1 files changed, 65 insertions, 0 deletions
diff --git a/lib/chef/mixin/deprecation.rb b/lib/chef/mixin/deprecation.rb
new file mode 100644
index 0000000000..cc85c4e976
--- /dev/null
+++ b/lib/chef/mixin/deprecation.rb
@@ -0,0 +1,65 @@
+#
+# Author:: Daniel DeLeo (<dan@opscode.com>)
+# Copyright:: Copyright (c) 2010 Opscode, Inc.
+# License:: Apache License, Version 2.0
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+class Chef
+  module Mixin
+    module Deprecation
+      class DeprecatedObjectProxyBase
+        KEEPERS = %w{__id__ __send__ instance_eval == equal? initialize object_id}
+        instance_methods.each { |method_name| undef_method(method_name) unless KEEPERS.include?(method_name.to_s)}
+      end
+
+      class DeprecatedInstanceVariable < DeprecatedObjectProxyBase
+        def initialize(target, ivar_name, level=nil)
+          @target, @ivar_name = target, ivar_name
+          @level ||= :warn
+        end
+
+        def method_missing(method_name, *args, &block)
+          log_deprecation_msg(caller[0..3])
+          @target.send(method_name, *args, &block)
+        end
+
+        def inspect
+          @target.inspect
+        end
+
+        private
+
+        def log_deprecation_msg(*called_from)
+          called_from = called_from.flatten
+          log("Accessing #{@ivar_name} by the variable @#{@ivar_name} is deprecated. Support will be removed in a future release.")
+          log("Please update your cookbooks to use #{@ivar_name} in place of @#{@ivar_name}. Accessed from:")
+          called_from.each {|l| log(l)}
+        end
+
+        def log(msg)
+          # WTF: I don't get the log prefix (i.e., "[timestamp] LEVEL:") if I
+          # send to Chef::Log. No one but me should use method_missing, ever.
+          Chef::Log.logger.send(@level, msg)
+        end
+
+      end
+
+      def deprecated_ivar(obj, name, level=nil)
+        DeprecatedInstanceVariable.new(obj, name, level)
+      end
+
+    end
+  end
+end