switched to ruff for linting

Makefile

@@ -29,6 +29,9 @@ BROWSER := python -c "$$BROWSER_PYSCRIPT"
 help:
 	@python -c "$$PRINT_HELP_PYSCRIPT" < $(MAKEFILE_LIST)
 
+venvexists:  ## helper to check if a virtual environment exists
+	@test -x .venv/bin/python || { echo "No virtual environment found, please run 'make devenv'"; exit 1; }
+
 clean: clean-build clean-pyc clean-test ## remove all build, test, coverage and Python artifacts
 
 clean-build: ## remove build artifacts
@@ -50,44 +53,36 @@ clean-test: ## remove test and coverage artifacts
 	rm -f .coverage
 	rm -fr htmlcov/
 
-lint: ## reformat with black and check style with flake8
-	isort ordr3
-	isort tests
-	black ordr3 tests
-	flake8 ordr3 tests
-
-test: lint ## run tests quickly, stop on first error
-	pytest tests -x -l --last-failed --disable-warnings -m "not fun"
-
-testfun: lint ## run functional tests, stop on first error
-	pytest tests -x -l -m "fun"
+lint: venvexists  ## reformat  and check style with ruff
+	.venv/bin/ruff format ordr3 tests
+	.venv/bin/ruff check ordr3 tests
 
-testall: lint ## run all tests
-	pytest tests -l
+test: lint  ## run tests quickly, stop on first error
+	.venv/bin/pytest tests --stepwise --disable-warnings -m "not functional"
 
-coverage: lint ## functional test suite, check code coverage and open coverage report
-	pytest tests --cov=ordr3 -l -m "fun"
-	coverage html
-	$(BROWSER) htmlcov/index.html
+testfunctional: lint ## run functional tests, stop on first error
+	.venv/bin/pytest tests --stepwise -m "functional"
 
-coverall: lint ## full test suite, check code coverage and open coverage report
-	pytest tests --cov=ordr3 -l
-	coverage html
-	$(BROWSER) htmlcov/index.html
+testall: lint  ## run all tests
+	.venv/bin/pytest tests
 
-tox:  ## run fully isolated tests with tox
-	tox
+tox: venvexists ## run fully isolated tests with tox
+	.venv/bin/tox
 
-install:  ## install updated project.toml with flint
-	flit install --pth-file
+install: venvexists  ## install updated project.toml
+	.venv/bin/pip3 install --upgrade pip wheel
+	.venv/bin/pip3 install -e ".[dev,docs,test]"
 
-devenv: ## setup development environment
+prepareenv:  ## helper to create virtual environment and install basic packages
+	rm -fr .venv/
 	python3 -m venv --prompt ordr3 .venv
-	.venv/bin/pip3 install --upgrade pip
-	.venv/bin/pip3 install "flit>3.2"
-	.venv/bin/flit install --pth-file
+	.venv/bin/pip3 install --upgrade pip wheel
+	.venv/bin/pip3 install -e ".[dev,test]"
+
+devenv: prepareenv  ## setup development environment including precommit hooks
+	.venv/bin/pre-commit install --install-hooks
 
-repo: devenv ## complete project setup with development environment and git repo
+repo: prepareenv ## complete project setup with development environment and git repo
 	git init .
 	git branch -m main
 	git add .

pyproject.toml

@@ -52,45 +52,89 @@ main = "ordr3:main"
 test = [
     "pytest >=4.0.0",
     "pytest-cov",
+    "pytest-icdiff",
     "pytest-mock",
     "pytest-randomly",
     "tox",
     "webtest",
 ]
 dev = [
-    "black",
-    "flake8",
-    "flake8-comprehensions",
-    "flake8-bandit",
-    "isort >= 5.0.0",
+    "ruff",
     "keyring",
     "pre-commit",
 ]
 
-[tool.black]
-line-length = 79
-target-version = ['py37','py38', 'py39']
-include = '\.pyi?$'
-extend-exclude = '''
-# A regex preceded with ^/ will apply only to files and directories
-# in the root of the project.
-^/.git
-^/.tox
-^/.venv
-^/.build
-^/.dist
-'''
-
-[tool.isort]
-line_length=79
-multi_line_output=3
-length_sort="True"
-include_trailing_comma="True"
 
 [tool.pytest.ini_options]
 markers = [
-    "fun: marks tests as functional (deselect with '-m \"not fun\"')",
+    "functional: marks tests as functional (deselect with '-m \"not functional\"')",
 ]
 addopts = [
     "--strict-markers",
+    "--strict-config",
+    "--showlocals",
+    "-ra",
 ]
+
+[tool.ruff]
+# see https://docs.astral.sh/ruff/configuration/
+
+line-length = 80
+indent-width = 4
+
+fix = true
+
+[tool.ruff.lint]
+# Enable Pyflakes (`F`) and a subset of the pycodestyle (`E`)  codes by default.
+# Unlike Flake8, Ruff doesn't enable pycodestyle warnings (`W`) or
+# McCabe complexity (`C901`) by default.
+fixable = ["ALL"]
+select = ["ALL"]
+ignore = [
+    # currently ignored when moving to ruff
+    "ANN",
+    "DTZ",
+    "RUF",
+    "A002",
+    "ARG005",
+    "FBT003",
+    "FLY002",
+    "N802",
+    "N806",
+    "PLR2004",
+    "PT006",
+    "PYI024",
+    "RET504",
+    "SIM117",
+    "TID252",
+    "UP031",
+
+    # ignored for now, should be activated in the future
+    # docstrings
+    "D",
+
+    # don't complain about not annotating self or cls
+    "ANN101",
+    "ANN102",
+
+    # ignored, "ruff format" will handle this
+    "COM812", 
+    "ISC001",
+
+    # ignored, due to Windows / WSL2 setup
+    # flake8-executable
+    "EXE",
+]
+
+[tool.ruff.lint.pydocstyle]
+convention = "pep257"  # Accepts: "google", "numpy", or "pep257".
+
+[tool.ruff.lint.per-file-ignores]
+# see https://github.com/charliermarsh/ruff
+"tests/*" = ["FBT003", "INP001", "PLR2004", "S101", "SLF001", "ANN"]
+"noxfile.py" = ["ANN"]
+
+
+[tool.ruff.format]
+indent-style = "space"
+