style: fix lint errors surfaced by ruff v0.16.0 (#72)

Ruff 0.16.0 enables new rules that flag existing code. Apply the safe
autofixes and resolve the remaining findings:

- RUF046: drop redundant int() around math.ceil()/round() (already int)
- PIE810: merge repeated startswith() calls into a single tuple call
- G201/TRY401: use logger.exception() instead of logger.error(exc_info=True)
  and drop the redundant exception object from the message
- SIM117: combine nested with statements
- plus ruff's safe autofixes (import order, max(), unused noqa, redundant
  parens)


Claude-Session: https://claude.ai/code/session_01PjbdedU3mPd5uYrTibuFpJ

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: bakerkj

custom_components/cpu_capacity/__init__.py

@@ -3,8 +3,8 @@
 
 from __future__ import annotations
 
-from dataclasses import dataclass
 import logging
+from dataclasses import dataclass
 
 from homeassistant.config_entries import ConfigEntry
 from homeassistant.core import HomeAssistant

custom_components/cpu_capacity/coordinator.py

@@ -293,7 +293,7 @@ def __init__(
         }
 
         self._window_sizes: dict[str, int] = {
-            label: max(1, int(math.ceil(seconds / self._sample_interval_seconds)))
+            label: max(1, math.ceil(seconds / self._sample_interval_seconds))
             for label, seconds in WINDOW_SECONDS.items()
         }
 
@@ -379,10 +379,8 @@ async def _async_take_sample(self) -> None:
                 await self.hass.async_add_executor_job(self._take_sample_sync)
             except (OSError, ValueError) as err:
                 self.logger.warning("CPU sampling failed: %s", err)
-            except Exception as err:  # noqa: BLE001
-                self.logger.error(
-                    "Unexpected error during CPU sampling: %s", err, exc_info=True
-                )
+            except Exception:
+                self.logger.exception("Unexpected error during CPU sampling")
 
     async def async_get_snapshot(self) -> CoordinatorSnapshot:
         async with self._lock:
@@ -433,8 +431,7 @@ def _take_sample_sync(self) -> None:
             dt = cur_total - prev_total
             di = cur_idle - prev_idle
             busy = dt - di
-            if busy < 0:
-                busy = 0
+            busy = max(busy, 0)
 
             load_pct = (float(busy) * 100.0 / float(dt)) if dt > 0 else 0.0
             mhz = current_mhz_by_cpu.get(cpu, 0.0)
@@ -537,7 +534,7 @@ async def _async_update_data(self) -> CoordinatorSnapshot:
         age = time.time() - snapshot["last_sample_epoch"]
         if age > stale_timeout:
             raise UpdateFailed(
-                (f"CPU sample data is stale ({age:.1f}s > {stale_timeout:.1f}s)")
+                f"CPU sample data is stale ({age:.1f}s > {stale_timeout:.1f}s)"
             )
 
         return snapshot

custom_components/cpu_capacity/sensor.py

@@ -3,8 +3,8 @@
 
 from __future__ import annotations
 
-from dataclasses import dataclass
 import re
+from dataclasses import dataclass
 from typing import Any
 
 from homeassistant.components.sensor import (
@@ -165,8 +165,8 @@ def _round_summary_value(key: str, value: Any) -> Any:
 
     number = float(value)
     if key == "max_mhz" or key.startswith("mhz_"):
-        return int(round(number))
-    if key.startswith("load_pct_") or key.startswith("capacity_adjusted_load_pct_"):
+        return round(number)
+    if key.startswith(("load_pct_", "capacity_adjusted_load_pct_")):
         return round(number, 4)
     return value
 
@@ -193,9 +193,7 @@ def _round_native_value(metric_key: str, value: Any) -> Any:
     number = float(value)
     if metric_key == "max_mhz" or metric_key.startswith("mhz_"):
         return int(round(number / _MHZ_NATIVE_STEP) * _MHZ_NATIVE_STEP)
-    if metric_key.startswith("load_pct_") or metric_key.startswith(
-        "capacity_adjusted_load_pct_"
-    ):
+    if metric_key.startswith(("load_pct_", "capacity_adjusted_load_pct_")):
         return round(number, 1)
     return value
 

tests/test_coordinator.py

@@ -16,7 +16,6 @@
     _safe_read_text,
 )
 
-
 # ---------------------------------------------------------------------------
 # RollingWindow
 # ---------------------------------------------------------------------------
@@ -155,9 +154,11 @@ def test_total_is_sum_of_all_fields(self) -> None:
 
     def test_raises_if_no_cpu_entries(self) -> None:
         empty = "no cpu lines here\n"
-        with patch("builtins.open", return_value=StringIO(empty)):
-            with pytest.raises(RuntimeError, match="No per-CPU entries found"):
-                _read_proc_stat_totals()
+        with (
+            patch("builtins.open", return_value=StringIO(empty)),
+            pytest.raises(RuntimeError, match="No per-CPU entries found"),
+        ):
+            _read_proc_stat_totals()
 
 
 # ---------------------------------------------------------------------------
@@ -194,11 +195,13 @@ def test_returns_empty_dict_on_oserror(self) -> None:
 
     def test_logs_debug_on_error(self) -> None:
         logger = MagicMock()
-        with patch("builtins.open", side_effect=OSError("boom")):
-            with patch(
+        with (
+            patch("builtins.open", side_effect=OSError("boom")),
+            patch(
                 "custom_components.cpu_capacity.coordinator.logging.getLogger",
                 return_value=logger,
-            ):
-                _parse_proc_cpuinfo_mhz_map()
+            ),
+        ):
+            _parse_proc_cpuinfo_mhz_map()
         logger.debug.assert_called_once()
         assert "MHz fallback" in logger.debug.call_args[0][0]

tests/test_publish_intervals.py

@@ -10,9 +10,9 @@
     _publish_error,
 )
 from custom_components.cpu_capacity.const import (
-    CONF_PUBLISH_INTERVAL_15M_SECONDS,
     CONF_PUBLISH_INTERVAL_1M_SECONDS,
     CONF_PUBLISH_INTERVAL_5M_SECONDS,
+    CONF_PUBLISH_INTERVAL_15M_SECONDS,
     CONF_PUBLISH_INTERVAL_SECONDS,
     CONF_SAMPLE_INTERVAL_SECONDS,
     DEFAULT_PUBLISH_INTERVAL_SECONDS,
@@ -21,7 +21,6 @@
 )
 from custom_components.cpu_capacity.sensor import _window_for_metric
 
-
 # ---------------------------------------------------------------------------
 # resolve_publish_interval
 # ---------------------------------------------------------------------------