You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: evaluating_parser_spec.rb
    path of file: ./repos/puppet/spec/unit/pops/evaluator
    
    the code of the file until where you have to start completion: require 'spec_helper'

require 
    
        def assert_no_undef(x)
          case x
          when Array
            return unless x.include?(:undef)
          when Hash
            return unless x.keys.include?(:undef) || x.values.include?(:undef)
          else
            return unless x == :undef
          end