REST API Design — Poora RESTful Biryani API

Let's build a complete RESTful Biryani API using Express Router — the same pattern Swiggy's backend uses for organizing code.

routes/biryani.routes.js — Full CRUD:

import { Router } from 'express';

const router = Router();

// In-memory data store
let menu = [
  { id: 1, name: 'Chicken Biryani', price: 250, spice: 'Medium' },
  { id: 2, name: 'Mutton Biryani', price: 350, spice: 'High' },
  { id: 3, name: 'Veg Biryani', price: 200, spice: 'Low' }
];
let nextId = 4;

// Helper functions
function sendSuccess(res, data, message, status = 200) {
  const response = { success: true };
  if (message) response.message = message;
  if (Array.isArray(data)) { response.count = data.length; response.data = data; }
  else { response.data = data; }
  return res.status(status).json(response);
}

function sendError(res, message, status = 400) {
  return res.status(status).json({ success: false, message });
}

// GET /biryani — Read all
router.get('/', (req, res) => {
  return sendSuccess(res, menu, 'Biryani menu loaded!');
});

// GET /biryani/:id — Read one
router.get('/:id', (req, res) => {
  const item = menu.find(b => b.id === Number(req.params.id));
  if (!item) return sendError(res, 'Biryani not found!', 404);
  return sendSuccess(res, item);
});

// POST /biryani — Create
router.post('/', (req, res) => {
  const { name, price, spice } = req.body;
  if (!name || !price) return sendError(res, 'Name and price required!', 400);

  const newItem = { id: nextId++, name, price: Number(price), spice: spice || 'Medium' };
  menu.push(newItem);
  return sendSuccess(res, newItem, 'Biryani added!', 201);
});

// PUT /biryani/:id — Update (full replacement)
router.put('/:id', (req, res) => {
  const id = Number(req.params.id);
  const index = menu.findIndex(b => b.id === id);
  if (index === -1) return sendError(res, 'Biryani not found!', 404);

  const { name, price, spice } = req.body;
  if (!name || !price) return sendError(res, 'Name and price required!', 400);

  menu[index] = { id, name, price: Number(price), spice: spice || menu[index].spice };
  return sendSuccess(res, menu[index], 'Biryani updated!');
});

// DELETE /biryani/:id — Delete
router.delete('/:id', (req, res) => {
  const id = Number(req.params.id);
  const index = menu.findIndex(b => b.id === id);
  if (index === -1) return sendError(res, 'Biryani not found!', 404);

  menu.splice(index, 1);
  return sendSuccess(res, null, 'Biryani deleted!');
});

export default router;

server.js — Mount the router:

import express from 'express';
import biryaniRoutes from './routes/biryani.routes.js';

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

// Mount the router at /biryani
app.use('/biryani', biryaniRoutes);

// 404 handler
app.use((req, res) => {
  res.status(404).json({ success: false, message: 'Route not found' });
});

// Error handler
app.use((err, req, res, next) => {
  console.error(err);
  res.status(500).json({ success: false, message: 'Server error' });
});

app.listen(3000);

This is exactly how production APIs are organized. Each resource gets its own router file. The server just mounts them.