Set StockLocation.backorderable_default to false in DefaultStockLocation and in StockLocation factory.

This makes the default value of variant.on_demand false in all environments and in tests.

Additionally, adapt VariantStock.on_demand test and product factory to this change (setting on_hand value in product factory so it's not out of stock by default).

app/services/default_stock_location.rb

@@ -6,7 +6,7 @@ class DefaultStockLocation
   def self.create!
     country = Spree::Country.find_by_iso(ENV['DEFAULT_COUNTRY_CODE'])
     state = country.states.first
-    Spree::StockLocation.create!(name: NAME, country_id: country.id, state_id: state.id)
+    Spree::StockLocation.create!(name: NAME, country_id: country.id, state_id: state.id, backorderable_default: false)
   end
 
   def self.destroy_all

spec/factories.rb

@@ -551,19 +551,26 @@ FactoryBot.define do
       on_hand { 5 }
     end
     after(:create) do |product, evaluator|
-      product.variants.first.tap do |variant|
-        variant.on_demand = evaluator.on_demand
-        variant.count_on_hand = evaluator.on_hand
-        variant.save
-      end
+      product.master.on_demand = evaluator.on_demand
+      product.master.on_hand = evaluator.on_hand
+      product.variants.first.on_demand = evaluator.on_demand
+      product.variants.first.on_hand = evaluator.on_hand
     end
   end
 end
 
-
 FactoryBot.modify do
   factory :product do
+    transient do
+      on_hand { 5 }
+    end
+
     primary_taxon { Spree::Taxon.first || FactoryBot.create(:taxon) }
+
+    after(:create) do |product, evaluator|
+      product.master.on_hand = evaluator.on_hand
+      product.variants.first.on_hand = evaluator.on_hand
+    end
   end
 
   factory :base_product do
@@ -661,6 +668,9 @@ FactoryBot.modify do
 
     # Ensures the name attribute is not assigned after instantiating the default location
     transient { name 'default' }
+
+    # sets the default value for variant.on_demand
+    backorderable_default false
   end
 
   factory :shipment, class: Spree::Shipment do

spec/models/concerns/variant_stock_spec.rb

@@ -135,7 +135,7 @@ describe VariantStock do
       let(:variant) { build(:variant) }
 
       it 'returns stock location default' do
-        expect(variant.on_demand).to be_truthy
+        expect(variant.on_demand).to be_falsy
       end
     end
   end