Requested changes

- 2 new methods for reading either current/desired on hand/on demand
  depending on variant state. Goal is to get rid of send method in View
- referring in on_hand/on_demand is in fact irrelevant. In the piece of
  code, only desired on_hand/on_demand can be called as we are only in
  new variant (non persisted) mode
- View does not use send method anymore, replaced by current_or_desired
- refactor of the spec -> 2 examples in one to get more speed.

app/models/concerns/variant_stock.rb

@@ -77,6 +77,18 @@ def on_demand=(new_value)
     end
   end
 
+  def on_demand_desired_or_current
+    return on_demand_desired if new_record?
+
+    on_demand
+  end
+
+  def on_hand_desired_or_current
+    return on_hand_desired if new_record?
+
+    on_hand
+  end
+
   # Moving Spree::Stock::Quantifier.can_supply? to the variant enables us
   #   to override this behaviour for variant overrides
   # We can have this responsibility here in the variant because there is

app/services/sets/product_set.rb

@@ -131,7 +131,11 @@ def create_variant(product, variant_attributes)
       return variant if variant.errors.present?
 
       begin
-        create_stock_for_variant(variant, on_demand, on_hand)
+        if on_hand || on_demand
+          create_stock_for_variant(variant, on_demand, on_hand)
+        else
+          create_stock_for_variant_from_desired(variant)
+        end
       rescue StandardError => e
         notify_bugsnag(e, product, variant, variant_attributes)
         raise e
@@ -156,8 +160,11 @@ def notify_bugsnag(error, product, variant, variant_attributes)
 
     def create_stock_for_variant(variant, on_demand, on_hand)
       variant.on_demand = on_demand if on_demand.present?
-      variant.on_demand = variant.on_demand_desired if variant.on_demand_desired.present?
       variant.on_hand = on_hand.to_i if on_hand.present?
+    end
+
+    def create_stock_for_variant_from_desired(variant)
+      variant.on_demand = variant.on_demand_desired if variant.on_demand_desired.present?
       variant.on_hand = variant.on_hand_desired.to_i if variant.on_hand_desired.present?
     end
   end

app/views/admin/products_v3/_variant_row.html.haml

@@ -31,10 +31,10 @@
   = error_message_on variant, :price
 %td.col-on_hand.field.popout{'data-controller': "popout"}
   %button.popout__button{'data-popout-target': "button", 'aria-label': t('admin.products_page.columns.on_hand')}
-    = variant.send(method_on_demand) ? t(:on_demand) : variant.send(method_on_hand)
+    = variant.on_demand_desired_or_current ? t(:on_demand) : variant.on_hand_desired_or_current
   %div.popout__container{ style: 'display: none;', 'data-controller': 'toggle-control', 'data-popout-target': "dialog" }
     .field
-      = f.number_field method_on_hand, min: 0, 'aria-label': t('admin.products_page.columns.on_hand'), 'data-toggle-control-target': 'control', disabled: f.object.send(method_on_demand)
+      = f.number_field method_on_hand, min: 0, 'aria-label': t('admin.products_page.columns.on_hand'), 'data-toggle-control-target': 'control', disabled: f.object.on_demand_desired_or_current
       = error_message_on variant, method_on_hand
     .field.checkbox
       = f.label method_on_demand do

spec/system/admin/products_v3/products_spec.rb

@@ -934,7 +934,7 @@ def expect_other_columns_visible
         click_on "New variant"
       end
 
-      it 'displays the correct value afterwards for On Hand' do
+      it 'displays the correct value afterwards both for On Hand & On demand' do
         within new_variant_row do
           fill_in "Name", with: "Large box"
           click_on "On Hand"
@@ -947,11 +947,8 @@ def expect_other_columns_visible
         within row_containing_name("Large box") do
           expect(page).to have_content "19"
         end
-      end
 
-      it 'displays the correct value afterwards for On demand' do
-        within new_variant_row do
-          fill_in "Name", with: "Large box"
+        within row_containing_name("Large box") do
           click_on "On Hand"
           check "On demand"
         end