Extract #restart_checkout to a service

app/controllers/checkout_controller.rb

@@ -18,7 +18,7 @@ class CheckoutController < Spree::CheckoutController
     # This is only required because of spree_paypal_express. If we implement
     # a version of paypal that uses this controller, and more specifically
     # the #update_failed method, then we can remove this call
-    restart_checkout
+    RestartCheckout.new(@order).restart_checkout
   end
 
   def update
@@ -139,7 +139,8 @@ class CheckoutController < Spree::CheckoutController
 
   def update_failed
     clear_ship_address
-    restart_checkout
+    RestartCheckout.new(@order).restart_checkout
+
     respond_to do |format|
       format.html do
         render :edit
@@ -159,12 +160,7 @@ class CheckoutController < Spree::CheckoutController
   end
 
   def restart_checkout
-    return if @order.state == 'cart'
-    @order.restart_checkout! # resets state to 'cart'
-    @order.update_attributes!(shipping_method_id: nil)
-    @order.shipments.with_state(:pending).destroy_all
-    @order.payments.with_state(:checkout).destroy_all
-    @order.reload
+    RestartCheckout.new(@order).restart_checkout
   end
 
   def skip_state_validation?

app/services/restart_checkout.rb

@@ -0,0 +1,15 @@
+# Resets the passed order to cart state while clearing associated payments and shipments
+class RestartCheckout
+  def initialize(order)
+    @order = order
+  end
+
+  def restart_checkout
+    return if @order.state == 'cart'
+    @order.restart_checkout! # resets state to 'cart'
+    @order.update_attributes!(shipping_method_id: nil)
+    @order.shipments.with_state(:pending).destroy_all
+    @order.payments.with_state(:checkout).destroy_all
+    @order.reload
+  end
+end

spec/controllers/checkout_controller_spec.rb

@@ -189,11 +189,14 @@ describe CheckoutController, type: :controller do
 
   describe "Paypal routing" do
     let(:payment_method) { create(:payment_method, type: "Spree::Gateway::PayPalExpress") }
+    let(:restart_checkout) { instance_double(RestartCheckout, restart_checkout: true) }
+
     before do
       allow(controller).to receive(:current_distributor) { distributor }
       allow(controller).to receive(:current_order_cycle) { order_cycle }
       allow(controller).to receive(:current_order) { order }
-      allow(controller).to receive(:restart_checkout)
+
+      allow(RestartCheckout).to receive(:new) { restart_checkout }
     end
 
     it "should check the payment method for Paypalness if we've selected one" do
@@ -205,14 +208,20 @@ describe CheckoutController, type: :controller do
   end
 
   describe "#update_failed" do
+    let(:restart_checkout) do
+      instance_double(RestartCheckout, restart_checkout: true)
+    end
+
     before do
       controller.instance_variable_set(:@order, order)
+      allow(RestartCheckout).to receive(:new) { restart_checkout }
     end
 
     it "clears the shipping address and restarts the checkout" do
       expect(controller).to receive(:clear_ship_address)
-      expect(controller).to receive(:restart_checkout)
+      expect(restart_checkout).to receive(:restart_checkout)
       expect(controller).to receive(:respond_to)
+
       controller.send(:update_failed)
     end
   end