Fix solidus stock locations sorting

The order of the stock locations that is returned from the configured
sorter is lost in the SimpleCoordinator. This occurs in
the Stock::Availiability class when creating the #stock_item_scope.

Previously, the now unused and unusable #sort_availability
method was used to re-order the stock locations but this was
lost during the refactor to allow extending the default Solidus
allocation logic.

This commit re-orders the stock locations for all methods
called by the stock allocators.

core/app/models/spree/stock/availability.rb

@@ -19,7 +19,7 @@ def initialize(variants:, stock_locations: Spree::StockLocation.active)
       # Get the on_hand stock quantities
       # @return [Hash<Integer=>Spree::StockQuantities>] A map of stock_location_ids to the stock quantities available in that location
       def on_hand_by_stock_location_id
-        counts_on_hand.to_a.group_by do |(_, stock_location_id), _|
+        on_hand_quantities = counts_on_hand.to_a.group_by do |(_, stock_location_id), _|
           stock_location_id
         end.transform_values do |values|
           Spree::StockQuantities.new(
@@ -31,19 +31,21 @@ def on_hand_by_stock_location_id
             end.to_h
           )
         end
+        stock_location_sorter(on_hand_quantities)
       end
 
       # Get the on_hand stock quantities
       # @return [Hash<Integer=>Spree::StockQuantities>] A map of stock_location_ids to the stock quantities available in that location
       def backorderable_by_stock_location_id
-        backorderables.group_by(&:second).transform_values do |variant_ids|
+        backorderable_quantities = backorderables.group_by(&:second).transform_values do |variant_ids|
           Spree::StockQuantities.new(
             variant_ids.map do |variant_id, _|
               variant = @variant_map[variant_id]
               [variant, Float::INFINITY]
             end.to_h
           )
         end
+        stock_location_sorter(backorderable_quantities)
       end
 
       private
@@ -67,6 +69,12 @@ def stock_item_scope
           where(variant_id: @variants).
           where(stock_location_id: @stock_locations)
       end
+
+      def stock_location_sorter(stock_quantities)
+        location_ids = @stock_locations.map(&:id)
+
+        stock_quantities.sort_by { |stock_quantity| location_ids.index(stock_quantity[0]) }.to_h
+      end
     end
   end
 end

core/app/models/spree/stock/simple_coordinator.rb

@@ -87,16 +87,6 @@ def split_packages(initial_packages)
         end
       end
 
-      def sort_availability(availability)
-        sorted_availability = availability.sort_by do |stock_location_id, _|
-          @stock_locations.find_index do |stock_location|
-            stock_location.id == stock_location_id
-          end
-        end
-
-        Hash[sorted_availability]
-      end
-
       def get_units(quantities)
         # Change our raw quantities back into inventory units
         quantities.flat_map do |variant, quantity|