Hello I am new to reacts. I am implementing reactJs Login system. I want to verify my user from backend(MongoDb) then to show User Dashboard. I tried some similar problems but didn't get my solution

What is Problem

Whenever i am trying to login, by giving username and password, it redirects to user dashboard. By giving wrong email or password also it goes to user dashboard

what i Tried

I tried all the logic behind but the problem is same

Login.jsx(react)

import React, { useState } from 'react'
import { NavLink } from 'react-router-dom'
import zerotwo from "../images/02.svg"
import { useNavigate } from 'react-router-dom';


const Login = () => {
    const navigate = useNavigate()

    const [detail, setDetail] = useState({  
        email: "",  
        password: "",
    })

    let name, value
    const handleInput = (e) => {
        name = e.target.name
        value = e.target.value
        setDetail({ ...detail, [name]: value })
    }

    const PostData = async (e) => {
        
        e.preventDefault()
        const {  email, password } = detail
        
        const res = await fetch("/login", {
            
            method: "POST",
            headers: {
                'Content-Type': 'application/json',
                'Accept': 'application/json'
            },

            body: JSON.stringify({
                 email, password
            })
        })

        const data = await res.json()
        

        if (data === 400 || !data) {
            alert("not registered")
            navigate('/')
        } else {
            alert("Sucesssfuly")
            navigate('/dashboard')
        }
    }

app.js(backend)

router.post("/login", async (req, res) => {
    let token
    try {
        const { email, password } = req.body
        if (!email || !password) {
            return res.status(400).json({ message: "fill the credentials" })
        }

        const UserLogin = await User.findOne({ email: email })

        if (UserLogin) {

            const passmatch = await bcrypt.compare(password, UserLogin.password)

            token = await UserLogin.generateAuthToken()
            // console.log(token);
            res.cookie("jwt",token,{
                expires : new Date(Date.now() 25892000000),
                httpOnly : true
            })

            if (!passmatch) {
                res.status(400).json({ error: "Invalid credentials" })
            }
            else {
                res.status(200).json({ message: "sign in successfully" })
            }
        } else {
            res.status(400).json({ error: "Invalid credentials" })
        }

    } catch (err) {
        console.log(err);
    }
})

I tried all logics behind in verifying username and password. I am expecting to verify user properly by his/her username and password

CodePudding user response：

You are checking data object on status code here - data === 400, but it will never be true, cause you returning object { error: "Invalid credentials" } if creds are invalid. You probably wanted to check the response status code, so it should be

if (res.status === 400)

Also, side note - I would recommend to return 401 status code for Authentication error (wrong password), it specifically designed for such cases and it is standard. 400 in this case could be if for example empty username or password were provided - that would make sense, cause 400 error is more for validation.