Bring required factory from spree_core

spec/factories/stock_location_factory.rb

@@ -18,5 +18,17 @@ FactoryBot.define do
     state do |stock_location|
       stock_location.country.states.first || stock_location.association(:state, country: stock_location.country)
     end
+
+    factory :stock_location_with_items do
+      after(:create) do |stock_location, evaluator|
+        # variant will add itself to all stock_locations in an after_create
+        # creating a product will automatically create a master variant
+        product_1 = create(:product)
+        product_2 = create(:product)
+
+        stock_location.stock_items.where(:variant_id => product_1.master.id).first.adjust_count_on_hand(10)
+        stock_location.stock_items.where(:variant_id => product_2.master.id).first.adjust_count_on_hand(20)
+      end
+    end
   end
 end

spec/models/spree/stock_item_spec.rb

@@ -3,15 +3,7 @@
 require 'spec_helper'
 
 RSpec.describe Spree::StockItem do
-  let(:stock_location) { create(:stock_location) }
-
-  before do
-    product_1 = create(:product)
-    product_2 = create(:product)
-
-    stock_location.stock_items.where(variant_id: product_1.master.id).first.adjust_count_on_hand(10)
-    stock_location.stock_items.where(variant_id: product_2.master.id).first.adjust_count_on_hand(20)
-  end
+  let(:stock_location) { create(:stock_location_with_items) }
 
   subject { stock_location.stock_items.order(:id).first }