Merge pull request #2010 from alphagov/specify-permitted-next-nodes-for-all-flows

Specify permitted next nodes for all flows

Author: chrisroos

lib/smart_answer/question/base.rb

@@ -15,8 +15,12 @@ def initialize(flow, name, options = {}, &block)
         super
       end
 
-      def next_node(next_node = nil, &block)
+      def next_node(next_node = nil, permitted: [], &block)
         if block_given?
+          unless permitted.any?
+            raise "You must specify the permitted next nodes"
+          end
+          @permitted_next_nodes += permitted
           @default_next_node_function = block
         elsif next_node
           next_node_if(next_node)
@@ -44,6 +48,9 @@ def next_node_for(current_state, input)
         next_node = next_node_from_function_chain(current_state, input) || next_node_from_default_function(current_state, input)
         responses_and_input = current_state.responses + [input]
         raise NextNodeUndefined.new("Next node undefined. Node: #{current_state.current_node}. Responses: #{responses_and_input}") unless next_node
+        unless @permitted_next_nodes.include?(next_node)
+          raise "Next node (#{next_node}) not in list of permitted next nodes (#{@permitted_next_nodes.to_sentence})"
+        end
         next_node
       end
 

lib/smart_answer_flows/additional-commodity-code.rb

@@ -17,7 +17,14 @@ def define
 
         save_input_as :starch_glucose_weight
 
-        next_node do |response|
+        permitted_next_nodes = [
+          :how_much_sucrose_1?,
+          :how_much_sucrose_2?,
+          :how_much_sucrose_3?,
+          :how_much_sucrose_4?
+        ]
+
+        next_node(permitted: permitted_next_nodes) do |response|
           case response.to_i
           when 25
             :how_much_sucrose_2?
@@ -90,7 +97,16 @@ def define
 
         save_input_as :milk_fat_weight
 
-        next_node do |response|
+        permitted_next_nodes = [
+          :commodity_code_result,
+          :how_much_milk_protein_ab?,
+          :how_much_milk_protein_c?,
+          :how_much_milk_protein_d?,
+          :how_much_milk_protein_ef?,
+          :how_much_milk_protein_gh?
+        ]
+
+        next_node(permitted: permitted_next_nodes) do |response|
           case response.to_i
           when 0, 1
             :how_much_milk_protein_ab?