Add deprecation warning

[dhruvmanila]

Summary

This PR adds a deprecation warning during the initialization request if the ruff executable found is >= 0.3.5.

Refer to #520 (comment) for the discussion.

Preview

VS Code

It'll provide a warning notification along with logging the message:

Neovim

It seems like Neovim has already deprecated ruff_lsp if the user is using nvim-lspconfig (which should be most of the users):

But, regardless, the users should receive the warning if they've configured it to do so:

[MichaReiser]

I'm a bit worried by the churn the deprecation creates. Should we provide an opt-out option for now (setting) to silence the warning, then remove the option in a follow up release (0.10.x) and remove support entirely in 0.11.x?

[dhruvmanila]

I'm a bit worried by the churn the deprecation creates. Should we provide an opt-out option for now (setting) to silence the warning, then remove the option in a follow up release (0.10.x) and remove support entirely in 0.11.x?

Hmm, I see. Does this mean that by default there will be no warning but if the user de-select this option, they'll receive this warning?

[MichaReiser]

Hmm, I see. Does this mean that by default there will be no warning but if the user de-select this option, they'll receive this warning?

I'd enable it by default, but give users an option to opt-out. But I'm not sure if it is worth it. I'm just trying to think trough approaches on how we could de-risk the deprecation by reducing possible churn. On the other hand, showing the deprecation only on start doesn't seem too bad.

[dhruvmanila]

I'd enable it by default, but give users an option to opt-out. But I'm not sure if it is worth it. I'm just trying to think trough approaches on how we could de-risk the deprecation by reducing possible churn. On the other hand, showing the deprecation only on start doesn't seem too bad.

Yeah, I'm not sure if it's worth it. There's the issue that the option itself would need to go through a deprecation period of the sorts.

[dhruvmanila]

Re #520 (comment), here's how I tested it:

Installed Ruff 0.3.4 via uv tool install [email protected] and got no deprecation warning and the following logs:

Client logs:

025-02-06 15:22:41.619 [info] Using the Ruff binary: /Users/dhruv/.local/bin/ruff
2025-02-06 15:22:41.662 [info] Stable version of the native server requires Ruff 0.5.3, but found 0.3.4 at /Users/dhruv/.local/bin/ruff instead
2025-02-06 15:22:41.662 [info] Resolved 'ruff.nativeServer: auto' to use the legacy (ruff-lsp) server
2025-02-06 15:22:41.665 [info] Server run command: /Users/dhruv/playground/ruff/.venv/bin/python /Users/dhruv/work/astral/ruff-vscode/bundled/tool/server.py
2025-02-06 15:22:41.665 [info] Server: Start requested.

Server logs:

Interpreter executable (/Users/dhruv/playground/ruff/.venv/bin/ruff) not found
Using environment executable: /Users/dhruv/.local/bin/ruff
Inferred version 0.3.4 for: /Users/dhruv/.local/bin/ruff
Found ruff 0.3.4 at /Users/dhruv/.local/bin/ruff
Interpreter executable (/Users/dhruv/playground/ruff/.venv/bin/ruff) not found
Using environment executable: /Users/dhruv/.local/bin/ruff
Found ruff 0.3.4 at /Users/dhruv/.local/bin/ruff
Running Ruff with: /Users/dhruv/.local/bin/ruff ['check', '--force-exclude', '--no-cache', '--no-fix', '--quiet', '--output-format', 'json', '-', '--stdin-filename', '/Users/dhruv/playground/ruff/lsp/play.py']

And, upgraded the Ruff version to make sure I still get the warnings.