Perform variant override scoping on product/variant by external class. Centralise this so we can load everything in one go.

app/models/spree/inventory_unit_decorator.rb

@@ -4,9 +4,10 @@ module Spree
       return [] unless order.completed?
 
       #increase inventory to meet initial requirements
+      scoper = OpenFoodNetwork::ScopeVariantToHub.new(order.distributor)
       order.line_items.each do |line_item|
         # Scope variant to hub so that stock levels may be subtracted from VariantOverride.
-        line_item.variant.scope_to_hub order.distributor
+        scoper.scope(line_item.variant)
 
         increase(order, line_item.variant, line_item.quantity)
       end

app/models/spree/order_populator_decorator.rb

@@ -9,7 +9,7 @@ Spree::OrderPopulator.class_eval do
       errors.add(:base, "That distributor or order cycle can't supply all the products in your cart. Please choose another.")
     end
 
-    if valid? 
+    if valid?
       @order.with_lock do
         @order.empty! if overwrite
 
@@ -33,7 +33,7 @@ Spree::OrderPopulator.class_eval do
   def attempt_cart_add(variant_id, quantity, max_quantity = nil)
     quantity = quantity.to_i
     variant = Spree::Variant.find(variant_id)
-    variant.scope_to_hub @distributor
+    OpenFoodNetwork::ScopeVariantToHub.new(@distributor).scope(variant)
     if quantity > 0
       if check_stock_levels(variant, quantity) &&
           check_order_cycle_provided_for(variant) &&

app/models/spree/product_decorator.rb

@@ -1,8 +1,4 @@
-require 'open_food_network/scope_product_to_hub'
-
 Spree::Product.class_eval do
-  include OpenFoodNetwork::ProductScopableToHub
-
   # We have an after_destroy callback on Spree::ProductOptionType. However, if we
   # don't specify dependent => destroy on this association, it is not called. See:
   # https://github.com/rails/rails/issues/7618

app/models/spree/variant_decorator.rb

@@ -1,10 +1,7 @@
-require 'open_food_network/scope_variant_to_hub'
 require 'open_food_network/enterprise_fee_calculator'
 require 'open_food_network/option_value_namer'
 
 Spree::Variant.class_eval do
-  include OpenFoodNetwork::VariantScopableToHub
-
   has_many :exchange_variants, dependent: :destroy
   has_many :exchanges, through: :exchange_variants
   has_many :variant_overrides