fix(search): retain group signal in domain grouping

Author: swissmo

src/ha_mcp/tools/tools_search.py

@@ -1389,7 +1389,7 @@ def _build_domain_only_by_domain(
     """Build the by_domain dict for domain-listing mode (all results are one domain)."""
     items = results[:per_domain_limit] if per_domain_limit is not None else results
     if parsed_result_fields is not None:
-        items = _project_records(items, parsed_result_fields)
+        items = _project_records(items, _effective_result_fields(parsed_result_fields))
     return {domain: items}
 
 

tests/src/unit/test_search_fields_projection.py

@@ -621,6 +621,26 @@ async def test_per_domain_limit_domain_listing_branch(self, search_tool):
         assert "light" in by_domain
         assert len(by_domain["light"]) <= 1
 
+    @pytest.mark.asyncio
+    async def test_domain_listing_member_only_projection_keeps_group_signal(
+        self, search_tool
+    ):
+        """Member-only domain grouping retains the group discriminator."""
+        result = await search_tool(
+            domain_filter="light",
+            group_by_domain=True,
+            result_fields=["member_entity_ids"],
+            limit=20,
+        )
+
+        expected_group = {
+            "is_group": True,
+            "member_entity_ids": ["light.member_one", "light.member_two"],
+        }
+        assert expected_group in result["entities"]
+        assert expected_group in result["by_domain"]["light"]
+        assert {"is_group": False} in result["by_domain"]["light"]
+
 
 class TestHaSearchEntitiesStateFilter(_SearchToolFixture):
     """Tests for state_filter= normalization and per-branch behavior (issue #1199)."""