proper usage of page store

src/lib/Link.svelte

@@ -1,26 +1,23 @@
-<script>
+<script context="module">
     import { page } from '$app/stores';
-    export let href;
-    let pageHost;
-    page.subscribe(p => pageHost = p.host); // apparently this works?
-
-    function isLocal(url) {
-        if (url.startsWith('/')) {
-            return true;
-        }
 
+    function host(url) {
         try {
-            let parsed = new URL(url);
-            return parsed.host === pageHost;
+            let u = new URL(url);
+            return u.host;
         }
         catch {
-            return false;
+            return null;
         }
     }
 </script>
 
+<script>
+    export let href;
+</script>
+
 <!-- we pass href explicitly so a11y doesn't scream at us -->
-{#if isLocal(href)}
+{#if href.startsWith('/') || host(href) === $page.host}
     <a sveltekit:prefetch {href} {...$$props}>
         <slot></slot>
     </a>