Multer upload is not a function

Question

I'm using Multer to make an upload file system. I followed the instructions of the Github page but it's not working.

const express= require('express');
const app = express();
const multer = require('multer');

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

const upload = multer({ storage: storage });


app.post('/editPhoto',upload.single('avatar'),function(req,res,next){
  upload(req,res,function(err){   
      if(err){
        res.json({success:false,message:err});
        
      }
      else{
        res.json({success:true,message:"Photo was updated !"});
      } 

  });
});

I get TypeError: upload is not a function

What am I doing wrong ?

EDIT

I did as you said and as the doc says.

var storage = multer.diskStorage({
  destination: function (req, file, cb) {
    cb(null, './uploads');
  },
  filename: function (req, file, cb) {
    cb(null, file.fieldname + '-' + Date.now());
  }
});

app.post('/editPhoto',function(req,res,next){

  var upload = multer({ storage:storage}).single('userPhoto');
  upload(req,res,function(err){   
      console.log(req.file);
      if(err){
        res.json({success:false,message:err});
      }
      else{
        res.json({success:true,message:"Photo was updated !"});
      } 
  });
});

req.file is undefined

and when i try like this

var upload = multer({ storage:storage});

app.post('/editPhoto',function(req,res,next){
  upload(req,res,function(err){   
      console.log(req.file);
      if(err){
        res.json({success:false,message:err});
      }
      else{
        res.json({success:true,message:"Photo was updated !"});
      } 
  });
});

I get upload is not a function

Answer 1

As @Aabid told in The comments you will not need to use both, the multer middleware and upload in the controller.

You can use:

app.post('/editPhoto', upload.single('avatar'), (req, res, next) => {
   // here in the req.file you will have the uploaded avatar file
})

Or you can use:

app.post('/editPhoto', (req, res, next) => {
  upload(req, res, function (err) {
    if (err) {
      // This is a good practice when you want to handle your errors differently

      return
    }

    // Everything went fine 
  })
})

So you use one of the 2 methods, not both at the same time.