Check if a string is a valid email address

isValidEmail.js

/**
 * Check if a string is a valid email address
 * {@link https://gist.github.com/kieranbarker/55a12cac034c386a5b3669b991290bf6}
 * @param {String} str The string
 * @returns {Boolean} Whether the string is a valid email address
 */
function isValidEmail (str) {
  // The regular expression used by [type="email"]
  // https://html.spec.whatwg.org/multipage/input.html#valid-e-mail-address
  const regex = /^[a-zA-Z0-9.!#$%&'*+\/=?^_`{|}~-]+@[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?(?:\.[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?)*$/;

  // Test the string against the regular expression
  return regex.test(str);
}