javascript - Weird behavior using parent/child routing file

Question

I have a Node/Express backend with TypeScript.

If I run the root route in Postman localhost:8000/ after changing and saving a file I get a proper response. However, if I run localhost:8000/user after changing and saving a file I get an automatic 404 HTML response.

Only if I first run the root route and only then run the child route, does it work.

What am I doing wrong here?

index.ts

// External
import express from 'express';
import mongoose from 'mongoose';
import bodyParser from 'body-parser';

// Internal
import { uri } from '../backend/config/dbConsts';
import masterRoute from './api/masterRoute';

module.exports.mongoose = mongoose;

const app = express();
const PORT = 8000;

app.use(bodyParser.urlencoded({ extended: true }));

// Defines the routes used.
app.use('/', masterRoute);

app.listen(PORT, () => {
  console.log(`??[server]: Server is running at https://localhost:${PORT}`);

  mongoose.connect(uri, { useNewUrlParser: true, useUnifiedTopology: true });
  var db = mongoose.connection;
  db.on('error', console.error.bind(console, 'MongoDB connection error:'));
});

export default app;

masterRoute.ts

import express, { Router } from 'express';
import userRoute from './routes/user.route';
const router: Router = express.Router();

router.get('/', async (req, res, next) => {
  router.use('/user', userRoute);
  
  // Returning 400 here since all requests must enter into an actual routing file.
  res.status(400).send('Bad route. masterRouter.');
});

export default router;

userRoute.ts

import express, { Router } from 'express';
const router: Router = express.Router();
import userController from '../../controllers/user.controller';

router.get('/', async (req, res, next) => {
  try {
    const users = await userController.getAllUsers();
    res.status(200).send(users);
  } catch (err) {
    next(err);
  }

});

});

export default router;

question from:https://stackoverflow.com/questions/65951363/weird-behavior-using-parent-child-routing-file

Answer 1

I figured out my issue. I had designed the routing system incorrectly.

I deleted the master routing file entirely. Here is the updated index.ts file.

// External
import express from 'express';
import mongoose from 'mongoose';
import bodyParser from 'body-parser';

// Internal
import { uri } from '../backend/config/dbConsts';
import masterRoute from './api/masterRoute';

module.exports.mongoose = mongoose;

const app = express();
const PORT = 8000;

app.use(bodyParser.urlencoded({ extended: true }));

// Defines the routes used.
app.use('/', userRoute);
app.use('/second', secondRoute);

app.listen(PORT, () => {
  console.log(`??[server]: Server is running at https://localhost:${PORT}`);

  mongoose.connect(uri, { useNewUrlParser: true, useUnifiedTopology: true });
  var db = mongoose.connection;
  db.on('error', console.error.bind(console, 'MongoDB connection error:'));
});

export default app;