Javascript 我无法从服务器下载 zip 存档

我有一个Reaction客户端和一个Node服务器.当我向服务器发送POST请求时，服务器应该压缩文件夹并将其下载到客户端.这是做不到的.将损坏的存档下载到客户端. 此外，服务器上的存档创建正确.

下面的代码示例 Reaction客户端

function test() {
    fetch("http://localhost:5000/download", {
      method: 'POST'
    })
    .then(res => res.blob())
    .then(data => {
      let url = URL.createObjectURL(data)
      let anchor = document.createElement('a')
      anchor.href = url
      anchor.download = 'ex_new.zip'
      document.body.appendChild(anchor)
      anchor.style = 'display: none'
      anchor.click()
      anchor.remove()

      URL.revokeObjectURL(url)
      document.removeChild(anchor)
    })
}

function App() {
  return (
    <button onClick={() => test()}>Test</button>
  );
}

export default App;

node 服务器

const archiver = require("archiver")
const express = require("express")
const cors = require("cors")
const fs = require("fs")
const path = require('path')


const app = express()
app.use(cors())

app.post("/download", (req, res) => {

    const archive = archiver('zip')
    archive.directory('output')
    archive.finalize()
    const output = fs.createWriteStream(__dirname + '/ex.zip')
    archive.pipe(output)
    return res.download('/home/user/Js', 'ex.zip')
})

app.listen(5000, () => console.log("Server start"))

Screenshot old error个

Screenshot new error个

Screenshot Chrome error个

Networks Chrome个