Currently there is no way to provide diffs at the notebook level. We currently receive notebook changes in the form of notebook synchronization events.

The Notebook features that are available from TS APIs like WorkspaceEdit.set is currently not exposed to Language Servers. Having this will allow language servers to perform notebook level "formatting" (restructuring), refactoring, insert/delete/re-order cells.

Adding NotebookEdit support can generally allow updating notebooks via formatting, code action, or any request.

Notes:

• We will need to add NotebookEdit to WorkspaceEdit, and also introduce a NotebookCellData type since the NotebookCell type is not sufficient to create new cells.
• Core WorkspaceEdit API supports NotebookEdit : https://github.com/microsoft/vscode/blob/29e000b1e5c03e7c9a6fccf3e475f0b5a239e4d6/src/vscode-dts/vscode.d.ts#L3967
• NotebookCellData : https://github.com/microsoft/vscode/blob/29e000b1e5c03e7c9a6fccf3e475f0b5a239e4d6/src/vscode-dts/vscode.d.ts#L14869-L14911

ref: microsoft/vscode#204544