Use Ruff for code linting and checking

Ruff does the same as flake8(+plugins)+pyupgrade+isort, but much faster
and can also automatically fix many of these quirks too.

It ignores all files that are ignored by git, so all the exclude rules
are not necessary.

I have left isort-related rules out for now since they results in some
changes which might add noise at this point.

5 files changed, 13 insertions, 24 deletions

diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 7cdee0b2..84dae0b4 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -13,19 +13,6 @@ repos:
     hooks:
       - id: isort
         name: isort (python)
-  - repo: https://github.com/PyCQA/flake8
-    rev: 6.0.0
-    hooks:
-      - id: flake8
-        additional_dependencies:
-          - flake8-comprehensions
-          - flake8-bugbear
-        exclude: doc/source/conf.py
-  - repo: https://github.com/asottile/pyupgrade
-    rev: v3.3.1
-    hooks:
-    -   id: pyupgrade
-        args: [--py36-plus]
   - repo: https://github.com/pre-commit/mirrors-mypy
     rev: v1.0.0
     hooks:
@@ -37,3 +24,8 @@ repos:
           - types-pytz
           - types-setuptools
           - types-python-dateutil
+  - repo: https://github.com/charliermarsh/ruff-pre-commit
+    rev: 'v0.0.244'
+    hooks:
+      - id: ruff
+        args: ["--fix"]
diff --git a/doc/source/hacking.rst b/doc/source/hacking.rst
index 9df986aa..33bf0df5 100644
--- a/doc/source/hacking.rst
+++ b/doc/source/hacking.rst
@@ -127,7 +127,7 @@ Code Style
 khal's source code should adhere to the rules laid out in :pep:`008`, except
 for allowing line lengths of up to 100 characters if it improves
 overall legibility (use your judgement).  This can be checked by installing and
-running flake8_ (run with :command:`flake8` from khal's source directory), which
+running ruff_ (run with :command:`ruff` from khal's source directory), which
 will also be run with tox and GitHub Actions, see section above.
 
 We try to document the parameters functions and methods accept, including their
@@ -148,7 +148,7 @@ identifiers, e.g., in dictionary keys::
 .. _tox: https://tox.readthedocs.org/
 .. _pytest: http://pytest.org/
 .. _pytest-cov: https://pypi.python.org/pypi/pytest-cov
-.. _flake8: http://flake8.pycqa.org/
+.. _ruff: https://github.com/charliermarsh/ruff
 .. _sphinx: http://www.sphinx-doc.org
 .. _restructuredtext: http://www.sphinx-doc.org/en/1.5.1/rest.html
 .. _ipdb: https://pypi.python.org/pypi/ipdb
diff --git a/khal/khalendar/event.py b/khal/khalendar/event.py
index 8f3a88fc..a653f94f 100644
--- a/khal/khalendar/event.py
+++ b/khal/khalendar/event.py
@@ -209,7 +209,7 @@ class Event:
 
         beware, this methods performs some open heart surgery
         """
-        if type(start) != type(end):  # flake8: noqa
+        if type(start) != type(end):
             raise ValueError('DTSTART and DTEND should be of the same type (datetime or date)')
         self.__class__ = self._get_type_from_date(start)
 
diff --git a/pyproject.toml b/pyproject.toml
new file mode 100644
index 00000000..537cc6ed
--- /dev/null
+++ b/pyproject.toml
@@ -0,0 +1,5 @@
+[tool.ruff]
+select = ["E", "F", "W", "B0", "UP", "C4"]
+ignore = ["B008"]
+line-length = 100
+target-version = "py38"
diff --git a/tox.ini b/tox.ini
index 8b32e21d..80d30619 100644
--- a/tox.ini
+++ b/tox.ini
@@ -42,14 +42,6 @@ commands =
   make -C doc html
   make -C doc man
 
-[flake8]
-max-line-length = 100
-ignore = E252,W504,E121,B008
-exclude = .tox,examples,doc
-extend-ignore =
-  # Line jump before binary operator.
-  W503,
-
 [mypy]
 # Silence warnings given by using untyped libraries:
 ignore_missing_imports = True