export default function makeCancelable(thenable) {
  let isCanceled = false;
  const promise = Promise.resolve(thenable).then(
    function(result) {
      if (isCanceled) throw Object.freeze({ isCanceled });
      return result;
    },
    function(error) {
      if (isCanceled) throw Object.freeze({ isCanceled, error });
      throw error;
    }
  );
  return Object.assign(Object.create(promise), {
    then: promise.then.bind(promise),
    cancel() {
      isCanceled = true;
    },
  });
}