Express.js v5

Here are the key changes in Express.js v5:

1. Automatic async error handling No need for explicit try/catch blocks Errors automatically forwarded to error middleware

2. Updated method signatures Deprecated: res.json(obj, status) New: res.status(200).json({}) res.send(status) replaced with res.sendStatus()

3. Pluralized request methods acceptsCharset → acceptsCharsets acceptsEncoding → acceptsEncodings acceptsLanguage → acceptsLanguages

4. Removed deprecated features req.param() removed res.sendfile renamed to res.sendFile()

5. Route matching changes New wildcard syntax: /path/*splat RegExp route patterns removed Multiple explicit routes needed instead

6. Enforced async template rendering res.render() is now strictly asynchronous

===================================================== ================= Async Error Handling ==================== // V4 app.get('/user/:id', async (req, res, next) => { try { const user = await User.findById(req.params.id); res.json(user); } catch (err) { next(err); } });

// V5 - Simpler app.get('/user/:id', async (req, res) => { const user = await User.findById(req.params.id); res.json(user); });

================= Method Signatures ==================== // V4 res.json({ message: 'OK' }, 200); res.send(200);

// V5 res.status(200).json({ message: 'OK' }); res.sendStatus(200);

================= Parameter Access ==================== // V4 const id = req.param('id');

// V5 const id = req.params.id; const queryId = req.query.id; const bodyId = req.body.id;

================= Route Patterns ==================== // V4 app.get('/(page|discussion)/:slug', handler);

// V5 app.get(['/page/:slug', '/discussion/:slug'], handler);

================= Wildcard Routes ==================== // V4 app.get('/path/*', handler);

// V5 app.get('/path/*splat', handler);