This notebooks shows how a warning and an error is raised when there is no title in the first cell.

from nbproject import header, meta, publish
import pytest

header()
idaK1IQUYIQsMs
version0
time_init2022-06-08 14:42
time_run2024-05-20 09:46
pypackage_storenbproject==0.0.7+2.g8521e30
pypackage_livenbproject==0.10.3 pytest==8.2.1
meta.live.title  # returns None
publish() == "no-title"
❌ No title! Update & save your notebook with a title '# My title' in the first cell.
True