From b35531bbaf5fd855d6fcedf3abcddb62180beabe Mon Sep 17 00:00:00 2001
From: Damian Pieczynski <piecyk@gmail.com>
Date: Fri, 23 Aug 2024 13:26:05 +0200
Subject: [PATCH] fix: getItemKey when element is missing from list

---
 packages/virtual-core/src/index.ts | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/packages/virtual-core/src/index.ts b/packages/virtual-core/src/index.ts
index c3bec65b..42d0b791 100644
--- a/packages/virtual-core/src/index.ts
+++ b/packages/virtual-core/src/index.ts
@@ -727,8 +727,11 @@ export class Virtualizer<
     entry: ResizeObserverEntry | undefined,
   ) => {
     const index = this.indexFromElement(node)
-    const key = this.options.getItemKey(index)
-
+    const item = this.measurementsCache[index]
+    if (!item) {
+      return
+    }
+    const key = item.key
     const prevNode = this.elementsCache.get(key)
 
     if (prevNode !== node) {