Error: Route.post() requires a callback function but got a [object Object]

Description

const express = require('express');
const router = express.Router();
const Note = require('../models/Note');
const { body, validationResult } = require('express-validator');
const fetchuser = require('../middleware/fetchuser');


// ROUTE 2: Add a new Note using: POST "/api/notes/addnote". Login required
router.post('/', fetchuser, [
    body('title', 'Enter a valid title').isLength({ min: 3 }),
    body('description', 'Description must be atleast 5 characters').isLength({ min: 5 }),], async (req, res) => {
        try {
            const { title, description, tag } = req.body;

            // If there are errors, return Bad request and the errors
            const errors = validationResult(req);
            if (!errors.isEmpty()) {
                return res.status(400).json({ errors: errors.array() });
            }
            const note = new Note({
                title, description, tag, user: req.user.id
            })
            const savedNote = await note.save()

            res.json(savedNote)

        } catch (error) {
            console.error(error.message);
            res.status(500).send("Internal Server Error");
        }
    })



module.exports = router

Contributor guide

Tech stack

nodejsexpress

Domain

backend

Issue type

bug

DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.

3

Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.

under 1 hour

Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.

fresh

ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.

mostly clear

Prerequisites

Express middleware basicsfunction vs object

Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.

70

Research direction

Investigate the fetchuser middleware: verify that it exports a function, not an object. The error 'Route.post() requires a callback function but got a [object Object]' suggests that fetchuser is an object. Look at the file '../middleware/fetchuser' (likely fetchuser.js) to confirm its export. If it's an object, change it to export a function that returns the middleware. Additionally, ensure no other arguments are mistakenly passed as objects.