feat: create robots.txt programmatically

src/routes/robots.txt/+server.ts

@@ -0,0 +1,51 @@
+import { siteConfig } from '$lib/config/site';
+
+const SITE_URL = siteConfig.url;
+
+/**
+ * SvelteKit RequestHandler for generating robots.txt.
+ */
+export async function GET() {
+	// Define the robots.txt configuration
+	const robotsConfig = [
+		{
+			agent: '*',
+			disallow: ['/']
+		}
+	];
+
+	const body = generateRobotsTxt(SITE_URL, robotsConfig);
+
+	return new Response(body, {
+		headers: {
+			'Cache-Control': `public, max-age=${86400}`, // 24 hours
+			'Content-Type': 'text/plain' // Corrected MIME type for robots.txt
+		}
+	});
+}
+
+/**
+ * Generates robots.txt content.
+ * @param {string} siteUrl Base site URL.
+ * @param {Array} config Robots.txt configuration array.
+ * @returns {string} robots.txt content.
+ */
+function generateRobotsTxt(siteUrl: string, config: { agent: string; disallow: string[] }[]) {
+	return `Sitemap: ${siteUrl}/sitemap.xml
+
+# https://developers.google.com/search/docs/advanced/sitemaps/build-sitemap#addsitemap
+# https://www.robotstxt.org/robotstxt.html
+${config.map((item) => generateRobotsTxtAgent(item.agent, item.disallow)).join('\n')}
+`;
+}
+
+/**
+ * Generates a user-agent section for robots.txt.
+ * @param {string} agent User-agent string.
+ * @param {string[]} disallow Array of paths to disallow.
+ * @returns {string} User-agent section of robots.txt.
+ */
+function generateRobotsTxtAgent(agent: string, disallow: string[]) {
+	const disallowEntries = disallow.map((path) => `Disallow: ${path}`).join('\n');
+	return `User-agent: ${agent}\n${disallowEntries}`;
+}