呗踩我...

let handleBundleComplete = async () => {
      //不知道什么意思...
      handleBundleComplete = stats => !stats.stats[1].compilation.errors.length && runServer();

      const server = await runServer();
      const bs = browserSync.create();

      bs.init({
        ...isDebug ? {} : { notify: false, ui: false },

        proxy: {
          target: server.host,
          middleware: [wpMiddleware, hotMiddleware],
          proxyOptions: {
            xfwd: true,
          },
        },
      }, resolve);
    };

不明白这样的写法的含义？在函数内给函数自身赋值？

let handleBundleComplete = async () => {
    handleBundleComplete = (...) => {...}
    ...
}