From 792060aa1c711aba42aefd6af2bac3ea31c4c950 Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@koston.org>
Date: Mon, 23 Jun 2025 17:15:15 +0200
Subject: [PATCH] cleanup

---
 homeassistant/components/esphome/manager.py |  6 +-
 tests/components/esphome/test_manager.py    | 67 +++++++++++++++++++++
 2 files changed, 70 insertions(+), 3 deletions(-)

diff --git a/homeassistant/components/esphome/manager.py b/homeassistant/components/esphome/manager.py
index c18ba62ac54..89e552bd596 100644
--- a/homeassistant/components/esphome/manager.py
+++ b/homeassistant/components/esphome/manager.py
@@ -802,8 +802,8 @@ def _async_setup_device_registry(
         )
 
     suggested_area: str | None = None
-    if device_info.area:
-        # Prefer device_info.area over suggested_area
+    if device_info.area and device_info.area.name:
+        # Prefer device_info.area over suggested_area when area name is not empty
         suggested_area = device_info.area.name
     elif device_info.suggested_area:
         suggested_area = device_info.suggested_area
@@ -830,7 +830,7 @@ def _async_setup_device_registry(
     for sub_device in device_info.devices:
         # Determine the area for this sub device
         sub_device_suggested_area: str | None = None
-        if sub_device.area_id and sub_device.area_id in areas_by_id:
+        if sub_device.area_id is not None and sub_device.area_id in areas_by_id:
             sub_device_suggested_area = areas_by_id[sub_device.area_id].name
 
         sub_device_entry = device_registry.async_get_or_create(
diff --git a/tests/components/esphome/test_manager.py b/tests/components/esphome/test_manager.py
index 492a576cf3d..a95af3f1046 100644
--- a/tests/components/esphome/test_manager.py
+++ b/tests/components/esphome/test_manager.py
@@ -1678,3 +1678,70 @@ async def test_sub_device_cleanup(
         )
         is not None
     )
+
+
+async def test_sub_device_references_main_device_area(
+    hass: HomeAssistant,
+    mock_client: APIClient,
+    mock_esphome_device: MockESPHomeDeviceType,
+) -> None:
+    """Test sub devices can reference the main device's area."""
+    device_registry = dr.async_get(hass)
+
+    # Define areas - note we don't include area_id=0 in the areas list
+    areas = [
+        AreaInfo(area_id=1, name="Living Room"),
+        AreaInfo(area_id=2, name="Bedroom"),
+    ]
+
+    # Define sub devices - one references the main device's area (area_id=0)
+    sub_devices = [
+        SubDeviceInfo(
+            device_id=11111111, name="Motion Sensor", area_id=0
+        ),  # Main device area
+        SubDeviceInfo(
+            device_id=22222222, name="Light Switch", area_id=1
+        ),  # Living Room
+        SubDeviceInfo(
+            device_id=33333333, name="Temperature Sensor", area_id=2
+        ),  # Bedroom
+    ]
+
+    device_info = {
+        "areas": areas,
+        "devices": sub_devices,
+        "area": AreaInfo(area_id=0, name="Main Hub Area"),
+    }
+
+    device = await mock_esphome_device(
+        mock_client=mock_client,
+        device_info=device_info,
+    )
+
+    # Check main device has correct area
+    main_device = device_registry.async_get_device(
+        connections={(dr.CONNECTION_NETWORK_MAC, device.device_info.mac_address)}
+    )
+    assert main_device is not None
+    assert main_device.suggested_area == "Main Hub Area"
+
+    # Check sub device 1 uses main device's area
+    sub_device_1 = device_registry.async_get_device(
+        identifiers={(DOMAIN, f"{device.device_info.mac_address}_11111111")}
+    )
+    assert sub_device_1 is not None
+    assert sub_device_1.suggested_area == "Main Hub Area"
+
+    # Check sub device 2 uses Living Room
+    sub_device_2 = device_registry.async_get_device(
+        identifiers={(DOMAIN, f"{device.device_info.mac_address}_22222222")}
+    )
+    assert sub_device_2 is not None
+    assert sub_device_2.suggested_area == "Living Room"
+
+    # Check sub device 3 uses Bedroom
+    sub_device_3 = device_registry.async_get_device(
+        identifiers={(DOMAIN, f"{device.device_info.mac_address}_33333333")}
+    )
+    assert sub_device_3 is not None
+    assert sub_device_3.suggested_area == "Bedroom"