Ruff, linter dependencies, full check config

By default, the command `darker` now runs Black on the source code of
Darker, the Darker GitHub Action, release tooling and `setup.py`.

`--config=check-darker.toml` can now be used to run Flake8, Mypy,
Pydocstyle, Pylint and Ruff on modified lines in above mentioned files.
Those tools are included when installing with the `[test]` extra.

The minimum ruff version is now 0.0.292, and its configuration in
`pyproject.toml` has been updated accordingly.

check-darker.toml

@@ -0,0 +1,33 @@
+# This is the Darker configuration file for running all the code formatters and linters
+# on the Darker code base. To use it, run:
+#   $ darker --config=check-darker.toml
+
+[tool.black]
+# Darker makes Black read its configuration from the file indicated by the `--config`
+# option, so we need to mirror the same configuration here and in `pyproject.toml`.
+skip-string-normalization = false
+target-version = ["py311"]
+
+[tool.isort]
+# Darker makes isort read its configuration from the file indicated by the `--config`
+# option, so we need to mirror the same configuration here and in `pyproject.toml`.
+profile = "black"
+known_first_party = ["darkgraylib", "graylint"]
+known_third_party = ["pytest"]
+
+[tool.darker]
+src = [
+    "action",
+    "release_tools",
+    "src",
+    "setup.py",
+]
+revision = "origin/master..."
+isort = true
+lint = [
+    "flake8",
+    "mypy",
+    "pydocstyle",
+    "pylint",
+    "ruff check",
+]

pyproject.toml

@@ -3,22 +3,52 @@
 requires = ["setuptools", "wheel"]  # PEP 508 specifications.
 
 [tool.black]
+# Darker makes Black read its configuration from the file indicated by the `--config`
+# option, so we need to mirror the same configuration here and in `check-darker.toml`.
 skip-string-normalization = false
 target-version = ["py311"]
 
 [tool.isort]
+# Darker makes isort read its configuration from the file indicated by the `--config`
+# option, so we need to mirror the same configuration here and in `check-darker.toml`.
 profile = "black"
 known_first_party = ["darkgraylib", "graylint"]
 known_third_party = ["pytest"]
 
 [tool.darker]
+# Only minimal options for Darker by default, so it's easier to test while developing.
+# To check Darker's own code base with the full set of reformatters and linters, use:
+#   $ darker --config=check-darker.toml
 src = [
     "action",
+    "release_tools",
     "src",
+    "setup.py",
 ]
 revision = "origin/master..."
 
 [tool.pylint."messages control"]
 # Check import order only with isort. Pylint doesn't support a custom list of first
 # party packages. We want to consider "darkgraylib" and "graylint" as first party.
 disable = ["wrong-import-order"]
+
+[tool.ruff]
+target-version = "py38"
+
+[tool.ruff.lint]
+select = ["ALL"]
+ignore = [
+    "ANN101",  # Missing type annotation for `self` in method
+    "D203",  # One blank line required before class docstring
+    "D213",  # Multi-line docstring summary should start at the second line
+    "D400",  # First line should end with a period (duplicates D415)
+]
+
+[tool.ruff.lint.per-file-ignores]
+"src/darker/tests/*.py" = [
+    "ANN001",  # Missing type annotation for function argument
+    "ANN201",  # Missing return type annotation for public function
+    "ANN204",  # Missing return type annotation for special method `__init__`
+    "C408",  # Unnecessary `dict` call (rewrite as a literal)
+    "S101",  # Use of `assert` detected
+]

setup.cfg

@@ -60,13 +60,16 @@ test =
     mypy>=0.990
     pathspec  # to test `gen_python_files` in `test_black_diff.py`
     pip-requirements-parser
+    pydocstyle
     pygments
+    pylint
     pytest>=6.2.0
     pytest-darker
     pytest-kwparametrize>=0.0.3
     regex>=2021.4.4
     requests_cache>=0.7
     ruamel.yaml>=0.17.21
+    ruff>=0.0.292
     twine>=2.0.0
     types-requests>=2.27.9
     types-toml>=0.10.4