Prevent migration code lens from failing in unsaved files

Author: vinistock

lib/ruby_lsp/ruby_lsp_rails/code_lens.rb

@@ -152,8 +152,9 @@ def on_class_node_enter(node)
         end
 
         if superclass_name&.start_with?("ActiveRecord::Migration")
-          command = "#{migrate_command} VERSION=#{migration_version}"
-          add_migrate_code_lens(node, name: class_name, command: command)
+          version = migration_version
+          command = "#{migrate_command} VERSION=#{version}"
+          add_migrate_code_lens(node, name: class_name, command: command) if version
         end
       end
 
@@ -241,7 +242,9 @@ def migrate_command
 
       sig { returns(T.nilable(String)) }
       def migration_version
-        File.basename(T.must(@path)).split("_").first
+        return unless @path
+
+        File.basename(@path).split("_").first
       end
 
       sig { params(node: Prism::Node, name: String, command: String).void }