req.file.stream 未定义

Posted 2023-02-19

【中文标题】req.file.stream 未定义

【英文标题】：req.file.stream is undefined

【发布时间】：2021-08-19 07:28:46

【问题描述】：

我在使用节点 16 和 ES6 时遇到问题。我正在尝试制作一个上传文件控制器，但我遇到了未定义的 req.file.stream 我正在使用 multer 来处理上传文件。

第一个问题是 __dirname undefined，我可以使用路径和新 URL 来修复它。

我在管道中遇到的错误

node:internal/process/promises:246
          triggerUncaughtException(err, true /* fromPromise */);
          ^

TypeError [ERR_INVALID_ARG_TYPE]: The "source" argument must be of type function or an instance of Stream, Iterable, or AsyncIterable. Received undefined

我的 userRoutes.js

import express from "express";
import  signin, signup, logout  from "../Controller/AuthController.js";
import 
  getUsers,
  getUser,
  updateUser,
  deleteUser,
  follow,
  unfollow,
 from "../Controller/UserController.js";
import  upload  from "../Controller/UploadController.js";
import multer from "multer";

const router = express.Router();
// Auth
router.post("/signin", signin);
router.post("/signup", signup);
router.post("/logout", logout);

// users
router.get("/", getUsers);
router.get("/:id", getUser);
router.patch("/:id", updateUser);
router.delete("/:id", deleteUser);
router.patch("/follow/:id", follow);
router.patch("/unfollow/:id", unfollow);

// upload
router.post("/upload", multer().single("file"), upload);
export default router;

还有我的 UploadController.js

import fs from "fs";
import  promisify  from "util";
import stream from "stream";

const pipeline = promisify(stream.pipeline);
// const  uploadErrors  = require("../utils/errors.utils");
import path from "path";
const __dirname = path.dirname(new URL(import.meta.url).pathname);

export const upload = async (req, res) => 
  try 
    // console.log(req.file);
    console.log(__dirname);
    if (
      !req.file.mimetype == "image/jpg" ||
      !req.file.mimetype == "image/png" ||
      !req.file.mimetype == "image/jpeg"
    )
      throw Error("invalid file");

    if (req.file.size > 2818128) throw Error("max size");
   catch (err) 
    const errors = uploadErrors(err);
    return res.status(201).json( err );
  
  const fileName = req.body.name + ".jpg";
  await pipeline(
    req.file.stream,
    fs.createWriteStream(
      `$__dirname/../client/public/uploads/profil/$fileName`
    )
  );

  try 
    await User.findByIdAndUpdate(
      req.body.userId,
       $set:  picture: "./uploads/profil/" + fileName  ,
       new: true, upsert: true, setDefaultsOnInsert: true ,
      (err, docs) => 
        if (!err) return res.send(docs);
        else return res.status(500).send( message: err );
      
    );
   catch (err) 
    return res.status(500).send( message: err );
  
;

【参考方案1】：

Multer 将文件作为缓冲区而不是流提供给您。 req.file.stream 不是有效属性，但 req.file.buffer 是：https://github.com/expressjs/multer#file-information。

从您的代码的外观来看，您正在尝试将文件保存在磁盘上。为此，您可以使用 multer 的 DiskStorage。创建一个存储实例并将其作为配置传递给 multer 实例：

const storage = multer.diskStorage(
  destination: function (req, file, cb) 
    cb(null, `$__dirname/../client/public/uploads/profil/`);
  ,
  filename: function (req, file, cb) 
    cb(null, req.body.name + '.jpg');
  ,
);

const upload = multer( storage );

router.post('/upload', upload.single('file'), upload);

看看这个免费的Request Parsing in Node.js Guide 在 Node.js 中处理文件上传。

【参考方案2】：

如果你想使用req.file.stream，你需要安装这个版本的multer：

npm install --save multer@^2.0.0-rc.1

您的代码将完美运行，只需将您的 req.file.mimetype 更改为 req.file.detectedMimeType !!