Import Express Routes causes Request Body to be Undefined

Question

I am using express to build a mongodb + auth0 app.

My requests maintain their body when they are placed in index.js, but as soon as I move into another js file in the project, it returns undefined, where headers and other req attributes are maintained.

index.js

const express = require('express')
const app = express();
const port = 8000;

var loginRoutes = require('./routes/login');

app.use(express.json());

const clientPromise = require('./mongodb-client');

app.use('/login', loginRoutes);

/routes/login.js

const express = require('express')
router = express.Router();

const clientPromise = require('../mongodb-client');

const auth0 = require('../auth0-client');

const app = express();
app.use(express.json());

const {ObjectId} = require("mongodb");

//LOGIN USER
router.post('/', async function(req, res) {
    console.log(JSON.stringify(req.body));

    var data = {
        username: req.body.username,
        password: req.body.password
      };

     auth0.passwordGrant(data, function (err, userData) {
        if (err) {
          // Handle error.
        }
      
        console.log(userData);
      });

    res.send({'login': 'yes'})
})

module.exports = router;

I'm assuming it has something to do with express.json() and maybe some OOO issue? But I'm drawing on the search engines and can't figure out what to troubleshoot next.

Answer 1

app.use(express.json()); must come before var loginRoutes = require('./routes/login'); for the request body to parse and be successfully passed to the child login route.