Clear shipments and payments after failed payment at checkout

app/controllers/checkout_controller.rb

@@ -15,6 +15,10 @@ class CheckoutController < Spree::CheckoutController
   include EnterprisesHelper
 
   def edit
+    # 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
   end
 
   def update
@@ -137,6 +141,7 @@ class CheckoutController < Spree::CheckoutController
 
   def update_failed
     clear_ship_address
+    restart_checkout
     respond_to do |format|
       format.html do
         render :edit
@@ -155,6 +160,14 @@ class CheckoutController < Spree::CheckoutController
     end
   end
 
+  def restart_checkout
+    return if @order.state == 'cart'
+    @order.restart_checkout! # resets state to 'cart'
+    @order.shipments.with_state(:pending).destroy_all
+    @order.payments.with_state(:checkout).destroy_all
+    @order.reload
+  end
+
   def skip_state_validation?
     true
   end

app/models/spree/order_decorator.rb

@@ -376,11 +376,14 @@ Spree::Order.class_eval do
   # object_params sets the payment amount to the order total, but it does this before
   # the shipping method is set. This results in the customer not being charged for their
   # order's shipping. To fix this, we refresh the payment amount here.
-  def charge_shipping!
+  def charge_shipping_and_payment_fees!
     update_totals
     return unless payments.any?
     payments.first.update_attribute :amount, total
   end
 end
 
-Spree::Order.state_machine.after_transition to: :payment, do: :charge_shipping!
+Spree::Order.state_machine.after_transition to: :payment, do: :charge_shipping_and_payment_fees!
+Spree::Order.state_machine.event :restart_checkout do
+  transition :to => :cart, unless: :completed?
+end

spec/requests/checkout/failed_checkout_spec.rb

@@ -0,0 +1,70 @@
+require 'spec_helper'
+
+describe "checking out an order that initially fails", type: :request do
+  include ShopWorkflow
+
+  let!(:shop) { create(:enterprise) }
+  let!(:order_cycle) { create(:simple_order_cycle) }
+  let!(:exchange) { create(:exchange, order_cycle: order_cycle, sender: order_cycle.coordinator, receiver: shop, incoming: false, pickup_time: "Monday") }
+  let!(:address) { create(:address) }
+  let!(:order) { create(:order, distributor: shop, order_cycle: order_cycle) }
+  let!(:line_item) { create(:line_item, order: order, quantity: 3, price: 5.00) }
+  let!(:payment_method) { create(:bogus_payment_method, distributor_ids: [shop.id], environment: Rails.env) }
+  let!(:check_payment_method) { create(:payment_method, distributor_ids: [shop.id], environment: Rails.env) }
+  let!(:shipping_method) { create(:shipping_method, distributor_ids: [shop.id]) }
+  let!(:shipment) { create(:shipment, order: order, shipping_method: shipping_method) }
+  let(:params) do
+    { format: :json, order: {
+      shipping_method_id: shipping_method.id,
+      payments_attributes: [{payment_method_id: payment_method.id}],
+      bill_address_attributes: address.attributes.slice("firstname", "lastname", "address1", "address2", "phone", "city", "zipcode", "state_id", "country_id"),
+      ship_address_attributes: address.attributes.slice("firstname", "lastname", "address1", "address2", "phone", "city", "zipcode", "state_id", "country_id")
+    } }
+  end
+
+  before do
+    order.reload.update_totals
+    set_order order
+  end
+
+  context "when shipping and payment fees apply" do
+    let(:calculator) { Spree::Calculator::FlatPercentItemTotal.new(preferred_flat_percent: 10) }
+
+    before do
+      payment_method.calculator = calculator.dup
+      payment_method.save!
+      check_payment_method.calculator = calculator.dup
+      check_payment_method.save!
+      shipping_method.calculator = calculator.dup
+      shipping_method.save!
+    end
+
+    it "clears shipments and payments before rendering the checkout" do
+      put update_checkout_path, params
+
+      # Checking out a BogusGateway without a source fails at :payment
+      # Shipments and payments should then be cleared before rendering checkout
+      expect(response.status).to be 400
+      expect(flash[:error]).to eq I18n.t(:payment_processing_failed)
+      order.reload
+      expect(order.shipments.count).to be 0
+      expect(order.payments.count).to be 0
+      expect(order.adjustment_total).to eq 0
+
+      # Add another line item to change the fee totals
+      create(:line_item, order: order, quantity: 3, price: 5.00)
+
+      # Use a check payment method, which should work
+      params[:order][:payments_attributes][0][:payment_method_id] = check_payment_method.id
+      put update_checkout_path, params
+
+      expect(response.status).to be 200
+      order.reload
+      expect(order.total).to eq 36
+      expect(order.adjustment_total).to eq 6
+      expect(order.item_total).to eq 30
+      expect(order.shipments.count).to eq 1
+      expect(order.payments.count).to eq 1
+    end
+  end
+end