DFS is working

lib/api/tree.rb

@@ -15,3 +15,7 @@ module Pruning
     end
   end 
 end
+
+
+
+

lib/http/query.rb

@@ -2,11 +2,12 @@ module Pruning
   module HTTP
     class Query < Struct.new(:name, :indicator_ids)
       def initialize(params = {})
+        symbolised = params.map { |k, v| { k.to_sym => v } }.reduce({}, :merge)
         values = members.map do |member|
-          value = params.fetch(member, nil)
+          value = symbolised.fetch(member, nil)
           next if value.nil?
           case member
-          when :indicator_ids then value.map(&:to_i) # break on purpose if indicator_ids is not an array
+          when :indicator_ids then value.map(&->(indicator_id) { indicator_id.to_i } ) # break on purpose if indicator_ids is not an array
           when :name then value.to_s.gsub(/[^A-Za-z]/,'') 
             else value
           end

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