[Aetae]

function asyncGeocode(params) {
  return new Promise((resolve, reject) => geocoder.geocode(
    params, 
    (results, status) => status === 'OK' ? resolve(results) : reject(status)
  ));
}

async function addressToCoords(local) {
  var address = local;
  var result = await asyncGeocode({address}).catch(status => {
    console.log('Error: ' + status);
    return '';
  });

  alert('Result is ' + result);
  return result;
}

Подробнее...