class DeprecatedConstantProxy < Module
+      def self.new(*args, &block)
+        object = args.first
+
+        return object unless object
+        super
+      end
+
       def initialize(old_const, new_const, deprecator = ActiveSupport::Deprecation.instance, message: "#{old_const} is deprecated! Use #{new_const} instead.")
-        require "active_support/inflector/methods"
+        Kernel.require "active_support/inflector/methods"
 
         @old_const = old_const
         @new_const = new_const
@@ -130,6 +137,14 @@ module ActiveSupport
         @message = message
       end
 
+      instance_methods.each { |m| undef_method m unless /^__|^object_id$/.match?(m) }
+
+      # Don't give a deprecation warning on inspect since test/unit and error
+      # logs rely on it for diagnostics.
+      def inspect
+        target.inspect
+      end
+
       # Returns the class of the new constant.
       #
       #   PLANETS_POST_2006 = %w(mercury venus earth mars jupiter saturn uranus neptune)
@@ -144,8 +159,14 @@ module ActiveSupport
           ActiveSupport::Inflector.constantize(@new_const.to_s)
         end
 
-        def warn(callstack, called, args)
-          @deprecator.warn(@message, callstack)
+        def const_missing(name)
+          @deprecator.warn(@message, caller_locations)
+          target.const_get(name)
+        end
+
+        def method_missing(called, *args, &block)
+          @deprecator.warn(@message, caller_locations)
+          target.__send__(called, *args, &block)
         end
     end
   end