From d007827406dd0210f0f4acbb47559873fef20d23 Mon Sep 17 00:00:00 2001
From: Erik Montnemery <erik@montnemery.com>
Date: Mon, 5 Oct 2026 16:25:43 +0100
Subject: [PATCH] Fix entity removal leaks in upb (#183866)

---
 homeassistant/components/upb/entity.py |   3 +
 tests/components/upb/test_light.py     | 111 +++++++++++++++++++++++++
 2 files changed, 114 insertions(+)
 create mode 100644 tests/components/upb/test_light.py

diff --git a/homeassistant/components/upb/entity.py b/homeassistant/components/upb/entity.py
index e71c55c06e81..c45f4d924f6e 100644
--- a/homeassistant/components/upb/entity.py
+++ b/homeassistant/components/upb/entity.py
@@ -52,6 +52,9 @@ class UpbEntity(Entity):
     async def async_added_to_hass(self) -> None:
         """Register callback for UPB changes and update entity state."""
         self._element.add_callback(self._element_callback)
+        self.async_on_remove(
+            lambda: self._element.remove_callback(self._element_callback)
+        )
         self._element_callback(self._element, {})
 
 
diff --git a/tests/components/upb/test_light.py b/tests/components/upb/test_light.py
new file mode 100644
index 000000000000..c7b6b91a52c6
--- /dev/null
+++ b/tests/components/upb/test_light.py
@@ -0,0 +1,111 @@
+"""The light tests for the UPB platform."""
+
+from collections.abc import Generator
+from unittest.mock import AsyncMock, MagicMock, patch
+
+import pytest
+from upb_lib.devices import UpbAddr, UpbDevice
+
+from homeassistant.components.upb.const import DOMAIN
+from homeassistant.const import (
+    CONF_DEVICE,
+    CONF_FILE_PATH,
+    STATE_OFF,
+    STATE_ON,
+    Platform,
+)
+from homeassistant.core import HomeAssistant
+from homeassistant.helpers import entity_registry as er
+
+from tests.common import MockConfigEntry
+
+LIGHT_ENTITY_ID = "light.test_light"
+
+
+@pytest.fixture
+def mock_upb_device() -> UpbDevice:
+    """Return a UPB device element."""
+    device = UpbDevice(UpbAddr(1, 2, 0), MagicMock())
+    device.name = "Test light"
+    device.status = 0
+    device.dimmable = True
+    # Spy on the public callback API while keeping the real behavior.
+    device.add_callback = MagicMock(wraps=device.add_callback)
+    device.remove_callback = MagicMock(wraps=device.remove_callback)
+    return device
+
+
+@pytest.fixture
+def mock_upb(mock_upb_device: UpbDevice) -> Generator[MagicMock]:
+    """Mock the UPB PIM with a single device."""
+    with (
+        patch("homeassistant.components.upb.PLATFORMS", [Platform.LIGHT]),
+        patch("homeassistant.components.upb.upb_lib.UpbPim") as mock_pim_cls,
+    ):
+        upb = mock_pim_cls.return_value
+        upb.load_upstart_file = AsyncMock()
+        upb.async_connect = AsyncMock()
+        upb.is_connected.return_value = True
+        upb.devices = {mock_upb_device.index: mock_upb_device}
+        upb.links = {}
+        yield upb
+
+
+async def setup_integration(hass: HomeAssistant) -> MockConfigEntry:
+    """Set up the UPB integration."""
+    entry = MockConfigEntry(
+        domain=DOMAIN,
+        data={CONF_DEVICE: "tcp://1.2.3.4", CONF_FILE_PATH: "upb.upe"},
+        version=1,
+        minor_version=3,
+        unique_id="42",
+    )
+    entry.add_to_hass(hass)
+    assert await hass.config_entries.async_setup(entry.entry_id)
+    await hass.async_block_till_done()
+    return entry
+
+
+@pytest.mark.usefixtures("mock_upb")
+async def test_element_callback_removed_with_entity(
+    hass: HomeAssistant,
+    entity_registry: er.EntityRegistry,
+    mock_upb_device: UpbDevice,
+) -> None:
+    """Test removing the entity removes its element callback."""
+    await setup_integration(hass)
+    assert hass.states.get(LIGHT_ENTITY_ID)
+    mock_upb_device.add_callback.assert_called_once()
+    mock_upb_device.remove_callback.assert_not_called()
+    element_callback = mock_upb_device.add_callback.call_args.args[0]
+
+    entity_registry.async_remove(LIGHT_ENTITY_ID)
+    await hass.async_block_till_done()
+
+    assert hass.states.get(LIGHT_ENTITY_ID) is None
+    mock_upb_device.remove_callback.assert_called_once_with(element_callback)
+
+
+@pytest.mark.usefixtures("mock_upb")
+async def test_element_callback_not_duplicated_on_readd(
+    hass: HomeAssistant,
+    entity_registry: er.EntityRegistry,
+    mock_upb_device: UpbDevice,
+) -> None:
+    """Test re-adding the entity does not leave a stale element callback."""
+    await setup_integration(hass)
+    element_callback = mock_upb_device.add_callback.call_args.args[0]
+
+    # Changing the entity_id removes and re-adds the same entity object.
+    entity_registry.async_update_entity(
+        LIGHT_ENTITY_ID, new_entity_id="light.renamed_light"
+    )
+    await hass.async_block_till_done()
+
+    assert mock_upb_device.add_callback.call_count == 2
+    mock_upb_device.remove_callback.assert_called_once_with(element_callback)
+
+    assert hass.states.get("light.renamed_light").state == STATE_OFF
+    # The element still notifies the re-added entity.
+    mock_upb_device.setattr("status", 100)
+    assert hass.states.get("light.renamed_light").state == STATE_ON