Autoremove/update item from the cart if stock changed during checkout

app/assets/javascripts/templates/out_of_stock.html.haml

@@ -1,3 +1,4 @@
+// please update the modal html in app/view/checkout/edit.html.haml if updating this template
 %a.close-reveal-modal{"ng-click" => "$close()"}
   %i.ofn-i_009-close
 

app/controllers/checkout_controller.rb

@@ -26,6 +26,7 @@ def edit
     if params[:step].blank?
       redirect_to_step_based_on_order
     else
+      handle_insufficient_stock if details_step?
       update_order_state
       check_step
     end
@@ -36,6 +37,9 @@ def edit
   end
 
   def update
+    return render cable_ready: cable_car.redirect_to(url: checkout_step_path(:details)) \
+      unless sufficient_stock?
+
     if confirm_order || update_order
       return if performed?
 
@@ -152,6 +156,7 @@ def order_params
   # state. We need to do this when moving back to a previous checkout step, the update action takes
   # care of moving the order state forward.
   def update_order_state
+    # debugger
     return @order.back_to_payment if @order.confirmation? && payment_step?
 
     return unless @order.after_delivery_state? && details_step?

app/controllers/concerns/checkout_callbacks.rb

@@ -25,7 +25,6 @@ module CheckoutCallbacks
 
     before_action :ensure_order_not_completed
     before_action :ensure_checkout_allowed
-    before_action :handle_insufficient_stock
     before_action :check_authorization
   end
 

app/controllers/concerns/order_stock_check.rb

@@ -4,17 +4,20 @@ module OrderStockCheck
   include CablecarResponses
   extend ActiveSupport::Concern
 
+  delegate :sufficient_stock?, to: :check_stock_service
+
   def valid_order_line_items?
-    @order.insufficient_stock_lines.empty? &&
-      OrderCycles::DistributedVariantsService.new(@order.order_cycle, @order.distributor).
-        distributes_order_variants?(@order)
+    OrderCycles::DistributedVariantsService.new(@order.order_cycle, @order.distributor).
+      distributes_order_variants?(@order)
   end
 
   def handle_insufficient_stock
+    @any_out_of_stock = false
+
     return if sufficient_stock?
 
-    flash[:error] = Spree.t(:inventory_error_flash_for_insufficient_quantity)
-    redirect_to main_app.cart_path
+    @any_out_of_stock = true
+    @updated_variants = check_stock_service.update_line_items
   end
 
   def check_order_cycle_expiry
@@ -36,7 +39,7 @@ def check_order_cycle_expiry
 
   private
 
-  def sufficient_stock?
-    @sufficient_stock ||= @order.insufficient_stock_lines.blank?
+  def check_stock_service
+    @check_stock_service ||= Orders::CheckStockService.new(order: @order)
   end
 end

app/controllers/payment_gateways/paypal_controller.rb

@@ -14,6 +14,8 @@ class PaypalController < ::BaseController
     after_action :reset_order_when_complete, only: :confirm
 
     def express
+      return redirect_to order_failed_route if @any_out_of_stock == true
+
       pp_request = provider.build_set_express_checkout(
         express_checkout_request_details(@order)
       )
@@ -41,6 +43,8 @@ def express
     end
 
     def confirm
+      return redirect_to order_failed_route if @any_out_of_stock == true
+
       # At this point the user has come back from the Paypal form, and we get one
       # last chance to interact with the payment process before the money moves...
 

app/controllers/payment_gateways/stripe_controller.rb

@@ -8,9 +8,12 @@ class StripeController < BaseController
     before_action :load_checkout_order, only: :confirm
     before_action :validate_payment_intent, only: :confirm
     before_action :check_order_cycle_expiry, only: :confirm
-    before_action :validate_stock, only: :confirm
 
     def confirm
+      validate_stock
+
+      return redirect_to order_failed_route if @any_out_of_stock == true
+
       process_payment_completion!
     end
 

app/services/orders/check_stock_service.rb

@@ -0,0 +1,27 @@
+# frozen_string_literal: true
+
+module Orders
+  class CheckStockService
+    attr_reader :order
+
+    def initialize(order:)
+      @order = order
+    end
+
+    def sufficient_stock?
+      @sufficient_stock ||= order.insufficient_stock_lines.blank?
+    end
+
+    def update_line_items
+      return [] if sufficient_stock?
+
+      variants = []
+      order.insufficient_stock_lines.each do |line_item|
+        order.contents.update_item(line_item, { quantity: line_item.variant.on_hand })
+        variants.push line_item.variant
+      end
+
+      variants
+    end
+  end
+end

app/views/checkout/edit.html.haml

@@ -20,6 +20,29 @@
     = render partial: "shopping_shared/order_cycles"
 
   %div{ "data-controller": "guest-checkout", "data-guest-checkout-distributor-value": @order.distributor.id }
+    - if @any_out_of_stock
+      = render ModalComponent.new(id: "out-of-stock-items", modal_class: "medium" ,instant: true, close_button: false) do
+        - # please update app/assets/javascripts/templates/out_of_stock.html.haml if updating the modal html
+        %a.close-reveal-modal{"data-action": "click->modal#close" }
+          %i.ofn-i_009-close
+        %h3
+          = t("js.out_of_stock.reduced_stock_available")
+        %p
+          = t("js.out_of_stock.out_of_stock_text")
+        - @updated_variants.each do |variant|
+          - if variant.on_hand == 0
+            %p
+              %em
+                = "#{variant.name_to_display} - #{variant.unit_to_display}"
+                %span
+                  = t("js.out_of_stock.now_out_of_stock")
+          - if variant.on_hand > 0
+            %p
+              %em
+                = "#{variant.name_to_display} - #{variant.unit_to_display}"
+                %span
+                  = t("js.out_of_stock.only_n_remainging", num: variant.on_hand)
+
     %div{ style: "display: #{spree_current_user ? 'block' : 'none'}", "data-guest-checkout-target": "checkout" }
       = render partial: "checkout"
 

spec/controllers/checkout_controller_spec.rb

@@ -144,6 +144,17 @@
           expect(order.reload.state).to eq "payment"
         end
 
+        context "with insufficient stock" do
+          it "redirects to details page" do
+            allow(order).to receive_message_chain(:insufficient_stock_lines,
+                                                  :empty?).and_return false
+
+            put(:update, params:)
+
+            expect_cable_ready_redirect(response)
+          end
+        end
+
         describe "saving default addresses" do
           it "doesn't update default bill address on user" do
             expect {
@@ -306,6 +317,17 @@
             expect(response).to redirect_to checkout_step_path(:summary)
           end
         end
+
+        context "with insufficient stock" do
+          it "redirects to details page" do
+            allow(order).to receive_message_chain(:insufficient_stock_lines,
+                                                  :empty?).and_return false
+
+            put(:update, params:)
+
+            expect_cable_ready_redirect(response)
+          end
+        end
       end
 
       context "with no payment source" do
@@ -468,6 +490,16 @@
         end
       end
 
+      context "with insufficient stock" do
+        it "redirects to details page" do
+          allow(order).to receive_message_chain(:insufficient_stock_lines, :empty?).and_return false
+
+          put(:update, params:)
+
+          expect_cable_ready_redirect(response)
+        end
+      end
+
       context "when accepting T&Cs is required" do
         before do
           allow(TermsOfService).to receive(:platform_terms_required?) { true }
@@ -582,17 +614,10 @@
       )
     end
 
-    shared_examples "handling stock issues" do |step|
+    shared_examples "handling not available items" do |step|
       context "#{step} step" do
         let(:step) { step.to_s }
 
-        it "redirects when some items are out of stock" do
-          allow(order).to receive_message_chain(:insufficient_stock_lines, :empty?).and_return false
-
-          get :edit
-          expect(response).to redirect_to cart_path
-        end
-
         it "redirects when some items are not available" do
           allow(order).to receive_message_chain(:insufficient_stock_lines, :empty?).and_return true
           expect(order_cycle_distributed_variants).to receive(
@@ -605,9 +630,9 @@
       end
     end
 
-    it_behaves_like "handling stock issues", "details"
-    it_behaves_like "handling stock issues", "payment"
-    it_behaves_like "handling stock issues", "summary"
+    it_behaves_like "handling not available items", "details"
+    it_behaves_like "handling not available items", "payment"
+    it_behaves_like "handling not available items", "summary"
   end
 
   def mock_voucher_adjustment_service
@@ -616,4 +641,10 @@ def mock_voucher_adjustment_service
 
     voucher_adjustment_service
   end
+
+  def expect_cable_ready_redirect(response)
+    expect(response.parsed_body).to eq(
+      [{ "url" => "/checkout/details", "operation" => "redirectTo" }].to_json
+    )
+  end
 end