Hide remove item button when item not possible to remove

This change applies to Sales Panel.
A similar change is needed in the Client Panel.

Tested this via integration test and checking if remove url
is visible or not in different states.
This doesn't test the Turbo mechanism which is used here too.

I don't like this duplication between the Rails view button and the same in Turbo call. I suppose we should be less granular and just rerender whole table here instead of single values.

Another ugly place is now this if/else in the view. Hard to avoid it, but maybe once we move this view to Ruby code, it can be better structured (plan for the future).

rails_application/app/read_models/orders/add_item_to_order.rb

@@ -1,5 +1,9 @@
 module Orders
   class AddItemToOrder < Infra::EventHandler
+    include Rails.application.routes.url_helpers
+    include ActionView::Helpers::UrlHelper
+    include ActionView::Helpers::FormTagHelper
+
     def call(event)
       order_id = event.data.fetch(:order_id)
       ApplicationRecord.with_advisory_lock(order_id) do
@@ -13,6 +17,7 @@ def call(event)
 
         broadcaster.call(order_id, product_id, "quantity", item.quantity)
         broadcaster.call(order_id, product_id, "value", ActiveSupport::NumberHelper.number_to_currency(item.value))
+        broadcaster.call(order_id, product_id, "remove_item_button", button_to("Remove", remove_item_order_path(id: order_id, product_id: product_id), class: "hover:underline text-blue-500"))
       end
 
       event_store.link_event_to_stream(event, "Orders$all")

rails_application/app/read_models/orders/remove_item_from_order.rb

@@ -9,6 +9,7 @@ def call(event)
 
       broadcaster.call(order_id, product_id, "quantity", item.quantity)
       broadcaster.call(order_id, product_id, "value", ActiveSupport::NumberHelper.number_to_currency(item.value))
+      broadcaster.call(order_id, product_id, "remove_item_button", "") if item.quantity.zero?
 
       event_store.link_event_to_stream(event, "Orders$all")
     end

rails_application/app/views/orders/edit.html.erb

@@ -44,8 +44,12 @@
       <td class="py-2" id="<%= "orders_order_#{product.id}_quantity" %>"><%= order_line.try(&:quantity) || 0 %></td>
       <td class="py-2"><%= number_to_currency(product.price) %></td>
       <td class="py-2" id="<%= "orders_order_#{product.id}_value" %>"><%= number_to_currency(order_line.try(&:value)) %></td>
-      <td class="py-2 text-right"><%= button_to "Add", add_item_order_path(id: @order_id, product_id: product.id), class: "hover:underline text-blue-500" %></td>
-      <td class="py-2 text-right"><%= button_to "Remove", remove_item_order_path(id: @order_id, product_id: product.id), class: "hover:underline text-blue-500" %></td>
+      <td class="py-2"><%= button_to "Add", add_item_order_path(id: @order_id, product_id: product.id), class: "hover:underline text-blue-500" %></td>
+      <% if order_line.nil? %>
+        <td class="py-2 text-right" id="<%= "orders_order_#{product.id}_remove_item_button" %>"></td>
+      <%  else %>
+        <td class="py-2 text-right" id="<%= "orders_order_#{product.id}_remove_item_button" %>"><%=  button_to("Remove", remove_item_order_path(id: @order_id, product_id: product.id), class: "hover:underline text-blue-500") %></td>
+        <% end %>
     </tr>
   <% end %>
   </tbody>

rails_application/test/integration/orders_test.rb

@@ -47,10 +47,16 @@ def test_happy_path
 
     get "/"
     get "/orders/new"
+    follow_redirect!
+
+    assert_remove_buttons_not_visible(async_remote_id, fearless_id)
+
     post "/orders/#{order_id}/add_item?product_id=#{async_remote_id}"
     post "/orders/#{order_id}/add_item?product_id=#{fearless_id}"
     post "/orders/#{order_id}/add_item?product_id=#{fearless_id}"
     Sidekiq::Job.drain_all
+    get "/orders/#{order_id}/edit"
+    assert_remove_buttons_visible(async_remote_id, fearless_id, order_id)
 
     apply_discount_10_percent(order_id)
     Sidekiq::Job.drain_all
@@ -224,6 +230,22 @@ def test_discount_is_applied_for_new_order
 
   private
 
+  def assert_remove_buttons_visible(async_remote_id, fearless_id, order_id)
+    assert_match(/#{Regexp.escape(remove_item_order_path(id: order_id, product_id: async_remote_id))}/, response.body)
+    assert_match(/#{Regexp.escape(remove_item_order_path(id: order_id, product_id: fearless_id))}/, response.body)
+  end
+
+  def assert_remove_buttons_not_visible(async_remote_id, fearless_id)
+    url = request.original_url
+    uri = URI.parse(url)
+    puts uri.query
+    path_components = uri.path.split('/')
+    order_uuid = path_components[-2]
+
+    assert_no_match(/#{Regexp.escape(remove_item_order_path(id: order_uuid, product_id: async_remote_id))}/, response.body)
+    assert_no_match(/#{Regexp.escape(remove_item_order_path(id: order_uuid, product_id: fearless_id))}/, response.body)
+  end
+
   def verify_shipping(order_id)
     get "/orders/#{order_id}"
     assert_select("dd", "Shipping address is missing.")