From 4f1063723e9ca0d10bc57592086ddd90e98911be Mon Sep 17 00:00:00 2001
From: mimbrown <mimbrown94+git@gmail.com>
Date: Thu, 15 Jun 2023 01:03:17 +0530
Subject: [PATCH] fix: Don't break in `attributeChangedCallback` if
 `$$component` does not exist yet (#8701)

Since the custom element class waits one tick before instantiating the `$$component` field, it's possibly undefined when `attributeChangedCallback` is called.
---
 packages/svelte/src/runtime/internal/Component.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/svelte/src/runtime/internal/Component.js b/packages/svelte/src/runtime/internal/Component.js
index 4512b3ab35f8..878251e08a38 100644
--- a/packages/svelte/src/runtime/internal/Component.js
+++ b/packages/svelte/src/runtime/internal/Component.js
@@ -287,7 +287,7 @@ if (typeof HTMLElement === 'function') {
 				this.$$props_definition,
 				'toProp'
 			);
-			this.$$component.$set({ [attr]: this.$$data[attr] });
+			this.$$component?.$set({ [attr]: this.$$data[attr] });
 		}
 
 		disconnectedCallback() {