Make Splitter::Base.build_package and Shipment.to_package use Config::package_factory

core/app/models/spree/shipment.rb

@@ -222,7 +222,7 @@ def inventory_units_for(variant)
     end
 
     def to_package
-      package = Stock::Package.new(stock_location, order)
+      package = Spree::Config.package_factory.new(stock_location, order)
       inventory_units.includes(:variant).each do |inventory_unit|
         package.add inventory_unit.variant, 1, inventory_unit.state_name
       end

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

@@ -1,7 +1,7 @@
 module Spree
   module Stock
     class Packer
-      attr_reader :stock_location, :order, :splitters
+      attr_reader :stock_location, :order, :splitters, :package_factory
 
       def initialize(stock_location, order, splitters=[Splitter::Base])
         @stock_location = stock_location
@@ -28,8 +28,6 @@ def default_package
 
       private
 
-      attr_reader :package_factory
-
       def build_splitter
         splitter = nil
         splitters.reverse.each do |klass|

core/app/models/spree/stock/splitter/base.rb

@@ -15,12 +15,13 @@ def split(packages)
         end
 
         private
+
         def return_next(packages)
           next_splitter ? next_splitter.split(packages) : packages
         end
 
         def build_package(contents=[])
-          Spree::Stock::Package.new(stock_location, order, contents)
+          @packer.package_factory.new(stock_location, order, contents)
         end
       end
     end

core/spec/models/spree/stock/splitter/base_spec.rb

@@ -15,6 +15,22 @@ module Splitter
           splitter2.split(packages)
         end
 
+        it 'builds package using package factory' do
+          # Basic extension of Base splitter used to test build_package method
+          class ::BasicSplitter < Base
+            def split(packages)
+              build_package
+            end
+          end
+
+          # Custom package used to test setting package factory
+          class ::CustomPackage
+            def initialize(stock_location, order, splitters); end
+          end
+          allow(Spree::Config).to receive(:package_factory) { CustomPackage }
+
+          expect(::BasicSplitter.new(packer).split(nil).class).to eq CustomPackage
+        end
       end
     end
   end