From 8b3b5b3ce7e421074ee71de007f89a87a1c01697 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=2E=20David=20Ib=C3=A1=C3=B1ez?= <jdavid.ibp@gmail.com>
Date: Fri, 24 Jan 2025 11:59:26 +0100
Subject: [PATCH] Fix undefined error when checkpoints is empty (#7567)

---
 packages/notebook-extension/src/index.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/notebook-extension/src/index.ts b/packages/notebook-extension/src/index.ts
index b43e622e19..cd9d9752d1 100644
--- a/packages/notebook-extension/src/index.ts
+++ b/packages/notebook-extension/src/index.ts
@@ -124,7 +124,7 @@ const checkpoints: JupyterFrontEndPlugin<void> = {
       context?.fileChanged.connect(onChange);
 
       const checkpoints = await context?.listCheckpoints();
-      if (!checkpoints) {
+      if (!checkpoints || !checkpoints.length) {
         return;
       }
       const checkpoint = checkpoints[checkpoints.length - 1];