In multer file extension which shouldnt be saved getting saved-CodePudding

TASK OF CODE : The code telling multer to save file with pdf extension

PROBLEM : I am getting back error in response but the file getting saved inside the folder

const express = require("express");
const app = new express();
const multer = require("multer");
const upload = multer({
  dest: "images", // destination to save the image
  limits: 100000, // limiting the size of file to 1mb and 1 mb = 100000bytes
  fileFilter(req, file, cb) {
    if (!file.originalname.endsWith("pdf")) {
      cb(new Error("please upload PDF file extension")); // sending error
    }
    cb(undefined, true);
    // 3 type of call backs
    // cb(new Error('please upload PDF file extension'));// sending error
    // cb(undefined,true)// undefined means no error and true means accepting file
    // cb(undefined,false)// undefined means no error and true means rejecting file
  },
});
app.post("/upload", upload.single("upload"), (req, res) => {
  res.send();
});
app.listen(8000, () => {
  console.log("server fired off");
});

The error message is correct as per what I want enter image description here But the file is getting saved in images folder which should not be saved because I am sending jpg extension

CodePudding user response：

Looks like the problem is that the code execution continues after cb(new Error(..), thus cb(undefined,true) gets called as well, telling multer that everything is ok. Change it to:

if (!file.originalname.toLowerCase().endsWith("pdf")) {
  return cb(new Error("please upload PDF file extension")); // sending error
}
cb(undefined, true);

Note that I also used .toLowerCase() just to be sure that files with a.PDF extension get uploaded.

CodePudding user response：

I'm making this new function called checkFileType()

function checkFileType(file, cb){
   const filetypes = /pdf/;
   const extname = filetypes.test(file.originalname.split('.')[file.originalname.split('.').length-1]);
   const mimetype = filetypes.test(file.mimetype);
   if(mimetype && extname){
       return cb(null,true);
   }else{
       cb(error = 'message : please upload PDF file extension');
   }
}

And I implemented it like this

const upload = multer({
   dest: "images", // destination to save the image
   limits: 100000, // limiting the size of file to 1mb and 1 mb = 100000bytes
   fileFilter(req, file, cb) {
    checkFileType(file, cb);
   },
});