Marketplace: Checkout is prevented without a DeliveryArea

- #1983

Prevents `Shoppers` from visiting the `Checkout` screen until a
`DeliveryArea` has been selected.

app/furniture/marketplace/cart.rb

@@ -54,7 +54,7 @@ def price_total
     end
 
     def ready_for_checkout?
-      delivery.details_filled_in? && cart_products.present? && cart_products.all?(&:valid?)
+      delivery_area.present? && cart_products.present? && cart_products.all?(&:valid?)
     end
   end
 end

app/furniture/marketplace/carts/_footer.html.erb

@@ -12,7 +12,7 @@
   </tr>
   <tr>
     <td class="text-right py-3.5" colspan="8">
-      <%= render ButtonComponent.new(label: "Checkout", href: cart.location(child: :checkout), scheme: :primary, method: :get) %>
+      <%= render ButtonComponent.new(label: "Checkout", href: cart.location(child: :checkout), scheme: :primary, method: :get, disabled: !cart.ready_for_checkout?) %>
     </td>
   </tr>
 </tfoot>

spec/furniture/marketplace/buying_products_system_spec.rb

@@ -24,6 +24,18 @@ def url_options
     {host: server_uri.host, port: server_uri.port}
   end
 
+  context "when there is not a DeliveryArea selected" do
+    it "Prevents Checkout unless a DeliveryArea is selected" do
+      create(:marketplace_delivery_area, marketplace: marketplace)
+
+      visit(polymorphic_path(marketplace.room.location))
+
+      add_product_to_cart(marketplace.products.first)
+
+      expect { click_link("Checkout") }.to raise_error(Capybara::ElementNotFound)
+    end
+  end
+
   it "Works for Guests" do # rubocop:disable RSpec/ExampleLength
     visit(polymorphic_path(marketplace.room.location))