Abstract OFN's default stock location into a class

app/services/default_stock_location.rb

@@ -0,0 +1,15 @@
+# Encapsulates the concept of default stock location that OFN has, as explained
+# in https://github.com/openfoodfoundation/openfoodnetwork/wiki/Spree-Upgrade%3A-Stock-locations
+class DefaultStockLocation
+  NAME = 'OFN default'.freeze
+
+  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)
+  end
+
+  def self.destroy_all
+    Spree::StockLocation.where(name: NAME).destroy_all
+  end
+end

spec/factories.rb

@@ -656,8 +656,10 @@ end
 
 FactoryBot.modify do
   factory :stock_location, class: Spree::StockLocation do
+    name { 'default' }
+
     # keeps the test stock_location unique
-    initialize_with { Spree::StockLocation.find_or_create_by_name(name)}
+    initialize_with { DefaultStockLocation.find_or_create }
   end
 
   factory :shipment, class: Spree::Shipment do

spec/services/default_stock_location_spec.rb

@@ -0,0 +1,32 @@
+require 'spec_helper'
+
+describe DefaultStockLocation do
+  describe '.create!' do
+    it "names the location 'OFN default'" do
+      stock_location = described_class.create!
+      expect(stock_location.name).to eq('OFN default')
+    end
+
+    it 'sets the location in the default country' do
+      default_country = Spree::Country.find_by_iso(ENV['DEFAULT_COUNTRY_CODE'])
+      stock_location = described_class.create!
+      expect(stock_location.country).to eq(default_country)
+    end
+
+    it 'sets the first state in the country' do
+      default_country = Spree::Country.find_by_iso(ENV['DEFAULT_COUNTRY_CODE'])
+      stock_location = described_class.create!
+      expect(stock_location.state).to eq(default_country.states.first)
+    end
+  end
+
+  describe '.destroy_all' do
+    it "removes all stock locations named 'OFN default'" do
+      create(:stock_location, name: 'OFN default')
+      create(:stock_location, name: 'OFN default')
+
+      expect { described_class.destroy_all }
+        .to change { Spree::StockLocation.count }.from(2).to(0)
+    end
+  end
+end