fix: allow store as initial value for props in ssr (#12885)

.changeset/smart-poets-care.md

@@ -0,0 +1,5 @@
+---
+'svelte': patch
+---
+
+fix: allow store as initial value for props in ssr

packages/svelte/src/compiler/phases/3-transform/server/visitors/VariableDeclaration.js

@@ -39,7 +39,9 @@ export function VariableDeclaration(node, context) {
 						}
 					}
 				});
-				declarations.push(b.declarator(id, b.id('$$props')));
+				declarations.push(
+					b.declarator(/** @type {Pattern} */ (context.visit(id)), b.id('$$props'))
+				);
 				continue;
 			}
 

packages/svelte/tests/server-side-rendering/samples/store-init-props/_config.js

@@ -0,0 +1,3 @@
+import { test } from '../../test';
+
+export default test({});

packages/svelte/tests/server-side-rendering/samples/store-init-props/_expected.html

@@ -0,0 +1 @@
+1

packages/svelte/tests/server-side-rendering/samples/store-init-props/main.svelte

@@ -0,0 +1,7 @@
+<script lang="ts">
+	import { writable } from 'svelte/store';
+	const page = writable(1);
+	const { value = $page } = $props();
+</script>
+
+{value}