When cart is updated with insufficient stock, show amount in cart, not amount entered

app/controllers/spree/orders_controller_decorator.rb

@@ -16,6 +16,7 @@ Spree::OrdersController.class_eval do
   # Patching to redirect to shop if order is empty
   def edit
     @order = current_order(true)
+    @insufficient_stock_lines = @order.insufficient_stock_lines
 
     if @order.line_items.empty?
       redirect_to main_app.shop_path
@@ -28,6 +29,41 @@ Spree::OrdersController.class_eval do
     end
   end
 
+
+  def update
+    @insufficient_stock_lines = []
+    @order = current_order
+    unless @order
+      flash[:error] = t(:order_not_found)
+      redirect_to root_path and return
+    end
+
+    if @order.update_attributes(params[:order])
+      @order.line_items = @order.line_items.select {|li| li.quantity > 0 }
+      @order.restart_checkout_flow
+
+      render :edit and return unless apply_coupon_code
+
+      fire_event('spree.order.contents_changed')
+      respond_with(@order) do |format|
+        format.html do
+          if params.has_key?(:checkout)
+            @order.next_transition.run_callbacks if @order.cart?
+            redirect_to checkout_state_path(@order.checkout_steps.first)
+          else
+            redirect_to cart_path
+          end
+        end
+      end
+    else
+      # Show order with original values, not newly entered ones
+      @insufficient_stock_lines = @order.insufficient_stock_lines
+      @order.line_items(true)
+      respond_with(@order)
+    end
+  end
+
+
   def populate
     # Without intervention, the Spree::Adjustment#update_adjustable callback is called many times
     # during cart population, for both taxation and enterprise fees. This operation triggers a
@@ -55,6 +91,7 @@ Spree::OrdersController.class_eval do
     end
   end
 
+
   # Report the stock levels in the order for all variant ids requested
   def stock_levels(order, variant_ids)
     stock_levels = li_stock_levels(order)

app/views/spree/orders/_line_item.html.haml

@@ -17,7 +17,7 @@
 
     = render 'spree/shared/line_item_name', line_item: line_item
 
-    - if @order.insufficient_stock_lines.include? line_item
+    - if @insufficient_stock_lines.include? line_item
       %span.out-of-stock
         = variant.in_stock? ? t(:insufficient_stock, :on_hand => variant.on_hand) : t(:out_of_stock)
         %br/

spec/features/consumer/shopping/cart_spec.rb

@@ -7,25 +7,45 @@ feature "full-page cart", js: true do
   include UIComponentHelper
 
   describe "viewing the cart" do
+    let!(:zone) { create(:zone_with_member) }
+    let(:distributor) { create(:distributor_enterprise, with_payment_and_shipping: true, charges_sales_tax: true) }
+    let(:supplier) { create(:supplier_enterprise) }
+    let!(:order_cycle) { create(:simple_order_cycle, suppliers: [supplier], distributors: [distributor], coordinator: create(:distributor_enterprise), variants: [product.variants.first]) }
+    let(:enterprise_fee) { create(:enterprise_fee, amount: 11.00, tax_category: product.tax_category) }
+    let(:product) { create(:taxed_product, supplier: supplier, zone: zone, price: 110.00, tax_rate_amount: 0.1) }
+    let(:variant) { product.variants.first }
+    let(:order) { create(:order, order_cycle: order_cycle, distributor: distributor) }
+
+    before do
+      add_enterprise_fee enterprise_fee
+      set_order order
+      add_product_to_cart
+      visit spree.cart_path
+    end
+
     describe "tax" do
-      let!(:zone) { create(:zone_with_member) }
-      let(:distributor) { create(:distributor_enterprise, with_payment_and_shipping: true, charges_sales_tax: true) }
-      let(:supplier) { create(:supplier_enterprise) }
-      let!(:order_cycle) { create(:simple_order_cycle, suppliers: [supplier], distributors: [distributor], coordinator: create(:distributor_enterprise), variants: [product.variants.first]) }
-      let(:enterprise_fee) { create(:enterprise_fee, amount: 11.00, tax_category: product.tax_category) }
-      let(:product) { create(:taxed_product, supplier: supplier, zone: zone, price: 110.00, tax_rate_amount: 0.1) }
-      let(:order) { create(:order, order_cycle: order_cycle, distributor: distributor) }
-
-      before do
-        add_enterprise_fee enterprise_fee
-        set_order order
-        add_product_to_cart
-        visit spree.cart_path
-      end
-
       it "shows the total tax for the order, including product tax and tax on fees" do
         page.should have_selector '.tax-total', text: '11.00' # 10 + 1
       end
     end
+
+    describe "updating quantities with insufficient stock available" do
+      let(:li) { order.line_items(true).last }
+
+      use_short_wait 10
+
+      before do
+        variant.update_attributes! on_hand: 2
+      end
+
+      it "shows the quantities saved, not those submitted" do
+        fill_in "order_line_items_attributes_0_quantity", with: '4'
+
+        click_button 'Update'
+
+        page.should have_field "order[line_items_attributes][0][quantity]", with: '1'
+        page.should have_content "Insufficient stock available, only 2 remaining"
+      end
+    end
   end
 end