如果真的要用 async function ，可以这样用：

let resolve;
const promise = new Promise(r => {
resolve = r;
});

const middleOne = async (req, res, next) => {
next();
const vv = await promise;
console.log(vv, "middle1");
};

const haha = () => {
return new Promise((resolve, _reject) => {
setTimeout(() => {
resolve("hahahahah");
});
});
};

const middleTwo = async (req, res, next) => {
try {
const result = await haha();
resolve({
name: result,
});
next();
} catch (ex) {
next(ex);
}
};