fix: address PR CoplayDev#804 review feedback

- Store asyncio.create_task reference in module-level set to prevent GC (CodeRabbit)
- Add test for _get_frontmost_app() returning None (CodeRabbit nitpick)
- Add comment explaining why prefab root rename is not tested (Sourcery)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: dsarno

Server/src/services/tools/run_tests.py

@@ -21,6 +21,9 @@
 
 logger = logging.getLogger(__name__)
 
+# Strong references to background fire-and-forget tasks to prevent premature GC.
+_background_tasks: set[asyncio.Task] = set()
+
 
 async def _get_unity_project_path(unity_instance: str | None) -> str | None:
     """Get the project root path for a Unity instance (for focus nudging).
@@ -333,6 +336,8 @@ async def _fetch_status() -> dict[str, Any]:
         ):
             logger.info(f"Test job {job_id} appears stalled (unfocused Unity), scheduling background nudge...")
             project_path = await _get_unity_project_path(unity_instance)
-            asyncio.create_task(nudge_unity_focus(unity_project_path=project_path))
+            task = asyncio.create_task(nudge_unity_focus(unity_project_path=project_path))
+            _background_tasks.add(task)
+            task.add_done_callback(_background_tasks.discard)
 
     return GetTestJobResponse(**response)

Server/tests/test_focus_nudge.py

@@ -84,6 +84,13 @@ async def test_skips_when_unity_already_focused(self):
             result = await nudge_unity_focus(force=True)
             assert result is False
 
+    @pytest.mark.asyncio
+    async def test_skips_when_frontmost_app_unknown(self):
+        with patch("utils.focus_nudge._is_available", return_value=True), \
+             patch("utils.focus_nudge._get_frontmost_app", return_value=None):
+            result = await nudge_unity_focus(force=True)
+            assert result is False
+
     @pytest.mark.asyncio
     async def test_rate_limited_by_backoff(self):
         import utils.focus_nudge as fn

TestProjects/UnityMCPTests/Assets/Tests/EditMode/Tools/ManagePrefabsCrudTests.cs

@@ -886,6 +886,8 @@ public void ModifyContents_ComponentProperties_ReturnsErrorForInvalidType()
             }
         }
 
+        // Note: root rename is NOT tested here because LoadAssetAtPath<GameObject> returns
+        // the asset filename as .name for prefab roots, so rename assertions always fail.
         [Test]
         public void ModifyContents_ComponentProperties_CombinesWithOtherModifications()
         {