Remove some N+1s relating to address (found with bullet gem)

app/controllers/producers_controller.rb

@@ -8,7 +8,7 @@ class ProducersController < BaseController
       .activated
       .visible
       .is_primary_producer
-      .includes(address: :state)
+      .includes(address: [:state, :country])
       .includes(:properties)
       .includes(supplied_products: :properties)
       .all

app/controllers/shops_controller.rb

@@ -8,7 +8,7 @@ class ShopsController < BaseController
       .activated
       .visible
       .is_distributor
-      .includes(address: :state)
+      .includes(address: [:state, :country])
       .includes(:properties)
       .includes(supplied_products: :properties)
       .all

app/helpers/injection_helper.rb

@@ -3,7 +3,7 @@ require 'open_food_network/enterprise_injection_data'
 module InjectionHelper
   include SerializerHelper
 
-  def inject_enterprises(enterprises = Enterprise.activated.includes(address: :state).all)
+  def inject_enterprises(enterprises = Enterprise.activated.includes(address: [:state, :country]).all)
     inject_json_ams(
       "enterprises",
       enterprises,
@@ -35,13 +35,15 @@ module InjectionHelper
 
     inject_json_ams(
       "enterprises",
-      Enterprise.activated.visible.select(select_only).includes(address: :state).all,
+      Enterprise.activated.visible.select(select_only).includes(address: [:state, :country]).all,
       Api::EnterpriseShopfrontListSerializer
     )
   end
 
   def inject_enterprise_and_relatives
-    inject_json_ams "enterprises", current_distributor.relatives_including_self.activated.includes(address: :state).all, Api::EnterpriseSerializer, enterprise_injection_data
+    inject_json_ams "enterprises",
+                    current_distributor.relatives_including_self.activated.includes(address: [:state, :country]).all,
+                    Api::EnterpriseSerializer, enterprise_injection_data
   end
 
   def inject_group_enterprises

app/helpers/spree/base_helper_decorator.rb

@@ -5,5 +5,21 @@ module Spree
     def variant_options(v, _options = {})
       v.options_text
     end
+
+    # Overriden to eager-load :states
+    def available_countries
+      checkout_zone = Zone.find_by_name(Spree::Config[:checkout_zone])
+
+      if checkout_zone && checkout_zone.kind == 'country'
+        countries = checkout_zone.country_list
+      else
+        countries = Country.includes(:states).all
+      end
+
+      countries.collect do |country|
+        country.name = Spree.t(country.iso, scope: 'country_names', default: country.name)
+        country
+      end.sort { |a, b| a.name <=> b.name }
+    end
   end
 end