Adds ruff and mypy linting and type checking

[Mbeaulne]

Summary

• Replace Black with Ruff for linting and formatting.

Why Ruff over Black?

Ruff is a single tool that replaces Black (formatting), flake8 (linting), isort (import sorting), and pyupgrade (syntax modernization) -- all in one. It's written in Rust and runs 10-100x faster than the tools it replaces. Rather than maintaining separate configs and dependencies for each tool, Ruff handles everything through a single [tool.ruff] section in pyproject.toml.

To test this tool run the following command (note: all linting fixes are in the PR above):

uv run ruff check --fix . && uv run ruff format .

[Mbeaulne]

• Fixes typing issues using mypy #122
• run ruff on codebase #121
• Adds ruff and mypy linting and type checking #120 👈 (View in Graphite)
• master

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[morgan-wowk]

For the uv.lock changes, it might be worth researching why this was needed.

I am not sure if it's a NOOP change but it seems like the type of thing where one developer's environment will want to write the UV file using one version of this, and another developer will use a different version, causing constant (and longer than necessary) changes to the file.

[morgan-wowk]

Perhaps ☝️ will lead to a much shorter change to the uv.lock if we can eliminate whatever decided to do that change

[morgan-wowk]

Would you mind putting together some instructions for how developers should set up their editor to use ruff instead of black?

Right now, if I right click a document and select "Format Document" my understanding is that it formats the document using Black. I also have the cursor extension "Black Formatter" installed and assume after this myself and others would be recommended to uninstall it. That just leaves me wondering what other steps we would need to take to fully adopt ruff in our editor in place of black.

[Ark-kun]

Right now, if I right click a document and select "Format Document" my understanding is that it formats the document using Black. I also have the cursor extension "Black Formatter" installed

yes. We're using Black for backend code formatting.

[Mbeaulne]

I propose moving from Black to Ruff for both linting and formatting. Ruff's formatter is Black-compatible (same output, just ~100x faster), and gives you linting + formatting from a single tool.

Steps

1. Uninstall the "Black Formatter" extension
2. Install the Ruff extension (by Astral)
3. Update your settings — add the following to your Cursor/VS Code settings (Cmd+Shift+P → "Preferences: Open Settings (JSON)"):

"[python]": {
"editor.defaultFormatter": "charliermarsh.ruff",
"editor.formatOnSave": true
}