Fix restoring isy994 brightness with no previous state

CODEOWNERS

@@ -196,6 +196,7 @@ homeassistant/components/ipp/* @ctalkington
 homeassistant/components/iqvia/* @bachya
 homeassistant/components/irish_rail_transport/* @ttroy50
 homeassistant/components/islamic_prayer_times/* @engrbm87
+homeassistant/components/isy994/* @bdraco
 homeassistant/components/izone/* @Swamp-Ig
 homeassistant/components/jewish_calendar/* @tsvi
 homeassistant/components/juicenet/* @jesserockz

homeassistant/components/isy994/light.py

@@ -3,12 +3,15 @@
 from typing import Callable
 
 from homeassistant.components.light import DOMAIN, SUPPORT_BRIGHTNESS, LightEntity
+from homeassistant.helpers.restore_state import RestoreEntity
 from homeassistant.helpers.typing import ConfigType
 
 from . import ISY994_NODES, ISYDevice
 
 _LOGGER = logging.getLogger(__name__)
 
+ATTR_LAST_BRIGHTNESS = "last_brightness"
+
 
 def setup_platform(
     hass, config: ConfigType, add_entities: Callable[[list], None], discovery_info=None
@@ -21,7 +24,7 @@ def setup_platform(
     add_entities(devices)
 
 
-class ISYLightDevice(ISYDevice, LightEntity):
+class ISYLightDevice(ISYDevice, LightEntity, RestoreEntity):
     """Representation of an ISY994 light device."""
 
     def __init__(self, node) -> None:
@@ -56,7 +59,7 @@ def on_update(self, event: object) -> None:
     # pylint: disable=arguments-differ
     def turn_on(self, brightness=None, **kwargs) -> None:
         """Send the turn on command to the ISY994 light device."""
-        if brightness is None and self._last_brightness is not None:
+        if brightness is None and self._last_brightness:
             brightness = self._last_brightness
         if not self._node.on(val=brightness):
             _LOGGER.debug("Unable to turn on light")
@@ -65,3 +68,22 @@ def turn_on(self, brightness=None, **kwargs) -> None:
     def supported_features(self):
         """Flag supported features."""
         return SUPPORT_BRIGHTNESS
+
+    @property
+    def device_state_attributes(self):
+        """Return the light attributes."""
+        return {ATTR_LAST_BRIGHTNESS: self._last_brightness}
+
+    async def async_added_to_hass(self) -> None:
+        """Restore last_brightness on restart."""
+        await super().async_added_to_hass()
+
+        last_state = await self.async_get_last_state()
+        if not last_state:
+            return
+
+        if (
+            ATTR_LAST_BRIGHTNESS in last_state.attributes
+            and last_state.attributes[ATTR_LAST_BRIGHTNESS]
+        ):
+            self._last_brightness = last_state.attributes[ATTR_LAST_BRIGHTNESS]

homeassistant/components/isy994/manifest.json

@@ -3,5 +3,5 @@
   "name": "Universal Devices ISY994",
   "documentation": "https://www.home-assistant.io/integrations/isy994",
   "requirements": ["PyISY==1.1.2"],
-  "codeowners": []
+  "codeowners": ["@bdraco"]
 }