text: 'use strict'
  
  const isNumeric = require('isnumeric')
  
  const validPostalCode = /^\d{5}$/
  
  const assertValidPostalCode = (code) => {
  	if(!isNumeric(code) || !validPostalCode.test(code)) {
  		throw new Error(`Invalid postal code: ${code}`)
  	}
  }
  
  module.exports = {assertValidPostalCode}
  