Test Persistence and Data Transfer

Now test the features that keep the application useful after the current page session.

1. Create and modify several tasks.
2. Change the task order.
3. Change the theme.
4. Refresh the page.
5. Confirm that your tasks, ordering, and preference are restored.
6. Export the tasks as JSON.
7. Import the exported file again.
8. Confirm that the imported tasks appear correctly.

Also test an invalid or incomplete JSON file and confirm that the application does not replace valid task data with unusable content.

Checkpoint

Your task data survives a refresh and can be exported and restored successfully.