Enabling persisting notebook kernel information in notebooks

[mjbvz]

No description provided.

[mjbvz]

To test:

1. Using an extension with proposed api enabled
2. Try setting the kernelspec of the active notebook using the new api:

		const ext = vscode.extensions.getExtension('vscode.ipynb');
		const api = await ext?.activate();

		if (vscode.window.activeNotebookEditor) {
			api.setKernelSpec(vscode.window.activeNotebookEditor.document.uri, { test: 'bla' });
		}

3. Confirm document becomes dirty
4. Save
5. Now reopen the editor with the text editor and confirm that kernelspec is set

I've been testing this using the test.ipynb file in our repo

[mjbvz]

Hm, not sure this api is doing the correct thing after following those steps again.

Running against

vscode/extensions/vscode-api-tests/testWorkspace/test.ipynb

Line 2 in 1d8a91d

"cells": [

, results in:

{
 "cells": [ ...
]
 "metadata": {
  "interpreter": {
   "hash": "815c6b7592bf74925ca002a1774bcf064bae9d6a27e7933fd9109275fb484258"
  },
  "kernelspec": {
   "name": "python3",
   "display_name": "Python 3.9.5 64-bit ('myvenv': venv)"
  },
  "language_info": {
   "codemirror_mode": {
    "name": "ipython",
    "version": 3
   },
   "file_extension": ".py",
   "mimetype": "text/x-python",
   "name": "python",
   "nbconvert_exporter": "python",
   "pygments_lexer": "ipython3",
   "version": "3.9.5"
  }
 },
 "nbformat": 4,
 "nbformat_minor": 4,
 "kernelspec": {
  "test": "bla"
 }
}

The notebook should also be marked dirty after its metadata is changed. It currently is not

@roblourens @jrieken Are you more familiar with the notebook editing api? Is it expected that replaceNotebookMetadata would not mark the targeted notebook as dirty?

[jrieken]

@roblourens @jrieken Are you more familiar with the notebook editing api? Is it expected that replaceNotebookMetadata would not mark the targeted notebook as dirty?

It depends on the notebook serializer - they can mark what metadata is transient and what is persisted. This is how it is defined for our ipynb extension:

vscode/extensions/ipynb/src/ipynbMain.ts

Line 11 in 1dae051

context.subscriptions.push(vscode.workspace.registerNotebookSerializer('jupyter-notebook', serializer, {

[mjbvz]

@roblourens @DonJayamanne Pushed b2bbd76 that writes the kernelspec into the metadata.kernelspec in the ipynb file. I have to admit I don't understand what is going on with the custom property or where the kernelspec needs to be, but this seems to align with how the kernelspec is written in existing notebooks

Also, I believe the ipynb serializer does not set transientDocumentMetadata so all metadata should be non-transient, however writing the new metadata still doesn't mark the notebook as dirty. Still looking into this

[mjbvz]

I believe this line is why the notebook document is never marked dirty:

vscode/src/vs/workbench/contrib/notebook/common/model/notebookTextModel.ts

Line 664 in 62bfac1

if (key !== 'trusted') {

I don't really understand what it is doing but it always returns true when I tru updating the custom metadata

[DonJayamanne]

n't understand what is going on with the custom property or where the kernelspec needs t

In the past all custom notebook metadata had to be set in a property named custom (within the notebook metadata object). this is the API that was exposed to extension authors. Later the API was changed to allow extension authors to store anything within the metadata object. I.e. metadata was completely for extension authors.

Unfortunately by that time .NET team and Jupyter team was already relying on custom to be the place where jupyter notebook metadata would be stored/accessed from.

The plan is to move away from that custom property, however we'd have to let others know about this change (else it could just break .NET, jupyter extensions).
I think we should do this in debt week & submit PRs to the relevant extension so that they can migrate to a path without using custom.

[mjbvz]

Fixed by #131681 and ported to the release branch

See original verification steps: #130602 (comment)