middleware-if-unless

import express from 'express'; import createIffUnless from 'middleware-if-unless'; const app = express(); interface CustomRequest extends express.Request { body: string; } const myMiddleware: express.RequestHandler = (req: CustomRequest, res, next) => { req.body = 'hit'; console.log('Middleware executed!'); next(); }; // Extend the middleware with iff/unless capabilities const extendedMiddleware = createIffUnless()(myMiddleware); // Use 'unless': middleware runs for all requests EXCEPT /not/allowed app.use(extendedMiddleware.unless([ '/not/allowed' ])); // Use 'iff': middleware runs ONLY for POST/PUT/DELETE/PATCH to /tasks/:id app.use(extendedMiddleware.iff([ { methods: ['POST', 'DELETE', 'PUT', 'PATCH'], url: '/tasks/:id', }, ])); app.get('/', (req: CustomRequest, res) => { res.send(`Root path. Middleware response: ${req.body ?? 'not hit'}`); }); app.get('/not/allowed', (req: CustomRequest, res) => { res.send(`Not Allowed path. Middleware response: ${req.body ?? 'not hit'}`); }); app.post('/tasks/123', (req: CustomRequest, res) => { res.send(`Task create. Middleware response: ${req.body ?? 'not hit'}`); }); const PORT = process.env.PORT ?? 3000; app.listen(PORT, () => { console.log(`Server listening on port ${PORT}`); console.log('Try:'); console.log(`- GET http://localhost:${PORT}/ (should show 'hit')`); console.log(`- GET http://localhost:${PORT}/not/allowed (should show 'not hit')`); console.log(`- POST http://localhost:${PORT}/tasks/123 (should show 'hit')`); });