AS::BasicObject can be inherited from

2 files changed, 19 insertions, 2 deletions

diff --git a/activesupport/lib/active_support/basic_object.rb b/activesupport/lib/active_support/basic_object.rb
index 242b766b58..d4d06b2aa4 100644
--- a/activesupport/lib/active_support/basic_object.rb
+++ b/activesupport/lib/active_support/basic_object.rb
@@ -1,7 +1,12 @@
 require 'active_support/deprecation'
+require 'active_support/proxy_object'
 
 module ActiveSupport
   # :nodoc:
-  # Deprecated in favor of ActiveSupport::ProxyObject
-  BasicObject = Deprecation::DeprecatedConstantProxy.new('ActiveSupport::BasicObject', 'ActiveSupport::ProxyObject')
+  class BasicObject < ProxyObject
+    def self.inherited(*)
+      ::ActiveSupport::Deprecation.warn 'ActiveSupport::BasicObject is deprecated! Use ActiveSupport::ProxyObject instead.'
+      super
+    end
+  end
 end
diff --git a/activesupport/test/deprecation/basic_object_test.rb b/activesupport/test/deprecation/basic_object_test.rb
new file mode 100644
index 0000000000..4b5bed9eb1
--- /dev/null
+++ b/activesupport/test/deprecation/basic_object_test.rb
@@ -0,0 +1,12 @@
+require 'abstract_unit'
+require 'active_support/deprecation'
+require 'active_support/basic_object'
+
+
+class BasicObjectTest < ActiveSupport::TestCase
+  test 'BasicObject warns about deprecation when inherited from' do
+    warn = 'ActiveSupport::BasicObject is deprecated! Use ActiveSupport::ProxyObject instead.'
+    ActiveSupport::Deprecation.expects(:warn).with(warn).once
+    Class.new(ActiveSupport::BasicObject)
+  end
+end
\ No newline at end of file