fix: support home discovery when there are no maps (#809)

* fix: support home discovery when there are no maps

* test: update home discovery test to verify refresh behavior and state consistency

Author: allenporter

roborock/devices/traits/v1/home.py

@@ -107,7 +107,10 @@ async def discover_home(self) -> None:
 
         await self._maps_trait.refresh()
         if self._maps_trait.current_map_info is None:
-            raise RoborockException("Cannot perform home discovery without current map info")
+            _LOGGER.debug("Cannot perform home discovery without current map info")
+            self._discovery_completed = True
+            await self._update_home_cache({}, {})
+            return
 
         home_map_info, home_map_content = await self._build_home_map_info()
         _LOGGER.debug("Home discovery complete, caching data for %d maps", len(home_map_info))
@@ -198,7 +201,8 @@ async def refresh(self) -> None:
         if (current_map_info := self._maps_trait.current_map_info) is None or (
             map_flag := self._maps_trait.current_map
         ) is None:
-            raise RoborockException("Cannot refresh home data without current map info")
+            _LOGGER.debug("Cannot refresh home data without current map info")
+            return
 
         # Refresh the map content to ensure we have the latest image and object positions
         new_map_content = await self._refresh_map_content()

tests/devices/traits/v1/test_home.py

@@ -367,11 +367,25 @@ async def test_discover_home_no_maps(
     """Test discovery when no maps are available."""
     # Setup mock to return empty maps list
     mock_mqtt_rpc_channel.send_command.side_effect = [
-        [{"max_multi_map": 0, "max_bak_map": 0, "multi_map_count": 0, "map_info": []}]
+        # Discover home
+        [{"max_multi_map": 0, "max_bak_map": 0, "multi_map_count": 0, "map_info": []}],
+        # Refresh
+        [{"max_multi_map": 0, "max_bak_map": 0, "multi_map_count": 0, "map_info": []}],
     ]
 
-    with pytest.raises(Exception, match="Cannot perform home discovery without current map info"):
-        await home_trait.discover_home()
+    # Discover home should not change anything
+    await home_trait.discover_home()
+    assert home_trait.current_map_data is None
+    assert home_trait.home_map_info == {}
+    assert home_trait.home_map_content == {}
+    assert home_trait.current_rooms == []
+
+    # Refresh should not change anything
+    await home_trait.refresh()
+    assert home_trait.current_map_data is None
+    assert home_trait.home_map_info == {}
+    assert home_trait.home_map_content == {}
+    assert home_trait.current_rooms == []
 
 
 async def test_refresh_updates_current_map_cache(