instance method locals_code

# File actionview/lib/action_view/template.rb, line 325
      def locals_code
        # Only locals with valid variable names get set directly. Others will
        # still be available in local_assigns.
        locals = @locals - Module::RUBY_RESERVED_KEYWORDS
        deprecated_locals = locals.grep(/\A@+/)
        if deprecated_locals.any?
          ActiveSupport::Deprecation.warn(<<~MSG)
            Passing instance variables to `render` is deprecated.
            In Rails 7.1, #{deprecated_locals.to_sentence} will be ignored.
          MSG
          locals = locals.grep(/\A@?(?![A-Z0-9])(?:[[:alnum:]_]|[^\0-\177])+\z/)
        else
          locals = locals.grep(/\A(?![A-Z0-9])(?:[[:alnum:]_]|[^\0-\177])+\z/)
        end

        # Assign for the same variable is to suppress unused variable warning
        locals.each_with_object(+"") { |key, code| code << "#{key} = local_assigns[:#{key}]; #{key} = #{key};" }
      end