Add confirm event and update workflow helpers

app/models/spree/order/checkout.rb

@@ -67,6 +67,10 @@ module Spree
                 transition to: :cart, unless: :completed?
               end
 
+              event :confirm do
+                transition to: :complete, from: :confirmation
+              end
+
               before_transition from: :cart, do: :ensure_line_items_present
 
               before_transition to: :delivery, do: :create_proposed_shipments

app/services/order_workflow.rb

@@ -27,6 +27,10 @@ class OrderWorkflow
     advance_to_state("payment", advance_order_options)
   end
 
+  def advance_to_confirmation
+    advance_to_state("confirmation", advance_order_options)
+  end
+
   private
 
   def advance_order_options