http-errors

import createError, { NotFound } from 'http-errors'; import express from 'express'; const app = express(); // Middleware to simulate authentication app.use((req, res, next) => { // For demonstration, let's assume a user is NOT logged in by default req.user = null; // or { id: 1, name: 'Test User' }; next(); }); app.get('/', (req, res, next) => { res.send('Welcome! Try navigating to /protected or /non-existent'); }); app.get('/protected', (req, res, next) => { if (!req.user) { // Create a 401 Unauthorized error return next(createError(401, 'Please login to view this page.')); } res.send(`Hello, ${req.user.name}! This is a protected page.`); }); app.get('/non-existent', (req, res, next) => { // Create a 404 Not Found error using a specific constructor next(new NotFound('The requested resource does not exist.')); }); // Catch-all for 404s that haven't been caught by other routes app.use((req, res, next) => { next(new NotFound(`Cannot ${req.method} ${req.originalUrl}`)); }); // Error handling middleware app.use((err, req, res, next) => { res.status(err.status || 500); res.json({ status: err.status, message: err.expose ? err.message : 'Internal Server Error' }); }); const PORT = process.env.PORT || 3000; app.listen(PORT, () => { console.log(`Server listening on port ${PORT}`); console.log(`Try: http://localhost:${PORT}/`); console.log(`Try: http://localhost:${PORT}/protected`); console.log(`Try: http://localhost:${PORT}/non-existent`); });