Extract order-updating logic to Order::Updater

app/models/spree/payment.rb

@@ -201,19 +201,7 @@ module Spree
     end
 
     def update_order
-      if completed? || void?
-        order.updater.update_payment_total
-      end
-
-      if order.completed?
-        order.updater.update_payment_state
-        order.updater.update_shipments
-        order.updater.update_shipment_state
-      end
-
-      if self.completed? || order.completed?
-        order.updater.persist_totals
-      end
+      OrderManagement::Order::Updater.new(order).after_payment_update(self)
     end
 
     # Necessary because some payment gateways will refuse payments with

engines/order_management/app/services/order_management/order/updater.rb

@@ -141,6 +141,22 @@ module OrderManagement
         order.ship_address = order.address_from_distributor
       end
 
+      def after_payment_update(payment)
+        if payment.completed? || payment.void?
+          update_payment_total
+        end
+
+        if order.completed?
+          update_payment_state
+          update_shipments
+          update_shipment_state
+        end
+
+        if payment.completed? || order.completed?
+          persist_totals
+        end
+      end
+
       private
 
       def round_money(value)

spec/models/spree/payment_spec.rb

@@ -556,11 +556,19 @@ describe Spree::Payment do
       end
 
       context "completed orders" do
+        let(:order_updater) { OrderManagement::Order::Updater.new(order) }
+
         before { allow(order).to receive(:completed?) { true } }
 
         it "updates payment_state and shipments" do
-          expect(order.updater).to receive(:update_payment_state)
-          expect(order.updater).to receive(:update_shipment_state)
+          expect(OrderManagement::Order::Updater).to receive(:new).with(order).
+            and_return(order_updater)
+
+          expect(order_updater).to receive(:after_payment_update).with(kind_of(Spree::Payment)).
+            and_call_original
+
+          expect(order_updater).to receive(:update_payment_state)
+          expect(order_updater).to receive(:update_shipment_state)
           create(:payment, amount: 100, order: order)
         end
       end