index.js

import React from "react";
import { string } from "prop-types";
import { Helmet } from "react-helmet";

export default function Head({ title, description, ...props }) {
  return (
    <Helmet {...props}>
      <title>{title}</title>
      <meta name="description" content={description} />
    </Helmet>
  );
}

Head.defaultProps = {
  title: "",
  description: ""
};

Head.propTypes = {
  title: string,
  description: string,
  ...Helmet.propTypes
};