Merge pull request #2199 from jhawthorn/simple_stock_coordinator

Replace Stock::Coordinator with Stock::SimpleCoordinator

api/spec/requests/spree/api/orders_controller_spec.rb

@@ -506,6 +506,7 @@ module Spree
 
       context "with a line item" do
         let(:order) { create(:order_with_line_items) }
+        let(:line_item) { order.line_items.first }
 
         it "can empty an order" do
           create(:adjustment, order: order, adjustable: order)

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

@@ -0,0 +1,70 @@
+module Spree
+  module Stock
+    # This class manages checking stock availability efficiently for a set of
+    # Variants and StockLocations.
+    #
+    # This serves a similar role to Spree::Stock::Quantifier, but is more
+    # efficient by checking multiple variants at once.
+    class Availability
+      # @param variants [Array<Spree::Variant>] variants to check stock of
+      # @param stock_locations [Array<Spree::StockLocation>] stock_locations to check for stock in
+      def initialize(variants:, stock_locations: Spree::StockLocation.active)
+        @variants = variants
+        @variant_map = variants.index_by(&:id)
+        @stock_locations = stock_locations
+      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 on_hand_by_stock_location_id
+        counts_on_hand.to_a.group_by do |(_, stock_location_id), _|
+          stock_location_id
+        end.transform_values do |values|
+          Spree::StockQuantities.new(
+            values.map do |(variant_id, _), count|
+              variant = @variant_map[variant_id]
+              count = Float::INFINITY if !variant.should_track_inventory?
+              count = 0 if count < 0
+              [variant, count]
+            end.to_h
+          )
+        end
+      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|
+          Spree::StockQuantities.new(
+            variant_ids.map do |variant_id, _|
+              variant = @variant_map[variant_id]
+              [variant, Float::INFINITY]
+            end.to_h
+          )
+        end
+      end
+
+      private
+
+      def counts_on_hand
+        @counts_on_hand ||=
+          stock_item_scope.
+            group(:variant_id, :stock_location_id).
+            sum(:count_on_hand)
+      end
+
+      def backorderables
+        @backorderables ||=
+          stock_item_scope.
+            where(backorderable: true).
+            pluck(:variant_id, :stock_location_id)
+      end
+
+      def stock_item_scope
+        Spree::StockItem.
+          where(variant_id: @variants).
+          where(stock_location_id: @stock_locations)
+      end
+    end
+  end
+end