Support for VS Code Jupyter Notebooks

[kv9898]

Currently, air formats plain R documents like a charm! But it does bot format R code cells in .ipynb files. Can we add support for this?

[lionel-]

Unfortunately that is out of scope for Air. The extension managing the ipynb files should have its own formatter that delegates to the language-specific formatters.

[lionel-]

Sorry I closed this too fast. After researching the issue more, I found that:

1. With the CLI we could format notebooks tagged with R, or notebook cells tagged with R.

2. With the LSP, we could have specific support for vscode-notebook and vscode-notebook-cell URIs, as you have already noted in Support R chunk formatting in Jupyter/Positron notebooks #432.

Relevant links from ruff:

• CLI dispatch for notebook
  https://github.com/astral-sh/ruff/blob/main/crates/ruff/src/commands/format.rs#L407-L424

• Server handler for notebook
  https://github.com/astral-sh/ruff/blob/6271fba1e1c01c9c49a360b1084217955145bce6/crates/ruff_server/src/server/api/requests/format.rs#L42-L53

• Notebook deserialiser and cell parser:
  https://github.com/astral-sh/ruff/blob/main/crates/ruff_notebook/src/notebook.rs

• Document data structure for a single cell:
  https://github.com/astral-sh/ruff/blob/6271fba1e1c01c9c49a360b1084217955145bce6/crates/ruff_server/src/edit/notebook.rs#L25-L29

• Extension URI selectors:
  https://github.com/astral-sh/ruff-vscode/blob/f0b48ed6e7bbfbdf41067a5471538d884184659f/src/common/utilities.ts#L44-L45