basic-middleware-server.js

const http = require('http');
const path = require('path');
const fs = require('fs');
const port = process.env.PORT || 8080;
const host = process.env.HOST || '0.0.0.0';
const publicPath = __dirname;

function serveStatic(publicPath) {
	return function(request, response) {
		let url = '.' + request.url;

    // TODO: Should stat for directory listing.
    if (!fs.existsSync(url)) {
			response.statusCode = 404;
			response.end();
			return;
		}

		console.log('Found:', url);
		fs.readFile(url, 'utf-8', (err, data) => {
			if (err) {
				response.statusCode = 500;
				response.end();
				return;
			}

			response.statusCode = 200;
			response.end(data);
		});
	}
}

const app = (function connect() {
	let middlewares = [];

	return {
		use(fn) {
			middlewares.push(fn);
		},
		listen(port, host) {
			const server = http.createServer(function connected(request, response) {
				console.log(middlewares.length);
				if (middlewares.length === 0) {
					console.error('You need to define at least one middleware...');
					process.exit(1);
					return;
				}
				middlewares.reduce((previous, current) => {
					return (req, res, next = function() {}) => previous(req, res, current)
				})(request, response)
			});
			server.listen(port, host);
		}
	};
})()

app.use(serveStatic(publicPath));
app.listen(port, host)
console.log('Serving files from ' + publicPath);
console.log('server started on ' + host + ':' + port)