relative-path-to.js

import PropTypes from "prop-types";
/**
 * Find relative path from to to pathname
 * @param {String} to
 * @param {String} pathname
 * @returns {String} rlative path
 */
export const relative = (to, pathname) => {
  let to_list = to.split("/");
  let to_obj = Object.fromEntries(to.split("/").entries());
  let pathname_list = Object.fromEntries(pathname.split("/").entries());

  let key;
  for (key = 0; key <= to_list.length; key++) {
    const match = to_obj[key] == pathname_list[key];
    if (!match) {
      break;
    }
  }
  return to_list.slice(key, to_list.length).join("/");
};
relative.propTypes = {
  to: PropTypes.string.isRequired,
  pathname: PropTypes.string.isRequired,
};

export default { relative };