Merge pull request #13 from chrisroberts/enhancement/option-inheritance

[MIXLIB-14] Option inheritance

1 files changed, 40 insertions, 1 deletions

diff --git a/lib/mixlib/cli.rb b/lib/mixlib/cli.rb
index 887d05f..9d7d596 100644
--- a/lib/mixlib/cli.rb
+++ b/lib/mixlib/cli.rb
@@ -38,8 +38,46 @@ module Mixlib
   # #parse_options. After calling this method, the attribute #config will
   # contain a hash of `:option_name => value` pairs.
   module CLI
-    module ClassMethods
 
+    module InheritMethods
+      def inherited(receiver)
+        receiver.options = deep_dup(self.options)
+        receiver.extend(Mixlib::CLI::InheritMethods)
+      end
+
+      # object:: Instance to clone
+      # This method will return a "deep clone" of the provided
+      # `object`. If the provided `object` is an enumerable type the
+      # contents will be iterated and cloned as well.
+      def deep_dup(object)
+        cloned_object = object.respond_to?(:dup) ? object.dup : object
+        if(cloned_object.kind_of?(Enumerable))
+          if(cloned_object.kind_of?(Hash))
+            new_hash = cloned_object.class.new
+            cloned_object.each do |key, value|
+              cloned_key = deep_dup(key)
+              cloned_value = deep_dup(value)
+              new_hash[cloned_key] = cloned_value
+            end
+            cloned_object.replace(new_hash)
+          else
+            cloned_object.map! do |shallow_instance|
+              deep_dup(shallow_instance)
+            end
+          end
+        end
+        cloned_object
+      rescue TypeError
+        # Symbol will happily provide a `#dup` method even though
+        # attempts to clone it will result in an exception (atoms!).
+        # So if we run into an issue of TypeErrors, just return the
+        # original object as we gave our "best effort"
+        object
+      end
+
+    end
+
+    module ClassMethods
       # When this setting is set to +true+, default values supplied to the
       # mixlib-cli DSL will be stored in a separate Hash
       def use_separate_default_options(true_or_false)
@@ -273,6 +311,7 @@ module Mixlib
 
     def self.included(receiver)
       receiver.extend(Mixlib::CLI::ClassMethods)
+      receiver.extend(Mixlib::CLI::InheritMethods)
     end
 
   end