small refactoring

app/controllers/schemes_controller.rb

@@ -52,20 +52,7 @@ class SchemesController < ApplicationController
           redirect_to scheme_check_answers_path(@scheme)
         end
       else
-        schemes_path = case params[:scheme][:page]
-                       when "primary-client-group"
-                         scheme_confirm_secondary_client_group_path(@scheme)
-                       when "confirm-secondary"
-                         @scheme.has_other_client_group == "Yes" ? scheme_secondary_client_group_path(@scheme) : scheme_support_path(@scheme)
-                       when "secondary-client-group"
-                         scheme_support_path(@scheme)
-                       when "support"
-                         scheme_check_answers_path(@scheme)
-                       when "details"
-                         scheme_primary_client_group_path(@scheme)
-                       end
-
-        redirect_to schemes_path
+        redirect_to derive_next_path params[:scheme][:page]
       end
     else
       render request.current_url, status: :unprocessable_entity
@@ -100,6 +87,21 @@ class SchemesController < ApplicationController
 
   private
 
+  def derive_next_path page
+    case page 
+    when "primary-client-group"
+      scheme_confirm_secondary_client_group_path(@scheme)
+    when "confirm-secondary"
+      @scheme.has_other_client_group == "Yes" ? scheme_secondary_client_group_path(@scheme) : scheme_support_path(@scheme)
+    when "secondary-client-group"
+      scheme_support_path(@scheme)
+    when "support"
+      scheme_check_answers_path(@scheme)
+    when "details"
+      scheme_primary_client_group_path(@scheme)
+    end
+  end
+
   def scheme_params
     required_params = params.require(:scheme).permit(:service_name, :sensitive, :organisation_id, :scheme_type, :registered_under_care_act, :total_units, :id, :has_other_client_group, :primary_client_group, :secondary_client_group, :support_type, :intended_stay)
     required_params[:sensitive] = required_params[:sensitive].to_i if required_params[:sensitive]