submit-social-housing-lettings-and-sales-data/app/postcode_app.rb

module FormatPostcode
    refine FormatPostcode do
    def formatted_postcode
      postcode = upcase.gsub(/\s+/, "")
      case postcode.length
      when 5
        postcode.insert(2, " ")
      when 6
        postcode.insert(3, " ")
      when 7
        postcode.insert(4, " ")
      else
        self
      end
    end
  end