1 files changed, 43 insertions, 0 deletions
diff --git a/lib/chef/decorator/unchain.rb b/lib/chef/decorator/unchain.rb
new file mode 100644
index 0000000000..30179d4e63
--- /dev/null
+++ b/lib/chef/decorator/unchain.rb
@@ -0,0 +1,43 @@
+class Chef
+  class Decorator < SimpleDelegator
+    #
+    # This decorator unchains method call chains and turns them into method calls
+    # with variable args.  So this:
+    #
+    #   node.set_unless["foo"]["bar"] = "baz"
+    #
+    # Can become:
+    #
+    #   node.set_unless("foo", "bar", "baz")
+    #
+    # While this is a decorator it is not a Decorator and does not inherit because
+    # it deliberately does not need or want the method_missing magic.  It is not legal
+    # to call anything on the intermediate values and only supports method chaining with
+    # #[] until the chain comes to an end with #[]=, so does not behave like a hash or
+    # array...  e.g.
+    #
+    #   node.default['foo'].keys is legal
+    #   node.set_unless['foo'].keys is not legal now or ever
+    #
+    class Unchain
+      attr_accessor :__path__
+      attr_accessor :__method__
+
+      def initialize(obj, method)
+        @__path__        = []
+        @__method__      = method
+        @delegate_sd_obj = obj
+      end
+
+      def [](key)
+        __path__.push(key)
+        self
+      end
+
+      def []=(key, value)
+        __path__.push(key)
+        @delegate_sd_obj.public_send(__method__, *__path__, value)
+      end
+    end
+  end
+end