Adds types

app/models/collection.rb

@@ -1,4 +1,7 @@
+# typed: true
+
 class Collection < ApplicationRecord
+  extend T::Sig
   # Associations
   belongs_to :user
   belongs_to :parent_collection, class_name: "Collection", optional: true
@@ -15,30 +18,36 @@ class Collection < ApplicationRecord
   scope :root_collections, -> { where(parent_collection_id: nil) }
 
   # Instance methods
+  sig { returns(Integer) }
   def game_count
     games.count
   end
 
+  sig { returns(Integer) }
   def total_game_count
     game_count + subcollections.sum(&:total_game_count)
   end
 
+  sig { returns(T::Boolean) }
   def root?
     parent_collection_id.nil?
   end
 
+  sig { returns(T::Boolean) }
   def subcollection?
     parent_collection_id.present?
   end
 
   private
 
+  sig { void }
   def cannot_be_own_parent
     if parent_collection_id.present? && parent_collection_id == id
       errors.add(:parent_collection_id, "cannot be itself")
     end
   end
 
+  sig { void }
   def subcollection_depth_limit
     if parent_collection.present? && parent_collection.parent_collection.present?
       errors.add(:parent_collection_id, "cannot nest more than one level deep")