Backport PR #7567: Fix undefined error when checkpoints is empty (#7568)

meeseeksmachine · jdavid · web-flow · commit 45094d9521ee · 2025-01-24T12:48:18.000+01:00
Co-authored-by: J. David Ibáñez &lt;jdavid.ibp@gmail.com&gt;
diff --git 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];

Original file line number	Diff line number	Diff line change
`@@ -124,7 +124,7 @@ const checkpoints: JupyterFrontEndPlugin<void> = {`
`124`	`124`	`context?.fileChanged.connect(onChange);`
`125`	`125`
`126`	`126`	`const checkpoints = await context?.listCheckpoints();`
`127`		`- if (!checkpoints) {`
	`127`	`+ if (!checkpoints \|\| !checkpoints.length) {`
`128`	`128`	`return;`
`129`	`129`	`}`
`130`	`130`	`const checkpoint = checkpoints[checkpoints.length - 1];`