Merge pull request #2908 from nebulab/fix_fullfilment_charger_allocation

Spree::FulfilmentChanger stock allocation fix

core/app/models/spree/fulfilment_changer.rb

@@ -46,7 +46,7 @@ def run!
       desired_shipment.save! if desired_shipment.new_record?
 
       # Retrieve how many on hand items we can take from desired stock location
-      available_quantity = [desired_shipment.stock_location.count_on_hand(variant), 0].max
+      available_quantity = [desired_shipment.stock_location.count_on_hand(variant), default_on_hand_quantity].max
 
       new_on_hand_quantity = [available_quantity, quantity].min
       unstock_quantity = desired_shipment.stock_location.backorderable?(variant) ? quantity : new_on_hand_quantity
@@ -114,6 +114,14 @@ def handle_stock_counts?
       current_shipment.order.completed? && current_stock_location != desired_stock_location
     end
 
+    def default_on_hand_quantity
+      if current_stock_location != desired_stock_location
+        0
+      else
+        current_shipment.inventory_units.where(variant: variant).on_hand.count
+      end
+    end
+
     def current_shipment_not_already_shipped
       if current_shipment.shipped?
         errors.add(:current_shipment, :has_already_been_shipped)

core/spec/models/spree/fulfilment_changer_spec.rb

@@ -37,6 +37,39 @@
     variant.stock_items.first.update_column(:count_on_hand, 100)
   end
 
+  context "when the current shipment stock location is the same of the target shipment" do
+    let(:current_shipment_inventory_unit_count) { 1 }
+    let(:quantity) { current_shipment_inventory_unit_count }
+
+    context "when the stock location is empty" do
+      before do
+        variant.stock_items.first.update_column(:count_on_hand, 0)
+      end
+
+      context "when the inventory unit is backordered" do
+        before do
+          current_shipment.inventory_units.first.update state: :backordered
+        end
+
+        it "creates a new backordered inventory unit" do
+          subject
+          expect(desired_shipment.inventory_units.first).to be_backordered
+        end
+      end
+
+      context "when the inventory unit is on hand" do
+        before do
+          current_shipment.inventory_units.first.update state: :on_hand
+        end
+
+        it "creates a new on hand inventory unit" do
+          subject
+          expect(desired_shipment.inventory_units.first).to be_on_hand
+        end
+      end
+    end
+  end
+
   context "when the current shipment has enough inventory units" do
     let(:current_shipment_inventory_unit_count) { 2 }
     let(:quantity) { 1 }