DFS is working

lib/pruner.rb

@@ -2,25 +2,35 @@ module Pruning
   module Processing
     class Pruner
 
-      def initialize(tree, indicator_ids)
+      def initialize(tree)
         @tree = tree
       end
 
-      def prune_tree(nodes, indicator_ids)
-        nodes.delete_if do |node|
-          unwanted_indicator = indicator_node?(node) && !indicator_ids.include?(node['id'])  
-          has_no_wanted_indicators_in_children = prune_tree(children(node), indicator_ids)
-
-          unwanted_indicator && has_no_wanted_indicators_in_children 
-        end 
-        nodes.empty?
+      def prune_tree(indicator_ids)
+        pruned_tree = @tree.dup
+        prune_subtree(pruned_tree, indicator_ids)
+        pruned_tree
       end
 
       private
+      def prune_subtree(nodes, indicator_ids)
+        nodes_to_examine = nodes.dup
+        nodes_to_examine.each do |node|
+          if indicator_node?(node) 
+            unwanted_indicator = !indicator_ids.include?(node['id'])  
+            nodes.delete(node) if unwanted_indicator 
+          else 
+            has_no_wanted_indicators_in_children = prune_subtree(children(node), indicator_ids)
+            nodes.delete(node) if has_no_wanted_indicators_in_children   
+          end
+        end
+        nodes.empty?
+      end
+
       def children(node)
-        node.get('sub-themes', false) ||
-        node.get('categories', false) || 
-        node.get('indicators', false) ||
+        node.fetch('sub_themes', false) ||
+        node.fetch('categories', false) || 
+        node.fetch('indicators', false) ||
         []
       end