A quick way to visit a random page on MDN

Maybe in the vein of Chris Coyier’s post on A /random Route on a WordPress Site, I found myself kinda interested in being able to just go to a random page on MDN. I didn’t find an obvious existing feature for this, so I hacked one together. It’s pretty simple — it fetches MDN’s sitemap, parses the XML, and grabs a random URL then redirects to it.

https://mdn-random.kkipp.workers.dev

I love Copilot for this kind of stuff. I had this thing built in less than 10 minutes. This Json2TS Raycast extension was also pretty helpful for generating TS interfaces for the parsed XML.

Here’s the complete code:

import xml2js from "xml2js";
export interface Env {}

interface Sitemap {
	urlset: Urlset;
}
interface Urlset {
	$: $;
	url: UrlItem[];
}
interface $ {
	xmlns: string;
}
interface UrlItem {
	loc: string[];
	lastmod: string[];
}

export default {
	async fetch(
		request: Request,
		env: Env,
		ctx: ExecutionContext,
	): Promise<Response> {
		const mdnSitemap = await fetch(
			"https://developer.mozilla.org/sitemaps/en-us/sitemap.xml.gz",
		);
		// parse xml sitemap
		const sitemapString = await mdnSitemap.text();
		const parsed = await (xml2js.parseStringPromise(
			sitemapString,
		) as Promise<Sitemap>);

		// pick a random url
		const randomIndex = Math.floor(Math.random() * parsed.urlset.url.length);
		const randomUrl = parsed.urlset.url[randomIndex].loc[0];

		// redirect to random url
		return new Response(null, {
			status: 302,
			headers: {
				Location: randomUrl,
			},
		});
	},
};