<pre class="shiki github-dark shaku"><code>class Middleware { req; queue = []; /** * @param {MiddlewareFunc} func */ use(func) { this.queue.push(func); } /** * @param {Request} req */ start(req) { this.req = req; this.next(); } next = (err) =&gt; { try { const func = this.queue.shift(); if (!func) return; if (err &amp;&amp; func.length === 2) { this.next(err); return; } const params = [this.req, this.next]; func(...(func.length === 2 ? params : [err, ...params])); } catch (err) { this.next(err); } }}</code></pre>

Done

Have you ever used Express Middleware before? Middleware functions are functions with fixed interface that could be chained up like following two func…