TypeError: Cannot read properties of undefined (reading 'strEmail') How can I solve this problem?

Question

I'm using Express.js writing this code to make a simple login post request:

app.post("/login", (req, res) => {
  res.send(
    {
    isUserRegistered: userLogin(req.body.strEmail, req.body.strPassword),
    }
  )
})

function userLogin(strEmail, strPassword) {
  if (strEmail.includes("mike@gmail.com") , strPassword.includes("12345")) {
    return true;
  } else {
    return false;
  }
}

My Body (raw):

{
    "strEmail":"mike@gmail.com",
    "strPassword":"12345"
}

And the expected response is isUserRegistered:True which depends on what i will pass in the body in postman, Any help?

Answer 1

The problem is with the scope here.

create a folder called utils and create a userAuthentication.js file there. userAuthentication.js:

function userLogin(strEmail, strPassword) {
  if (strEmail === "mike@gmail.com" && strPassword === "12345") {
    return true;
  } else {
    return false;
  }
}

module.exports = userLogin;

In your app.js or index.js file:

const express = require('express');
const userLogin = require('../utils/userAuthentication');
const app = express();
const port = 4000;

app.use(express.json());

app.post('/login', (req, res) =>{
  const { strEmail, strPassword } = req.body;
  const isAuthenticated = userLogin(strEmail, strPassword);
  if (isAuthenticated) {
    res.status(200).json({
      status: 'Ok',
      message: 'A user successfully logged in'
    });
  } else {
    res.status(500).json({
      status: 'Fail',
      message: 'Wrong credentials'
    }
});