passport-next/passport-local

'use strict';
exports.lookup = (obj, field) => {
  if (!obj) { return null; }
  const chain = field.split(']').join('').split('[');
  for (let i = 0, len = chain.length; i < len; i++) {
    const prop = obj[chain[i]];
    if (typeof (prop) === 'undefined') { return null; }
    if (typeof (prop) !== 'object') { return prop; }
    obj = prop;
  }
  return null;
};