Notebook dirty flag is not reset when it is re-opened

[3coins]

Screen.Recording.2025-05-21.at.11.19.04.AM.mov

[dlqqq]

PR #51 may have introduced this bug because we no longer save the Jupyter YDoc when dirty gets set to False. I thought the frontend was reading from the YDoc state (which is still updated when setting dirty=False), but this may not be right.

One solution to explore is to write when dirty=False only if dirty=True previously. I think there's a way to check this.

[dlqqq]

Weird, this only happens for notebooks but not for text files. My earlier hypothesis might be wrong since I don't see a reason that would only break for notebooks.

[dlqqq]

Hmm, I added a log to check the status of the dirty flag in the YRoomFileAPI._watch_file() loop, and it shows that dirty=False always:

[E 2025-05-30 13:52:55.584 ServerDocsApp] False
[E 2025-05-30 13:52:56.087 ServerDocsApp] False
...

But, weirdly, it does hide the dirty indicator after making an update through the UI. 🤔 This seems to show:

• The UI doesn't just rely on jupyter_ydoc.dirty to show the unsaved changes icon,
• Saving the YDoc somehow fixes the issue. Not sure if this is caused by the file save itself or if it is caused by setting dirty=False again even if it's already False.

[dlqqq]

Accidentally closed by a commit message. This issue still exists after an out-of-band change was made to the notebook.

I did some research and figured out why this is the case. When the UI sets dirty=True, this does not update the ydoc.state dictionary that the backend uses. So the backend has no way of setting dirty=False in response. The jupyter_collaboration implementation seems to rely on the backend constantly setting dirty=False in order to keep this icon hidden, instead of letting the backend ensure dirty=False is always set by updating it when dirty=True.

[dlqqq]

Basically, the solution is to override NotebookModel to use ydoc.state as a single source of truth regarding the 'dirty' state, instead of having separate de-synchronized dirty states in the frontend & backend. I have a plan for fixing this, so I'll assign myself to this issue. 👍

[ellisonbg]

@Zsailer is this one fixed?