Format cell adds blank line at the end

[memeplex]

Environment data

• VS Code version: 1.61.2
• Jupyter Extension version (available under the Extensions sidebar): v2021.9.1101343141
• Python Extension version (available under the Extensions sidebar): v2021.11.1422169775
• OS (Windows | Mac | Linux distro) and version: macOS Big Sur
• Python and/or Anaconda version: 3.9.7
• Type of virtual environment used (N/A | venv | virtualenv | conda | ...): venv
• Jupyter server running: Local

Expected behaviour

If I format a cell using black no blank line is added at the end of the cell.

Actual behaviour

A blank line is added at the end of the cell.

Steps to reproduce:

[NOTE: Self-contained, minimal reproducing code samples are extremely helpful and will expedite addressing your issue]

1. Configure black as formatter.
2. Create a note with a cell with x = 1 as content.
3. From the context menu for the cell, select Format cell.

[memeplex]

Maybe it's not that a blank line is added at the end but that a newline is added to the last line. Anyway, that might be ok for a python file but it's undesirable for a cell, it's a lot of wasted space having what, at least visually, is a blank line in each cell of a notebook.

[rchiodo]

Cell formatting is actually handled by the python extension (cells are considered python documents). Transferring issue there.

[memeplex]

I don't think that approach would work OOTB, I've seen problems with it in Jupyter Lab extensions as well, cells have their own quirks, for example you don't want a newline at the end of a cell.

[memeplex]

Perhaps one should use a formatter that supports selection format, instead of black (as in my case).

[karthiknadig]

This should be handled when we move formatting over LSP. Closing in favor of #17918