Koa.js 404 Middleware Example - Koa-js Typing CST Test
Loading…
Koa.js 404 Middleware Example — Koa-js Code
Middleware example to handle 404 responses.
const Koa = require('koa');
const app = new Koa();
app.use(ctx => {
ctx.status = 404;
ctx.body = { error: 'Not Found' };
});
app.listen(3000, () => {
console.log('Server running on http://localhost:3000');
});Koa-js Language Guide
Koa.js is a modern, minimalist web framework for Node.js, created by the same team behind Express.js. It leverages async/await for clean middleware handling and provides a lightweight foundation for building APIs and web applications.
Primary Use Cases
- ▸Building RESTful APIs with async/await middleware
- ▸Small to medium web application backends
- ▸Microservices requiring modular architecture
- ▸Integration with custom routing and authentication solutions
- ▸Prototyping fast and lightweight Node.js servers
Notable Features
- ▸Minimal and lightweight core
- ▸Async/await middleware chaining
- ▸Full control over request and response objects
- ▸Modular design, easily extended with npm packages
- ▸High performance due to small overhead
Origin & Creator
Koa.js was created by the Express.js team-TJ Holowaychuk and contributors-in 2013-2014 as a next-generation, lightweight framework for Node.js.
Industrial Note
Koa is preferred when developers want minimalism, async/await-based middleware, and full control over application structure without opinionated conventions.