Use service in admin/payments#create

This separates logic for bang and non-bang versions of
Spree::Order#next.

The different conditions used in both methods (state == "completed" vs
order.completed?) have implications in whether a transition is attempted
or not.

app/controllers/spree/admin/payments_controller_decorator.rb

@@ -19,10 +19,8 @@ def create
 
          redirect_to admin_order_payments_path(@order)
       else
-        #This is the first payment (admin created order)
-        until @order.completed?
-          @order.next!
-        end
+        AdvanceOrderService.new(@order).call(true)
+
         flash[:success] = Spree.t(:new_order_completed)
         redirect_to edit_admin_order_url(@order)
       end

app/services/advance_order_service.rb

@@ -5,15 +5,31 @@ def initialize(order)
     @order = order
   end
 
-  def call
-    shipping_method_id = @order.shipping_method.id if @order.shipping_method.present?
+  def call(raise_on_error = false)
+    shipping_method_id = order.shipping_method.id if order.shipping_method.present?
+    options = { shipping_method_id: shipping_method_id }
+    raise_on_error ? advance_order!(options) : advance_order(options)
+  end
+
+  private
 
-    while @order.state != "complete"
-      break unless @order.next
+  def advance_order(options)
+    until order.state == "complete"
+      break unless order.next
+      after_transition_hook(options)
+    end
+  end
+
+  def advance_order!(options)
+    until order.completed?
+      order.next!
+      after_transition_hook(options)
+    end
+  end
 
-      if @order.state == "delivery"
-        @order.select_shipping_method(shipping_method_id) if shipping_method_id.present?
-      end
+  def after_transition_hook(options)
+    if order.state == "delivery"
+      order.select_shipping_method(options[:shipping_method_id]) if options[:shipping_method_id]
     end
   end
 end

spec/controllers/spree/admin/payments_controller_spec.rb

@@ -6,9 +6,27 @@
   let!(:order) { create(:order, distributor: shop, state: 'complete') }
   let!(:line_item) { create(:line_item, order: order, price: 5.0) }
 
+  before do
+    allow(controller).to receive(:spree_current_user) { user }
+  end
+
+  context "#create" do
+    let!(:payment_method) { create(:payment_method, distributors: [ shop ]) }
+    let!(:order) do
+      create(:order_with_totals_and_distribution, distributor: shop, state: "payment")
+    end
+
+    let(:params) { { amount: order.total, payment_method_id: payment_method.id } }
+
+    it "advances the order state" do
+      expect {
+        spree_post :create, payment: params, order_id: order.number
+      }.to change { order.reload.state }.from("payment").to("complete")
+    end
+  end
+
   context "as an enterprise user" do
     before do
-      allow(controller).to receive(:spree_current_user) { user }
       order.reload.update_totals
     end