输入验证失败时如何防止 Multer 文件上传

Question

我正在创建一个 (POST) 路由来处理文件上传，并且除了文件路径之外还将一些其他属性存储到 MongoDB。问题是当输入验证失败时，文件仍然上传到 static(uploads) 文件夹中。

我正在使用 Multer 中间件进行文件上传。

设置

const storage = multer.diskStorage({
  destination: (req, file, cb) => {
    cb(null, "./uploads/");
  },
  filename: (req, file, cb) => {
    cb(null, Date.now() + "-" + file.originalname);
  }
});

const fileFilter = (req, file, cb) => {
  if (file.mimetype === "image/jpeg" || file.mimetype === "image/png") {
    cb(null, true);
  } else {
    //rejects storing a file
    cb(null, false);
  }
};

const upload = multer({
  storage: storage,
  limits: {
    fileSize: 1024 * 1024 * 5
  },
  fileFilter: fileFilter
});

字段

const seamUpload = upload.fields([
  { name: "stylePicture", maxCount: 1 },
  { name: "materialPicture", maxCount: 1 }
]);

路线

router.post("/", [auth, seamUpload], async (req, res) => {
  const { error } = validateSeam(req.body);
  if (error) return res.status(400).send(error.details[0].message);

  const seam = new Seam({
    stylePicture: req.files["stylePicture"][0].path,
    materialPicture: req.files["materialPicture"][0].path,
    description: req.body.description,
    deliveryDate: req.body.deliveryDate,
    customer: req.body.customerId
  });

  await seam.save();

  res.send(seam);
});

Client(PostMan) Screenshot

Answer 1

您可以在 multer 中间件之前安装验证中间件。这样，当验证失败时，所有后续的中间件都不会被执行——因此，文件也不会被上传。

像这样分离验证：

const validateSeamUpload = (req, res, next) => {
    const { error } = validateSeam(req.body);
    if (error) return res.status(400).send(error.details[0].message);
    return next();
};

然后，像这样在 seamUpload 中间件之前安装这个 validateSeamUpload：

router.post("/", [auth, validateSeamUpload, seamUpload], async (req, res) => {
    /** No need for validation here as it was already done in validateSeamUpload */
    const seam = new Seam({
        stylePicture: req.files["stylePicture"][0].path,
        materialPicture: req.files["materialPicture"][0].path,
        description: req.body.description,
        deliveryDate: req.body.deliveryDate,
        customer: req.body.customerId
    });

    await seam.save();

    res.send(seam);
});

顺便说一下，您也可以将它们作为参数传递给 post()。像这样：

router.post("/", /** => See, no need for an array */ auth, validateSeamUpload, seamUpload, async (req, res) => {
    /** your controller code */
});

Answer 2

我遇到过这个问题。我发现的一种解决方案是当您在所有模式下的身份验证都出现错误时，在这种情况下，如果您有来自客户端的文件，您可以像这样轻松删除它：

    if(req.file) {
       fs.unlink(
             path.join(__dirname, "go to root folder that 'req.file.path' leads to the file", req.file.path),
                (err) => console.log(err));
    }

或者如果您有多个文件，您应该对每个文件执行相同的方法。如果有的话，我很高兴在这里。

我希望有另一种方法使用 multer 包来处理它。

祝你好运

输入验证失败时如何防止 Multer 文件上传

How to prevent Multer File Upload when input validation fails

node.js

express

multer

joi