From a1fd1aee9cfefb656a0f6615ba28cfab6ca22e1c Mon Sep 17 00:00:00 2001
From: peterkogo <peter@xyflow.com>
Date: Wed, 3 Apr 2024 09:59:27 +0200
Subject: [PATCH] hidden nodes dont crash application on unmount anymore,
 hidden elements get correctly unobserved

---
 .../src/lib/components/NodeWrapper/NodeWrapper.svelte    | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/packages/svelte/src/lib/components/NodeWrapper/NodeWrapper.svelte b/packages/svelte/src/lib/components/NodeWrapper/NodeWrapper.svelte
index eff6c733..ad1cbc6e 100644
--- a/packages/svelte/src/lib/components/NodeWrapper/NodeWrapper.svelte
+++ b/packages/svelte/src/lib/components/NodeWrapper/NodeWrapper.svelte
@@ -58,7 +58,7 @@
   const nodeType = type || 'default';
 
   let nodeRef: HTMLDivElement;
-  let prevNodeRef: HTMLDivElement;
+  let prevNodeRef: HTMLDivElement | null = null;
 
   const nodeTypeValid = !!$nodeTypes[nodeType];
 
@@ -129,11 +129,16 @@
         resizeObserver?.observe(nodeRef);
         prevNodeRef = nodeRef;
       }
+    } else if (prevNodeRef) {
+      resizeObserver?.unobserve(prevNodeRef);
+      prevNodeRef = null;
     }
   }
 
   onDestroy(() => {
-    resizeObserver?.unobserve(nodeRef);
+    if (prevNodeRef) {
+      resizeObserver?.unobserve(prevNodeRef);
+    }
   });
 
   function onSelectNodeHandler(event: MouseEvent | TouchEvent) {