diff --git a/tests/unit/services/test_cluster_state_context_domains.py b/tests/unit/services/test_cluster_state_context_domains.py
index acbed33..c946e6e 100644
--- a/tests/unit/services/test_cluster_state_context_domains.py
+++ b/tests/unit/services/test_cluster_state_context_domains.py
@@ -214,6 +214,15 @@ def test_health_anomaly_signal_profile_and_attention_domains() -> None:
     assert attention._node_attention_score(node_context[0])[0] > 0
 
 
+def test_signal_helpers_filter_empty_and_malformed_inputs(monkeypatch) -> None:
+    assert signals._node_delta_signals([None, {"node": ""}, {"node": "titan-1", "baseline_delta": {"cpu": 5.0}}]) == []
+    assert signals._namespace_delta_signals([None, {"namespace": ""}, {"namespace": "apps", "baseline_delta": {"cpu": 5.0}}]) == []
+    assert signals._kustomization_signals({}) == []
+    assert signals._pod_issue_signals("bad") == []
+    monkeypatch.setattr(signals, "_workload_not_ready_items", lambda _health: [])
+    assert signals._workload_health_signals({"deployments": {"not_ready": 0}}) == []
+
+
 def test_profile_builders_filter_bad_nodes_and_workload_nodes() -> None:
     node_profiles = profiles._node_profiles(
         [