modern support to robot.txt

Author: Alessandro100

public/robots.staging.txt

@@ -14,6 +14,9 @@ import { Container } from '@mui/material';
 export const metadata = {
   title: 'Mobility Database',
   description: 'Mobility Database',
+  robots: process.env.VERCEL_ENV === 'production'
+    ? 'index, follow'
+    : 'noindex, nofollow',
 };
 
 const mulish = Mulish({

public/robots.txt

@@ -0,0 +1,16 @@
+import { type MetadataRoute } from 'next';
+
+export default function robots(): MetadataRoute.Robots {
+  const isProd = process.env.VERCEL_ENV === 'production';
+
+  return {
+    rules: [
+      {
+        userAgent: '*',
+        allow: isProd ? '/' : '',
+        disallow: isProd ? '' : '/',
+      },
+    ],
+    sitemap: isProd ? 'https://mobilitydatabase.org/sitemap.xml' : undefined,
+  };
+}