From f985fafbf5abcd121d256c619efc4df320073cfc Mon Sep 17 00:00:00 2001
From: Stefan Agner <stefan@agner.ch>
Date: Fri, 28 Aug 2026 17:47:15 +0200
Subject: [PATCH] Don't attach a device to iotawatt entities without a unique
 ID (#180505)

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>
---
 homeassistant/components/iotawatt/sensor.py | 18 ++++-------
 tests/components/iotawatt/test_sensor.py    | 36 ++++++++++++++++++++-
 2 files changed, 41 insertions(+), 13 deletions(-)

diff --git a/homeassistant/components/iotawatt/sensor.py b/homeassistant/components/iotawatt/sensor.py
index 0ca5ecafbaab..444e7e010ba1 100644
--- a/homeassistant/components/iotawatt/sensor.py
+++ b/homeassistant/components/iotawatt/sensor.py
@@ -164,10 +164,16 @@ class IotaWattSensor(CoordinatorEntity[IotawattUpdater], SensorEntity):
 
         self._key = key
         data = self._sensor_data
+        # An entity without a unique ID cannot be attached to a device.
         if data.getType() == "Input":
             self._attr_unique_id = (
                 f"{data.hub_mac_address}-input-{data.getChannel()}-{data.getUnit()}"
             )
+            self._attr_device_info = dr.DeviceInfo(
+                connections={(dr.CONNECTION_NETWORK_MAC, data.hub_mac_address)},
+                manufacturer="IoTaWatt",
+                model="IoTaWatt",
+            )
         self.entity_description = entity_description
 
     @property
@@ -181,18 +187,6 @@ class IotaWattSensor(CoordinatorEntity[IotawattUpdater], SensorEntity):
         """Return name of the entity."""
         return self._sensor_data.getName()
 
-    @property
-    @override
-    def device_info(self) -> dr.DeviceInfo:
-        """Return device info."""
-        return dr.DeviceInfo(
-            connections={
-                (dr.CONNECTION_NETWORK_MAC, self._sensor_data.hub_mac_address)
-            },
-            manufacturer="IoTaWatt",
-            model="IoTaWatt",
-        )
-
     @callback
     @override
     def _handle_coordinator_update(self) -> None:
diff --git a/tests/components/iotawatt/test_sensor.py b/tests/components/iotawatt/test_sensor.py
index dbb11fe4258b..1d07e416976b 100644
--- a/tests/components/iotawatt/test_sensor.py
+++ b/tests/components/iotawatt/test_sensor.py
@@ -4,6 +4,7 @@ from datetime import timedelta
 from unittest.mock import MagicMock
 
 from freezegun.api import FrozenDateTimeFactory
+import pytest
 
 from homeassistant.components.iotawatt.const import DOMAIN
 from homeassistant.components.sensor import (
@@ -19,11 +20,12 @@ from homeassistant.const import (
     UnitOfPower,
 )
 from homeassistant.core import HomeAssistant
+from homeassistant.helpers import device_registry as dr, entity_registry as er
 from homeassistant.setup import async_setup_component
 
 from . import INPUT_SENSOR, OUTPUT_SENSOR
 
-from tests.common import async_fire_time_changed
+from tests.common import MockConfigEntry, async_fire_time_changed
 
 
 async def test_sensor_type_input(
@@ -88,3 +90,35 @@ async def test_sensor_type_output(
     await hass.async_block_till_done()
 
     assert hass.states.get("sensor.my_watthour_sensor") is None
+
+
+async def test_output_sensor_not_attached_to_device(
+    hass: HomeAssistant,
+    device_registry: dr.DeviceRegistry,
+    entity_registry: er.EntityRegistry,
+    caplog: pytest.LogCaptureFixture,
+    mock_iotawatt: MagicMock,
+    entry: MockConfigEntry,
+) -> None:
+    """Test only sensors with a unique ID are attached to the device."""
+    mock_iotawatt.getSensors.return_value["sensors"] = {
+        "my_sensor_key": INPUT_SENSOR,
+        "my_watthour_sensor_key": OUTPUT_SENSOR,
+    }
+    assert await async_setup_component(hass, DOMAIN, {})
+    await hass.async_block_till_done()
+
+    device = device_registry.async_get_device_by_connection(
+        (dr.CONNECTION_NETWORK_MAC, "mock-mac"), entry.entry_id
+    )
+    assert device is not None
+
+    input_entry = entity_registry.async_get("sensor.test_device_my_sensor")
+    assert input_entry is not None
+    assert input_entry.device_id == device.id
+
+    # Outputs have no unique ID, hence no registry entry to attach a device to.
+    assert hass.states.get("sensor.my_watthour_sensor") is not None
+    assert entity_registry.async_get("sensor.my_watthour_sensor") is None
+
+    assert "attempts to attach a device to an entity" not in caplog.text