/** 串行化上传，避免微信 JSSDK 并发选图/读图导致卡死 */
let uploadChain: Promise<unknown> = Promise.resolve();

export function enqueueUpload<T>(task: () => Promise<T>): Promise<T> {
  const next = uploadChain.then(task, task);
  uploadChain = next.then(
    () => undefined,
    () => undefined,
  );
  return next;
}