use ruff linter and formatter

.flake8

@@ -1,25 +0,0 @@
-[flake8]
-extend-select =
-    # bugbear
-    B
-    # bugbear opinions
-    B9
-    # implicit str concat
-    ISC
-extend-ignore =
-    # slice notation whitespace, invalid
-    E203
-    # line length, handled by bugbear B950
-    E501
-    # bare except, handled by bugbear B001
-    E722
-    # zip with strict=, requires python >= 3.10
-    B905
-    # string formatting opinion, B028 renamed to B907
-    B028
-    B907
-# up to 88 allowed by bugbear B950
-max-line-length = 80
-per-file-ignores =
-    # __init__ exports names
-    src/flask/__init__.py: F401

.gitignore

@@ -1,25 +1,10 @@
-.DS_Store
-.env
-.flaskenv
-*.pyc
-*.pyo
-env/
-venv/
-.venv/
-env*
-dist/
-build/
-*.egg
-*.egg-info/
-.tox/
-.cache/
-.pytest_cache/
 .idea/
-docs/_build/
+.vscode/
-.vscode
+__pycache__/
-
+.tox/
-# Coverage reports
-htmlcov/
 .coverage
 .coverage.*
-*,cover
+htmlcov/
+docs/_build/
+dist/
+venv/

.pre-commit-config.yaml

@@ -1,37 +1,16 @@
 ci:
-  autoupdate_branch: "2.3.x"
   autoupdate_schedule: monthly
 repos:
-  - repo: https://github.com/asottile/pyupgrade
+  - repo: https://github.com/astral-sh/ruff-pre-commit
-    rev: v3.10.1
+    rev: v0.1.3
     hooks:
-      - id: pyupgrade
+      - id: ruff
-        args: ["--py38-plus"]
+      - id: ruff-format
-  - repo: https://github.com/asottile/reorder-python-imports
-    rev: v3.10.0
-    hooks:
-      - id: reorder-python-imports
-        name: Reorder Python imports (src, tests)
-        files: "^(?!examples/)"
-        args: ["--application-directories", "src"]
-  - repo: https://github.com/psf/black
-    rev: 23.7.0
-    hooks:
-      - id: black
-  - repo: https://github.com/PyCQA/flake8
-    rev: 6.1.0
-    hooks:
-      - id: flake8
-        additional_dependencies:
-          - flake8-bugbear
-          - flake8-implicit-str-concat
-  - repo: https://github.com/peterdemin/pip-compile-multi
-    rev: v2.6.3
-    hooks:
-      - id: pip-compile-multi-verify
   - repo: https://github.com/pre-commit/pre-commit-hooks
     rev: v4.4.0
     hooks:
+      - id: check-merge-conflict
+      - id: debug-statements
       - id: fix-byte-order-marker
       - id: trailing-whitespace
       - id: end-of-file-fixer

examples/celery/pyproject.toml

@@ -12,3 +12,6 @@ build-backend = "flit_core.buildapi"
 
 [tool.flit.module]
 name = "task_app"
+
+[tool.ruff]
+src = ["src"]

examples/javascript/js_example/views.py

@@ -2,7 +2,7 @@ from flask import jsonify
 from flask import render_template
 from flask import request
 
-from js_example import app
+from . import app
 
 
 @app.route("/", defaults={"js": "fetch"})

examples/javascript/pyproject.toml

@@ -27,3 +27,6 @@ filterwarnings = ["error"]
 [tool.coverage.run]
 branch = true
 source = ["js_example", "tests"]
+
+[tool.ruff]
+src = ["src"]

examples/tutorial/flaskr/__init__.py

@@ -31,12 +31,13 @@ def create_app(test_config=None):
         return "Hello, World!"
 
     # register the database commands
-    from flaskr import db
+    from . import db
 
     db.init_app(app)
 
     # apply the blueprints to the app
-    from flaskr import auth, blog
+    from . import auth
+    from . import blog
 
     app.register_blueprint(auth.bp)
     app.register_blueprint(blog.bp)

examples/tutorial/flaskr/auth.py

@@ -11,7 +11,7 @@ from flask import url_for
 from werkzeug.security import check_password_hash
 from werkzeug.security import generate_password_hash
 
-from flaskr.db import get_db
+from .db import get_db
 
 bp = Blueprint("auth", __name__, url_prefix="/auth")
 

examples/tutorial/flaskr/blog.py

@@ -7,8 +7,8 @@ from flask import request
 from flask import url_for
 from werkzeug.exceptions import abort
 
-from flaskr.auth import login_required
+from .auth import login_required
-from flaskr.db import get_db
+from .db import get_db
 
 bp = Blueprint("blog", __name__)
 

examples/tutorial/pyproject.toml

@@ -34,3 +34,6 @@ filterwarnings = ["error"]
 [tool.coverage.run]
 branch = true
 source = ["flaskr", "tests"]
+
+[tool.ruff]
+src = ["src"]

pyproject.toml

@@ -106,3 +106,24 @@ module = [
     "importlib_metadata",
 ]
 ignore_missing_imports = true
+
+[tool.ruff]
+src = ["src"]
+fix = true
+show-fixes = true
+show-source = true
+
+[tool.ruff.lint]
+select = [
+    "B",  # flake8-bugbear
+    "E",  # pycodestyle error
+    "F",  # pyflakes
+    "I",  # isort
+    "UP",  # pyupgrade
+    "W",  # pycodestyle warning
+]
+ignore-init-module-imports = true
+
+[tool.ruff.lint.isort]
+force-single-line = true
+order-by-type = false

src/flask/app.py

@@ -1183,7 +1183,8 @@ class Flask(App):
                 # class to the correct type
                 try:
                     rv = self.response_class.force_type(
-                        rv, request.environ  # type: ignore[arg-type]
+                        rv,  # type: ignore[arg-type]
+                        request.environ,
                     )
                 except TypeError as e:
                     raise TypeError(
@@ -1272,7 +1273,8 @@ class Flask(App):
         return response
 
     def do_teardown_request(
-        self, exc: BaseException | None = _sentinel  # type: ignore
+        self,
+        exc: BaseException | None = _sentinel,  # type: ignore[assignment]
     ) -> None:
         """Called after the request is dispatched and the response is
         returned, right before the request context is popped.
@@ -1305,7 +1307,8 @@ class Flask(App):
         request_tearing_down.send(self, _async_wrapper=self.ensure_sync, exc=exc)
 
     def do_teardown_appcontext(
-        self, exc: BaseException | None = _sentinel  # type: ignore
+        self,
+        exc: BaseException | None = _sentinel,  # type: ignore[assignment]
     ) -> None:
         """Called right before the application context is popped.
 

src/flask/helpers.py

@@ -21,6 +21,7 @@ from .signals import message_flashed
 
 if t.TYPE_CHECKING:  # pragma: no cover
     from werkzeug.wrappers import Response as BaseResponse
+
     from .wrappers import Response
 
 
@@ -48,9 +49,7 @@ def get_load_dotenv(default: bool = True) -> bool:
 
 
 def stream_with_context(
-    generator_or_function: (
+    generator_or_function: t.Iterator[t.AnyStr] | t.Callable[..., t.Iterator[t.AnyStr]]
-        t.Iterator[t.AnyStr] | t.Callable[..., t.Iterator[t.AnyStr]]
-    )
 ) -> t.Iterator[t.AnyStr]:
     """Request contexts disappear when the response is started on the server.
     This is done for efficiency reasons and to make it less likely to encounter

src/flask/json/provider.py

@@ -134,9 +134,7 @@ class DefaultJSONProvider(JSONProvider):
         method) will call the ``__html__`` method to get a string.
     """
 
-    default: t.Callable[[t.Any], t.Any] = staticmethod(
+    default: t.Callable[[t.Any], t.Any] = staticmethod(_default)  # type: ignore[assignment]
-        _default
-    )  # type: ignore[assignment]
     """Apply this function to any object that :meth:`json.dumps` does
     not know how to serialize. It should return a valid JSON type or
     raise a ``TypeError``.

src/flask/sansio/app.py

@@ -35,9 +35,10 @@ from .scaffold import setupmethod
 
 if t.TYPE_CHECKING:  # pragma: no cover
     from werkzeug.wrappers import Response as BaseResponse
-    from .blueprints import Blueprint
+
     from ..testing import FlaskClient
     from ..testing import FlaskCliRunner
+    from .blueprints import Blueprint
 
 T_shell_context_processor = t.TypeVar(
     "T_shell_context_processor", bound=ft.ShellContextProcessorCallable
@@ -905,7 +906,9 @@ class App(Scaffold):
             Moved from ``flask.redirect``, which calls this method.
         """
         return _wz_redirect(
-            location, code=code, Response=self.response_class  # type: ignore[arg-type]
+            location,
+            code=code,
+            Response=self.response_class,  # type: ignore[arg-type]
         )
 
     def inject_url_defaults(self, endpoint: str, values: dict) -> None:

src/flask/sessions.py

@@ -14,7 +14,8 @@ from .json.tag import TaggedJSONSerializer
 
 if t.TYPE_CHECKING:  # pragma: no cover
     from .app import Flask
-    from .wrappers import Request, Response
+    from .wrappers import Request
+    from .wrappers import Response
 
 
 class SessionMixin(MutableMapping):

src/flask/views.py

@@ -6,7 +6,6 @@ from . import typing as ft
 from .globals import current_app
 from .globals import request
 
-
 http_method_funcs = frozenset(
     ["get", "post", "head", "options", "delete", "put", "trace", "patch"]
 )

tests/test_appctx.py

@@ -196,17 +196,14 @@ def test_clean_pop(app):
 
     @app.teardown_request
     def teardown_req(error=None):
-        1 / 0
+        raise ZeroDivisionError
 
     @app.teardown_appcontext
     def teardown_app(error=None):
         called.append("TEARDOWN")
 
-    try:
+    with app.app_context():
-        with app.test_request_context():
+        called.append(flask.current_app.name)
-            called.append(flask.current_app.name)
-    except ZeroDivisionError:
-        pass
 
     assert called == ["flask_test", "TEARDOWN"]
     assert not flask.current_app

tests/test_apps/subdomaintestmodule/__init__.py

@@ -1,4 +1,3 @@
 from flask import Module
 
-
 mod = Module(__name__, "foo", subdomain="foo")

tests/test_basic.py

@@ -19,7 +19,6 @@ from werkzeug.routing import RequestRedirect
 
 import flask
 
-
 require_cpython_gc = pytest.mark.skipif(
     python_implementation() != "CPython",
     reason="Requires CPython GC behavior",
@@ -190,7 +189,8 @@ def test_url_mapping(app, client):
 
 
 def test_werkzeug_routing(app, client):
-    from werkzeug.routing import Submount, Rule
+    from werkzeug.routing import Rule
+    from werkzeug.routing import Submount
 
     app.url_map.add(
         Submount("/foo", [Rule("/bar", endpoint="bar"), Rule("/", endpoint="index")])
@@ -210,7 +210,8 @@ def test_werkzeug_routing(app, client):
 
 
 def test_endpoint_decorator(app, client):
-    from werkzeug.routing import Submount, Rule
+    from werkzeug.routing import Rule
+    from werkzeug.routing import Submount
 
     app.url_map.add(
         Submount("/foo", [Rule("/bar", endpoint="bar"), Rule("/", endpoint="index")])
@@ -431,9 +432,9 @@ def test_session_special_types(app, client):
         client.get("/")
         s = flask.session
         assert s["t"] == (1, 2, 3)
-        assert type(s["b"]) is bytes
+        assert type(s["b"]) is bytes  # noqa: E721
         assert s["b"] == b"\xff"
-        assert type(s["m"]) is Markup
+        assert type(s["m"]) is Markup  # noqa: E721
         assert s["m"] == Markup("<html>")
         assert s["u"] == the_uuid
         assert s["d"] == now
@@ -784,7 +785,7 @@ def test_teardown_request_handler_error(app, client):
 
     @app.route("/")
     def fails():
-        1 // 0
+        raise ZeroDivisionError
 
     rv = client.get("/")
     assert rv.status_code == 500
@@ -851,7 +852,7 @@ def test_error_handling(app, client):
 
     @app.route("/error")
     def error():
-        1 // 0
+        raise ZeroDivisionError
 
     @app.route("/forbidden")
     def error2():
@@ -877,7 +878,7 @@ def test_error_handling_processing(app, client):
 
     @app.route("/")
     def broken_func():
-        1 // 0
+        raise ZeroDivisionError
 
     @app.after_request
     def after_request(resp):
@@ -1047,12 +1048,13 @@ def test_error_handler_after_processor_error(app, client):
     @app.before_request
     def before_request():
         if _trigger == "before":
-            1 // 0
+            raise ZeroDivisionError
 
     @app.after_request
     def after_request(response):
         if _trigger == "after":
-            1 // 0
+            raise ZeroDivisionError
+
         return response
 
     @app.route("/")
@@ -1507,7 +1509,7 @@ def test_exception_propagation(app, client, key):
 
     @app.route("/")
     def index():
-        1 // 0
+        raise ZeroDivisionError
 
     if key is not None:
         app.config[key] = True

tests/test_blueprints.py

@@ -634,10 +634,11 @@ def test_add_template_test_with_name_and_template(app, client):
 def test_context_processing(app, client):
     answer_bp = flask.Blueprint("answer_bp", __name__)
 
-    template_string = lambda: flask.render_template_string(  # noqa: E731
+    def template_string():
-        "{% if notanswer %}{{ notanswer }} is not the answer. {% endif %}"
+        return flask.render_template_string(
-        "{% if answer %}{{ answer }} is the answer.{% endif %}"
+            "{% if notanswer %}{{ notanswer }} is not the answer. {% endif %}"
-    )
+            "{% if answer %}{{ answer }} is the answer.{% endif %}"
+        )
 
     # App global context processor
     @answer_bp.app_context_processor

tests/test_signals.py

@@ -98,7 +98,7 @@ def test_request_exception_signal():
 
     @app.route("/")
     def index():
-        1 // 0
+        raise ZeroDivisionError
 
     def record(sender, exception):
         recorded.append(exception)
@@ -169,7 +169,7 @@ def test_appcontext_tearing_down_signal(app, client):
 
     @app.route("/")
     def index():
-        1 // 0
+        raise ZeroDivisionError
 
     flask.appcontext_tearing_down.connect(record_teardown, app)
     try:

tests/test_testing.py

@@ -219,7 +219,7 @@ def test_test_client_context_binding(app, client):
 
     @app.route("/other")
     def other():
-        1 // 0
+        raise ZeroDivisionError
 
     with client:
         resp = client.get("/")
@@ -227,18 +227,15 @@ def test_test_client_context_binding(app, client):
         assert resp.data == b"Hello World!"
         assert resp.status_code == 200
 
+    with client:
         resp = client.get("/other")
         assert not hasattr(flask.g, "value")
         assert b"Internal Server Error" in resp.data
         assert resp.status_code == 500
         flask.g.value = 23
 
-    try:
+    with pytest.raises(RuntimeError):
-        flask.g.value
+        flask.g.value  # noqa: B018
-    except (AttributeError, RuntimeError):
-        pass
-    else:
-        raise AssertionError("some kind of exception expected")
 
 
 def test_reuse_client(client):

tests/test_views.py

@@ -41,10 +41,10 @@ def test_method_based_view(app):
 def test_view_patching(app):
     class Index(flask.views.MethodView):
         def get(self):
-            1 // 0
+            raise ZeroDivisionError
 
         def post(self):
-            1 // 0
+            raise ZeroDivisionError
 
     class Other(Index):
         def get(self):

tests/typing/typing_app_decorators.py

@@ -1,7 +1,5 @@
 from __future__ import annotations
 
-import typing as t
-
 from flask import Flask
 from flask import Response
 
@@ -29,10 +27,10 @@ async def before_async() -> None:
 
 
 @app.teardown_appcontext
-def teardown_sync(exc: t.Optional[BaseException]) -> None:
+def teardown_sync(exc: BaseException | None) -> None:
     ...
 
 
 @app.teardown_appcontext
-async def teardown_async(exc: t.Optional[BaseException]) -> None:
+async def teardown_async(exc: BaseException | None) -> None:
     ...

tests/typing/typing_route.py

@@ -29,12 +29,12 @@ def hello_json() -> Response:
 
 
 @app.route("/json/dict")
-def hello_json_dict() -> t.Dict[str, t.Any]:
+def hello_json_dict() -> dict[str, t.Any]:
     return {"response": "Hello, World!"}
 
 
 @app.route("/json/dict")
-def hello_json_list() -> t.List[t.Any]:
+def hello_json_list() -> list[t.Any]:
     return [{"message": "Hello"}, {"message": "World"}]