style: say which lint rules this repo keeps, then keep them

`[tool.ruff]` set a line length and a target version and nothing else, so which
rules ran depended on the installed ruff's defaults — fine while nobody ran it,
not fine for a CI job that can turn a push red because a tool changed its mind.

The set is named explicitly (E, F, I, UP, SIM, B, RUF) with three ignores that
are each a real decision rather than a shrug: B008, because FastAPI's whole
dependency idiom is a call in a default argument; E501, because wrapping prose
is a formatter's business; and RUF001, because the reports and the bot speak
Russian and "ambiguous character" is the wrong complaint about a string the
user is meant to read.

The 73 findings that remained are fixed — mostly `datetime.timezone.utc` →
`datetime.UTC`, `typing.Callable` → `collections.abc.Callable`, import order,
and unused `noqa` markers — plus seven by hand: `contextlib.suppress` for two
try/except/pass pairs, unpacking instead of list concatenation, one negated
return.

`ruff format` is deliberately *not* adopted: it would reformat 51 files, and
some of the layout here is hand-set (the comment tables, the DNS wire-format
structs) in ways a formatter flattens.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

backend/app/models.py

@@ -8,7 +8,7 @@ day so a re-send shows the same numbers.
 
 from __future__ import annotations
 
-from datetime import date, datetime, timezone
+from datetime import UTC, date, datetime
 from typing import Any
 
 from sqlalchemy import (
@@ -30,7 +30,7 @@ from app.db import Base
 
 
 def utcnow() -> datetime:
-    return datetime.now(timezone.utc)
+    return datetime.now(UTC)
 
 
 class SettingsRow(Base):
@@ -80,7 +80,7 @@ class PomodoroSession(Base):
     note: Mapped[str | None] = mapped_column(Text)
     abandon_reason: Mapped[str | None] = mapped_column(Text)
 
-    block_events: Mapped[list["BlockEvent"]] = relationship(back_populates="session")
+    block_events: Mapped[list[BlockEvent]] = relationship(back_populates="session")
 
     @property
     def is_work(self) -> bool:

backend/app/services/achievements.py

@@ -8,9 +8,10 @@ the Telegram message at once.
 from __future__ import annotations
 
 import logging
+from collections.abc import Callable
 from dataclasses import dataclass
 from datetime import date
-from typing import Any, Callable
+from typing import Any
 
 Metrics = dict[str, Any]
 Context = dict[str, Any]

backend/app/services/auth_service.py

@@ -17,7 +17,7 @@ import hashlib
 import hmac
 import secrets
 import time
-from datetime import datetime, timedelta, timezone
+from datetime import UTC, datetime, timedelta
 from typing import Any
 
 from sqlalchemy import delete
@@ -84,7 +84,7 @@ def create_session(session: Session, method: str, session_days: int) -> AuthSess
     row = AuthSession(
         token=secrets.token_urlsafe(32),
         method=method,
-        expires_at=datetime.now(timezone.utc) + timedelta(days=session_days),
+        expires_at=datetime.now(UTC) + timedelta(days=session_days),
     )
     session.add(row)
     session.commit()
@@ -93,7 +93,7 @@ def create_session(session: Session, method: str, session_days: int) -> AuthSess
 
 def _aware(dt: datetime) -> datetime:
     """SQLite drops the tzinfo it was stored with; Postgres does not."""
-    return dt if dt.tzinfo else dt.replace(tzinfo=timezone.utc)
+    return dt if dt.tzinfo else dt.replace(tzinfo=UTC)
 
 
 def valid_session(session: Session, token: str | None) -> AuthSession | None:
@@ -102,7 +102,7 @@ def valid_session(session: Session, token: str | None) -> AuthSession | None:
     row = session.get(AuthSession, token)
     if row is None:
         return None
-    if _aware(row.expires_at) < datetime.now(timezone.utc):
+    if _aware(row.expires_at) < datetime.now(UTC):
         session.delete(row)
         session.commit()
         return None
@@ -117,7 +117,7 @@ def delete_session(session: Session, token: str | None) -> None:
 
 
 def _prune_expired(session: Session) -> None:
-    session.execute(delete(AuthSession).where(AuthSession.expires_at < datetime.now(timezone.utc)))
+    session.execute(delete(AuthSession).where(AuthSession.expires_at < datetime.now(UTC)))
 
 
 # --------------------------------------------------------------------------

backend/app/services/settings_service.py

@@ -13,7 +13,8 @@ Three jobs:
 from __future__ import annotations
 
 import threading
-from typing import Any, Callable
+from collections.abc import Callable
+from typing import Any
 
 from sqlalchemy.orm import Session
 

backend/app/services/tasks_service.py

@@ -14,8 +14,9 @@ is recorded as closed today.
 from __future__ import annotations
 
 import logging
+from collections.abc import Iterable
 from datetime import date
-from typing import Any, Iterable
+from typing import Any
 from uuid import uuid4
 
 from sqlalchemy import select

backend/app/services/telegram_bot.py

@@ -10,7 +10,8 @@ from __future__ import annotations
 import logging
 import threading
 import time as time_module
-from typing import Any, Callable
+from collections.abc import Callable
+from typing import Any
 
 import httpx
 

backend/app/sources/base.py

@@ -51,7 +51,7 @@ class SourceResult:
     error: str | None = None
 
     @classmethod
-    def failed(cls, source: str, error: str) -> "SourceResult":
+    def failed(cls, source: str, error: str) -> SourceResult:
         return cls(source=source, items=[], ok=False, error=error)
 
 

backend/app/sources/google_tasks.py

@@ -11,8 +11,9 @@ still things you can spend a pomodoro on.
 
 from __future__ import annotations
 
+from collections.abc import Iterator
 from datetime import date
-from typing import Any, Iterator
+from typing import Any
 
 import httpx
 

backend/app/sources/jira.py

@@ -13,8 +13,9 @@ notices it has left the "open issues" query. One owner per task.
 from __future__ import annotations
 
 import re
+from collections.abc import Iterator
 from datetime import date
-from typing import Any, Iterator
+from typing import Any
 
 import httpx
 

backend/app/sources/registry.py

@@ -8,8 +8,9 @@ empty task list.
 from __future__ import annotations
 
 import logging
+from collections.abc import Callable
 from concurrent.futures import ThreadPoolExecutor
-from typing import Any, Callable
+from typing import Any
 
 from app.settings_schema import AppSettings
 from app.sources.base import SourceError, SourceResult, TodoItem

backend/app/sources/todoist.py

@@ -9,8 +9,9 @@ for people who want the narrower list.
 
 from __future__ import annotations
 
+from collections.abc import Iterator
 from datetime import date
-from typing import Any, Iterator
+from typing import Any
 
 import httpx
 

backend/app/timeutil.py

@@ -7,7 +7,7 @@ for" — here.
 
 from __future__ import annotations
 
-from datetime import date, datetime, time, timedelta, timezone
+from datetime import UTC, date, datetime, time, timedelta
 from zoneinfo import ZoneInfo
 
 
@@ -19,7 +19,7 @@ def tz(name: str) -> ZoneInfo:
 
 
 def now_utc() -> datetime:
-    return datetime.now(timezone.utc)
+    return datetime.now(UTC)
 
 
 def ensure_utc(moment: datetime | None) -> datetime | None:
@@ -31,12 +31,12 @@ def ensure_utc(moment: datetime | None) -> datetime | None:
     """
     if moment is None:
         return None
-    return moment if moment.tzinfo is not None else moment.replace(tzinfo=timezone.utc)
+    return moment if moment.tzinfo is not None else moment.replace(tzinfo=UTC)
 
 
 def to_local(moment: datetime, tz_name: str) -> datetime:
     if moment.tzinfo is None:
-        moment = moment.replace(tzinfo=timezone.utc)
+        moment = moment.replace(tzinfo=UTC)
     return moment.astimezone(tz(tz_name))
 
 
@@ -54,7 +54,7 @@ def day_bounds_utc(day: date, tz_name: str) -> tuple[datetime, datetime]:
     zone = tz(tz_name)
     start = datetime.combine(day, time.min, tzinfo=zone)
     end = start + timedelta(days=1)
-    return start.astimezone(timezone.utc), end.astimezone(timezone.utc)
+    return start.astimezone(UTC), end.astimezone(UTC)
 
 
 def in_window(moment: time, start: time, end: time) -> bool:

backend/pyproject.toml

@@ -35,6 +35,23 @@ packages = ["app"]
 line-length = 90
 target-version = "py312"
 
+# Named rather than left to whatever the installed ruff defaults to, because CI
+# runs this and a silent default change should not turn a push red. `format` is
+# deliberately not enforced: the layout here is hand-set in places (comment
+# tables, the DNS wire-format structs) and a formatter would flatten it.
+[tool.ruff.lint]
+select = ["E", "F", "I", "UP", "SIM", "B", "RUF"]
+ignore = [
+    # FastAPI's whole dependency idiom is a call in a default argument.
+    "B008",
+    # A line-length cap on comments and docstrings is for a formatter to decide.
+    "E501",
+    # The reports and the bot speak Russian as well as English, and the typography
+    # is deliberate (× for counts, – in the laundry source's labels). "Ambiguous
+    # character" is the wrong complaint about a string the user is meant to read.
+    "RUF001",
+]
+
 [tool.pytest.ini_options]
 pythonpath = ["."]
 testpaths = ["tests"]

backend/tests/conftest.py

@@ -61,9 +61,8 @@ def settings(session) -> AppSettings:
 
 @pytest.fixture()
 def client():
-    from fastapi.testclient import TestClient
-
     from app.main import app
+    from fastapi.testclient import TestClient
 
     Base.metadata.drop_all(bind=engine)
     init_db()

backend/tests/test_db_migration.py

@@ -13,10 +13,9 @@ known-dead columns after `create_all`; this pins that behaviour down.
 
 from __future__ import annotations
 
-from sqlalchemy import text
-
 from app.db import SessionLocal, engine, init_db
 from app.models import TaskRecord
+from sqlalchemy import text
 
 
 def _simulate_pre_refactor_database() -> None:

backend/tests/test_pomodoro.py

@@ -3,7 +3,6 @@
 from __future__ import annotations
 
 import pytest
-
 from app.models import PomodoroSession
 from app.services import pomodoro, settings_service
 

backend/tests/test_reports.py

@@ -5,8 +5,8 @@ from __future__ import annotations
 from datetime import timedelta
 
 from app.models import utcnow
-from app.timeutil import local_date
 from app.services import pomodoro, report, settings_service, stats, tasks_service
+from app.timeutil import local_date
 
 
 def _close(session, settings, task) -> None:

desktop/kadence_desktop/__main__.py

@@ -38,7 +38,7 @@ def _remote(verb: str) -> int:
     from PyQt6.QtCore import QCoreApplication
     from PyQt6.QtDBus import QDBusConnection, QDBusInterface
 
-    _app = QCoreApplication(sys.argv)  # noqa: F841 - needed for the D-Bus loop
+    _app = QCoreApplication(sys.argv)
     interface = QDBusInterface(
         "org.kadence.Desktop", "/Timer", "org.kadence.Timer", QDBusConnection.sessionBus()
     )

desktop/kadence_desktop/blocking/hosts.py

@@ -12,6 +12,7 @@ hostname, so the worst a compromised client can do is block a site.
 
 from __future__ import annotations
 
+import contextlib
 import logging
 import os
 import re
@@ -35,7 +36,7 @@ def valid_hostname(name: str) -> bool:
 def current_block() -> list[str]:
     """The hostnames currently inside our managed region of `/etc/hosts`."""
     try:
-        with open(HOSTS_PATH, "r", encoding="utf-8") as handle:
+        with open(HOSTS_PATH, encoding="utf-8") as handle:
             lines = handle.read().splitlines()
     except OSError:
         return []
@@ -124,12 +125,10 @@ class HostsBlocker:
             list_path = handle.name
         os.chmod(list_path, 0o644)  # the helper reads it as root from /tmp
         try:
-            return self._run(runner + ["apply", "--ip", redirect_ip, "--file", list_path])
+            return self._run([*runner, "apply", "--ip", redirect_ip, "--file", list_path])
         finally:
-            try:
+            with contextlib.suppress(OSError):
                 os.unlink(list_path)
-            except OSError:
-                pass
 
     def clear(self) -> bool:
         """Remove the managed region. Safe to call when it is not there."""
@@ -138,7 +137,7 @@ class HostsBlocker:
         runner = self._runner()
         if runner is None:
             return False
-        return self._run(runner + ["clear"])
+        return self._run([*runner, "clear"])
 
     def _run(self, command: list[str]) -> bool:
         try:

desktop/kadence_desktop/blocking/manager.py

@@ -26,8 +26,8 @@ from __future__ import annotations
 
 import logging
 import time
+from collections.abc import Callable
 from types import ModuleType
-from typing import Callable
 
 from kadence_desktop.blocking import processes
 from kadence_desktop.blocking.hosts import HostsBlocker
@@ -262,7 +262,7 @@ class BlockerManager:
                 self._asked[identity] = now
                 self._announce(app, "killed")
 
-    def _announce(self, app: "processes.RunningApp", action: str) -> None:
+    def _announce(self, app: processes.RunningApp, action: str) -> None:
         """Report and notify, at most once per process per cooldown."""
         if not self._claim_report(app.identity):
             return

desktop/kadence_desktop/blocking/processes.py

@@ -23,8 +23,8 @@ from __future__ import annotations
 import logging
 import os
 import signal
-from fnmatch import fnmatch
 from dataclasses import dataclass
+from fnmatch import fnmatch
 from pathlib import Path
 
 log = logging.getLogger(__name__)

desktop/kadence_desktop/blocking/resolver.py

@@ -31,6 +31,7 @@ startup whenever a drop-in is found lying around.
 from __future__ import annotations
 
 import concurrent.futures
+import contextlib
 import fnmatch
 import ipaddress
 import logging
@@ -363,10 +364,8 @@ class StubResolver:
         for sock in (self._udp, self._tcp):
             if sock is None:
                 continue
-            try:
+            with contextlib.suppress(OSError):
                 sock.close()  # the blocking recv/accept raises, ending the loop
-            except OSError:
-                pass
         for thread in self._threads:
             thread.join(timeout=1)
         for pool in (self._handlers, self._forwards):
@@ -407,7 +406,7 @@ class StubResolver:
         while self._running and self._udp is not None:
             try:
                 data, address = self._udp.recvfrom(4096)
-            except socket.timeout:
+            except TimeoutError:
                 continue
             except OSError:
                 break
@@ -431,7 +430,7 @@ class StubResolver:
         while self._running and self._tcp is not None:
             try:
                 connection, _ = self._tcp.accept()
-            except socket.timeout:
+            except TimeoutError:
                 continue
             except OSError:
                 break
@@ -632,7 +631,7 @@ def _parse_nameserver(token: str) -> tuple[str, int] | None:
 def _parse_resolv_conf(path: str) -> list[tuple[str, int]]:
     servers: list[tuple[str, int]] = []
     try:
-        with open(path, "r", encoding="utf-8", errors="replace") as handle:
+        with open(path, encoding="utf-8", errors="replace") as handle:
             lines = handle.read().splitlines()
     except OSError:
         return servers
@@ -704,7 +703,7 @@ class ResolvedRoute:
     def _read_dropin(self) -> tuple[tuple[str, ...], int] | None:
         """What the drop-in currently says, if it is one of ours."""
         try:
-            with open(self.dropin_path, "r", encoding="utf-8") as handle:
+            with open(self.dropin_path, encoding="utf-8") as handle:
                 text = handle.read()
         except OSError:
             return None
@@ -739,7 +738,7 @@ class ResolvedRoute:
         runner = self._runner()
         if runner is None:
             return False
-        command = runner + ["resolved-on", "--port", str(port), "--domains", ",".join(wanted)]
+        command = [*runner, "resolved-on", "--port", str(port), "--domains", ",".join(wanted)]
         if not self._run(command, f"route {len(wanted)} zone(s) through the local stub"):
             return False
         self._applied = (wanted, port)
@@ -753,7 +752,7 @@ class ResolvedRoute:
         runner = self._runner()
         if runner is None:
             return False
-        if not self._run(runner + ["resolved-off"], "stop routing DNS through the local stub"):
+        if not self._run([*runner, "resolved-off"], "stop routing DNS through the local stub"):
             return False
         self._applied = None
         return True

desktop/kadence_desktop/config.py

@@ -107,7 +107,7 @@ class DesktopConfig:
     window: dict = field(default_factory=lambda: {"width": 1100, "height": 760})
 
     @classmethod
-    def load(cls) -> "DesktopConfig":
+    def load(cls) -> DesktopConfig:
         if not CONFIG_PATH.exists():
             config = cls()
             config.save()

desktop/kadence_desktop/integrations/dbus_service.py

@@ -19,7 +19,7 @@ every documented command then hits.
 from __future__ import annotations
 
 import logging
-from typing import Callable
+from collections.abc import Callable
 
 from PyQt6.QtCore import QObject, pyqtClassInfo, pyqtSlot
 from PyQt6.QtDBus import QDBusAbstractAdaptor, QDBusConnection
@@ -92,60 +92,60 @@ class TimerAdaptor(QDBusAbstractAdaptor):
 
     # D-Bus methods are PascalCase by convention.
     @pyqtSlot(result=str)
-    def StartWork(self) -> str:  # noqa: N802
+    def StartWork(self) -> str:
         """Start a focus interval."""
         return self._service.run("start_work")
 
     @pyqtSlot(result=str)
-    def StartBreak(self) -> str:  # noqa: N802
+    def StartBreak(self) -> str:
         return self._service.run("start_break")
 
     @pyqtSlot(result=str)
-    def Toggle(self) -> str:  # noqa: N802
+    def Toggle(self) -> str:
         """Start if idle, pause if running, resume if paused — one hotkey."""
         return self._service.run("toggle")
 
     @pyqtSlot(result=str)
-    def Pause(self) -> str:  # noqa: N802
+    def Pause(self) -> str:
         return self._service.run("pause")
 
     @pyqtSlot(result=str)
-    def Resume(self) -> str:  # noqa: N802
+    def Resume(self) -> str:
         return self._service.run("resume")
 
     @pyqtSlot(result=str)
-    def Complete(self) -> str:  # noqa: N802
+    def Complete(self) -> str:
         return self._service.run("complete")
 
     @pyqtSlot(result=str)
-    def Stop(self) -> str:  # noqa: N802
+    def Stop(self) -> str:
         return self._service.run("stop")
 
     @pyqtSlot(result=str)
-    def Extend(self) -> str:  # noqa: N802
+    def Extend(self) -> str:
         return self._service.run("extend")
 
     @pyqtSlot(result=str)
-    def Interrupt(self) -> str:  # noqa: N802
+    def Interrupt(self) -> str:
         """Count a distraction without stopping the clock."""
         return self._service.run("interrupt")
 
     @pyqtSlot(result=str)
-    def Status(self) -> str:  # noqa: N802
+    def Status(self) -> str:
         """One line: what is running and how much is left."""
         return self._service.run("status")
 
     @pyqtSlot(result=str)
-    def SendReport(self) -> str:  # noqa: N802
+    def SendReport(self) -> str:
         return self._service.run("send_report")
 
     @pyqtSlot(result=str)
-    def ToggleMini(self) -> str:  # noqa: N802
+    def ToggleMini(self) -> str:
         """Show or hide the floating mini timer."""
         return self._service.run("toggle_mini")
 
     @pyqtSlot(result=str)
-    def Raise(self) -> str:  # noqa: N802
+    def Raise(self) -> str:
         """Show the main window (used by a second instance)."""
         return self._service.run("raise_window")
 

desktop/kadence_desktop/integrations/keep_above.py

@@ -155,9 +155,7 @@ def up_to_date(position: tuple[int, int] | None = None) -> bool:
         if any(parser.get(section, key, fallback=None) != value for key, value in wanted.items()):
             return False
         # A position left over from a previous corner must not linger.
-        if position is None and parser.has_option(section, "position"):
-            return False
-        return True
+        return not (position is None and parser.has_option(section, "position"))
     except (configparser.Error, OSError):
         return False
 

desktop/kadence_desktop/integrations/notifications.py

@@ -10,7 +10,7 @@ so a running timer never stacks up a column of toasts.
 from __future__ import annotations
 
 import logging
-from typing import Callable
+from collections.abc import Callable
 
 from PyQt6.QtCore import QMetaType, QObject, QVariant, pyqtSlot
 from PyQt6.QtDBus import QDBusArgument, QDBusConnection, QDBusInterface, QDBusMessage

desktop/tests/test_placement.py

@@ -7,7 +7,6 @@ that silently puts a window half off the screen on somebody else's monitor.
 from __future__ import annotations
 
 import pytest
-
 from kadence_desktop.integrations.placement import CORNER_LABELS, CORNERS, Rect, point_for
 
 SCREEN = Rect(0, 0, 1536, 960)

desktop/tests/test_resolver.py

@@ -18,7 +18,6 @@ import threading
 from pathlib import Path
 
 import pytest
-
 from kadence_desktop.blocking.resolver import (
     ResolvedRoute,
     StubResolver,