index.js

import express from "express"
// const express = require ("express")
import cors from "cors"
import mongoose from "mongoose"

const app = express()
app.use(express.json())
app.use(express.urlencoded())
app.use(cors())

mongoose.connect("mongodb://localhost:27017/userDB",{
    useNewUrlParser: true,
    useUnifiedTopology: true
}, () => {
    console.log("DB connected")
})

const userSchema = mongoose.Schema({
    name: String,
    email: String,
    password: String
})

const User = new mongoose.model("User", userSchema)
//Routes
app.post("/login",(req,res)=>{

    const {email, password} = req.body
    User.findOne({email: email},(err,user) =>{
        if(user){
            if (password === user.password){
                res.send({message: "Login Successfull",user: user})
            }else{
                res.send({message: "password doesnot match"})
            }
        }else{
            res.send({message: "User not registered"})
        }
    })

})

app.post("/signup",(req,res)=>{
    const {name, email, password} = req.body
   User.findOne({email: email}, (err, user) => {
        if(user){
            res.send({message: "User already exists"})
        }else{

            const user = new User({
                name,
                email,
                password,
            })
            user.save( err => {
                if(err){
                    res.send(err)
                }else{
                    res.send({message: "Succesfully registered"})
                }
            })
        }
   })
})

app.listen(9002,() =>{
    console.log("BE started at port 9002")
})