Fix remaining pre-existing ty diagnostics in test files

Completes the isinstance/cast narrowing + Optional-field assert pattern
across the last batch of test files. custom_components and tests are
now both fully clean under ruff check, ruff format --check, and ty check.

tests/localthings/test_config_flow.py

@@ -2,7 +2,8 @@
 
 from __future__ import annotations
 
-from typing import Iterable, cast
+from collections.abc import Iterable
+from typing import cast
 from unittest.mock import patch
 
 from homeassistant.core import HomeAssistant

tests/test_air_purifier_capabilities.py

@@ -92,7 +92,9 @@ def test_light_switch_write_contract():
     that the device merges by prefix itself, so no read-modify-write of the
     whole packed /mode/vs/0 options list is needed."""
     desc = next(
-        e for e in air_purifier.MODE.entities if e.key == "display_light" and isinstance(e, SwitchDesc)
+        e
+        for e in air_purifier.MODE.entities
+        if e.key == "display_light" and isinstance(e, SwitchDesc)
     )
     rep = {
         "x.com.samsung.da.options": [
@@ -118,7 +120,9 @@ def test_operating_mode_is_a_read_only_diagnostic():
     guess that it was the fan-speed selector; its real purpose is still
     unconfirmed (see the air_purifier.py module docstring)."""
     operating_mode = next(
-        e for e in air_purifier.MODE.entities if e.key == "operating_mode" and isinstance(e, SensorDesc)
+        e
+        for e in air_purifier.MODE.entities
+        if e.key == "operating_mode" and isinstance(e, SensorDesc)
     )
     rep = {"x.com.samsung.da.options": ["Comode_Off"]}
     assert operating_mode.rep_fn is not None
@@ -154,7 +158,9 @@ def test_airflow_fan_write_contract():
     is a clean, monotonic 0-4 code, so the write is a plain int passthrough
     -- no named-preset table needed (see fan.py's LocalThingsAirflowFan)."""
     fan_desc = next(
-        e for e in air_purifier.AIRFLOW_GENERIC.entities if e.key == "airflow_fan" and isinstance(e, FanDesc)
+        e
+        for e in air_purifier.AIRFLOW_GENERIC.entities
+        if e.key == "airflow_fan" and isinstance(e, FanDesc)
     )
     assert fan_desc.write_fn is not None
     assert fan_desc.write_fn(("speed", 3), {}) == (["airflow", "0"], {"speed": 3})

tests/test_capability.py

@@ -13,8 +13,14 @@ def test_capability_defaults():
 
 def test_capability_is_frozen():
     c = Capability(href="/kidslock/vs/0", entities=())
+    # setattr(), not `c.href = ...` -- `href` is a read-only property to the
+    # type checker (frozen dataclass field), so a literal attribute
+    # assignment doesn't type-check; setattr's signature is untyped enough
+    # to accept it, and it still goes through the same frozen __setattr__
+    # at runtime, so this is still a faithful test of the frozen guarantee.
+    attr_name = "href"
     try:
-        setattr(c, "href", "/other/vs/0")
+        setattr(c, attr_name, "/other/vs/0")
     except Exception:
         return
     raise AssertionError("expected frozen dataclass")

tests/test_dryer_capabilities.py

@@ -75,7 +75,9 @@ def test_course_bound_to_shared_course_vs_0():
     the shipped dryer_cycle_table_03 translations, consistent with
     washer/dishwasher."""
     assert dryer.DRYER_COURSE.href == "/course/vs/0"
-    desc = next(e for e in dryer.DRYER_COURSE.entities if e.key == "cycle" and isinstance(e, SelectDesc))
+    desc = next(
+        e for e in dryer.DRYER_COURSE.entities if e.key == "cycle" and isinstance(e, SelectDesc)
+    )
     assert callable(desc.translation_key)
     table_03 = {"/st/dryercourse/vs/0": {"x.com.samsung.da.st.courseTable": "Table_03"}}
     assert desc.translation_key(table_03) == "dryer_cycle_table_03"

tests/test_laundry_writes.py

@@ -6,7 +6,9 @@ from custom_components.localthings.registry.entities import ButtonDesc, SelectDe
 
 
 def test_start_button_writes_run():
-    btn = next(e for e in OPERATIONAL_STATE.entities if e.key == "start" and isinstance(e, ButtonDesc))
+    btn = next(
+        e for e in OPERATIONAL_STATE.entities if e.key == "start" and isinstance(e, ButtonDesc)
+    )
     assert btn.write_fn is not None
     assert btn.write_fn("Run", {}) == (
         ["operational", "state", "vs", "0"],
@@ -15,7 +17,9 @@ def test_start_button_writes_run():
 
 
 def test_pause_button_writes_pause():
-    btn = next(e for e in OPERATIONAL_STATE.entities if e.key == "pause" and isinstance(e, ButtonDesc))
+    btn = next(
+        e for e in OPERATIONAL_STATE.entities if e.key == "pause" and isinstance(e, ButtonDesc)
+    )
     assert btn.write_fn is not None
     assert btn.write_fn("Pause", {}) == (
         ["operational", "state", "vs", "0"],
@@ -24,7 +28,9 @@ def test_pause_button_writes_pause():
 
 
 def test_stop_button_writes_ready():
-    btn = next(e for e in OPERATIONAL_STATE.entities if e.key == "stop" and isinstance(e, ButtonDesc))
+    btn = next(
+        e for e in OPERATIONAL_STATE.entities if e.key == "stop" and isinstance(e, ButtonDesc)
+    )
     assert btn.write_fn is not None
     assert btn.write_fn("Ready", {}) == (
         ["operational", "state", "vs", "0"],
@@ -33,7 +39,11 @@ def test_stop_button_writes_ready():
 
 
 def test_sound_mode_write_valid():
-    desc = next(e for e in laundry.SOUND_MODE.entities if e.key == "sound_mode" and isinstance(e, SelectDesc))
+    desc = next(
+        e
+        for e in laundry.SOUND_MODE.entities
+        if e.key == "sound_mode" and isinstance(e, SelectDesc)
+    )
     assert desc.write_fn is not None
     assert desc.write_fn("mute", {}) == (
         ["settings", "sound", "mode", "vs", "0"],
@@ -44,7 +54,9 @@ def test_sound_mode_write_valid():
 
 def test_led_brightness_write_valid():
     desc = next(
-        e for e in laundry.DOOR_LED.entities if e.key == "led_brightness" and isinstance(e, SelectDesc)
+        e
+        for e in laundry.DOOR_LED.entities
+        if e.key == "led_brightness" and isinstance(e, SelectDesc)
     )
     assert desc.write_fn is not None
     assert desc.write_fn("Low", {}) == (
@@ -56,7 +68,9 @@ def test_led_brightness_write_valid():
 
 def test_led_night_light_write_valid():
     desc = next(
-        e for e in laundry.DOOR_LED.entities if e.key == "led_night_light" and isinstance(e, SwitchDesc)
+        e
+        for e in laundry.DOOR_LED.entities
+        if e.key == "led_night_light" and isinstance(e, SwitchDesc)
     )
     assert desc.write_fn is not None
     assert desc.write_fn("On", {}) == (