Extract order-updating logic to Order::Updater

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