Extend config from a remote TOML

[yoann9344]

It would be nice to be able to extend the config from a main project on another git.

[tool.ruff]
extend = "../ruff/pyproject.toml"
# instead we could write something like this :
extend = { git = "https://github.com/astral-sh/ruff.git", tag="0.2.1" }
extend = { git = "https://github.com/astral-sh/ruff.git", branch="some_branch" }
# maybe with the possibility to configure the path to the `pyproject.toml`
extend = { git = "https://github.com/astral-sh/ruff.git", tag="0.2.1", path = "my_dir_configs/pyproject.toml" }

Could even imagine to retrieve a config from a dependency manager like pep compliant or poetry :

[project]
dependencies = [
    "my-repo @ git+https://github.com/my-repo/[email protected]"
]
[tool.poetry.dependencies]
my-repo = { git = "https://github.com/my-repo/ruff.git", tag="0.2.1" }

[tool.ruff]
extend = { pep = "my-repo", path = "my_dir_configs/pyproject.toml" }
extend = { poetry = "my-repo", path = "my_dir_configs/pyproject.toml" }

The logic behind will basically do something like this :

# With default values :
# extend_tag=""
# extend_branch=""
# extend_path="pyproject.toml"
position=`pwd`
git clone --no-checkout --depth=1 --no-tags $extend_git $somewhere_in_ruff_cache
cd $somewhere_in_ruff_cache
if [ "$extend_tag" != "" ]; then
    git fetch origin "+refs/tags/${extend_tag}:refs/tags/${extend_tag}" --no-tags
    git checkout $extend_tag -- $extend_path
else
    git checkout $extend_branch -- $extend_path  # empty branch is HEAD
fi
cd $position
# config ruff to point on the retrieved toml
config_extend "${somewhere_in_ruff_cache}/${extend_path}"

[MichaReiser]

Thanks for the excellent write up. Yes, we want to support this but haven't had the time to fully design it yet. You can subscribe to #809 to keep updated on the work