Fix(Admin menus): Stable promotion menu items

This makes sure that the promotion menus are always below the product
menu item, in both new admin and the backend.

It also changes the nomenclature to be "Promotions" for the legacy
promotion system and "Promotions (new)" for the new promotion system.

legacy_promotions/config/locales/en.yml

@@ -1,4 +1,8 @@
 en:
+  solidus_admin:
+    menu_item:
+      legacy_promotions: Promotions
+      legacy_promotion_categories: Promotion Categories
   spree:
     admin:
       promotion_status:
@@ -23,8 +27,8 @@ en:
           general: General
           starts_at_placeholder: Immediately
       tab:
-        promotions: Legacy Promotions
-        promotion_categories: Legacy Promotion Categories
+        legacy_promotions: Promotions
+        legacy_promotion_categories: Promotion Categories
     back_to_promotion_categories_list: Back To Promotions Categories List
     back_to_promotions_list: Back To Promotions List
     base_amount: Base Amount

legacy_promotions/lib/solidus_legacy_promotions/engine.rb

@@ -42,10 +42,22 @@ class Engine < ::Rails::Engine
       if SolidusSupport.admin_available?
         SolidusAdmin::Config.configure do |config|
           config.menu_items << {
-            key: "promotions",
+            key: "legacy_promotions",
             route: -> { spree.admin_promotions_path },
             icon: "megaphone-line",
-            position: 30
+            position: 1.5,
+            children: [
+              {
+                key: "legacy_promotions",
+                route: -> { spree.admin_promotions_path },
+                position: 1
+              },
+              {
+                key: "legacy_promotion_categories",
+                route: -> { spree.admin_promotion_categories_path },
+                position: 2
+              }
+            ]
           }
         end
       end

promotions/config/locales/en.yml

@@ -2,11 +2,15 @@
 # See https://github.com/svenfuchs/rails-i18n/tree/master/rails%2Flocale for starting points.
 
 en:
+  solidus_admin:
+    menu_item:
+      promotions: Promotions (new)
+      promotion_categories: Promotion Categories (new)
   spree:
     admin:
       tab:
-        solidus_promotions: Promotions
-        solidus_promotion_categories: Promotion Categories
+        promotions: Promotions (new)
+        promotion_categories: Promotion Categories (new)
     hints:
       solidus_promotions/promotion:
         expires_at: This determines when the promotion expires. <br> If no value is specified, the promotion will never expire.

promotions/lib/solidus_promotions/engine.rb

@@ -60,6 +60,31 @@ class Engine < Rails::Engine
       end
     end
 
+    initializer "solidus_promotions.add_solidus_admin_menu_items", after: "spree.load_config_initializers" do
+      if SolidusSupport.admin_available?
+        SolidusAdmin::Config.configure do |config|
+          config.menu_items << {
+            key: "promotions",
+            route: -> { solidus_promotions.admin_promotions_path },
+            icon: "megaphone-line",
+            position: 1.6,
+            children: [
+              {
+                key: "promotions",
+                route: -> { solidus_promotions.admin_promotions_path },
+                position: 1
+              },
+              {
+                key: "promotion_categories",
+                route: -> { solidus_promotions.admin_promotion_categories_path },
+                position: 1
+              }
+            ]
+          }
+        end
+      end
+    end
+
     initializer "solidus_promotions.add_backend_menus", after: "spree.backend.environment" do
       if SolidusSupport.backend_available?
         promotions_menu_item = Spree::BackendConfiguration::MenuItem.new(
@@ -82,8 +107,12 @@ class Engine < Rails::Engine
           ]
         )
 
+        # We want to appear after the legacy promotions menu item if it exists, otherwise after the products menu item
         product_menu_item_index = Spree::Backend::Config.menu_items.find_index { |item| item.label == :products }
-        Spree::Backend::Config.menu_items.insert(product_menu_item_index + 1, promotions_menu_item)
+        legacy_promotions_menu_item = Spree::Backend::Config.menu_items.find_index { |item| item.label == :legacy_promotions }
+        promotions_menu_index = [product_menu_item_index, legacy_promotions_menu_item].compact.max + 1
+
+        Spree::Backend::Config.menu_items.insert(promotions_menu_index, promotions_menu_item)
       end
     end
   end