Switch to ruff for formatting (#235)

Makefile

@@ -10,10 +10,12 @@ help:
 test:  ## Run tests, linting, and static typechecking
 	tox
 
+.PHONY: format
+format:  ## Format files
+	tox exec -e py38-lint -- ruff format
+
 .PHONY: lint
-lint:  ## Lint and black reformat files
-	# NOTE(willkg): Make sure this matches what's in tox.ini.
-	black src setup.py tests docs examples
+lint:  ## Lint files
 	tox -e py38-lint
 
 .PHONY: clean

pyproject.toml

@@ -2,22 +2,18 @@
 # Enable pycodestyle (E), pyflakes (F), and bugbear (B) rules
 select = ["E", "F", "B"]
 
-# Ignore line length violations--Black handles those
+# Ignore line length violations
 line-length = 88
 ignore = ["E501"]
 
-target-version = "py37"
+target-version = "py38"
 
 src = ["src"]
 
 [tool.ruff.flake8-quotes]
 docstring-quotes = "double"
 
 
-[tool.black]
-line-length = 88
-target-version = ["py38"]
-
 [tool.mypy]
 python_version = "3.8"
 disallow_untyped_defs = true
@@ -75,8 +71,8 @@ commands = pytest --doctest-modules src/
 basepython = python3.8
 changedir = {toxinidir}
 commands =
-    black --diff setup.py tests docs examples
-    ruff src setup.py tests docs examples
+    ruff format --check setup.py tests docs examples
+    ruff check src setup.py tests docs examples
 
 [testenv:py38-typecheck]
 basepython = python3.8

requirements-dev.txt

@@ -1,13 +1,12 @@
 # Requirements file for developing on Everett.
 -e .[ini,yaml,sphinx]
 
-black==23.9.1
 check-manifest==0.49
 cogapp==3.3.0
-mypy==1.5.1
-pytest==7.4.2
-ruff==0.0.292
-tox==4.11.3
+mypy==1.8.0
+pytest==7.4.3
+ruff==0.1.9
+tox==4.11.4
 tox-gh-actions==3.1.3
 twine==4.0.2
 types-PyYAML==6.0.12.12