refactor: Share GuideLLM dashboard postprocessing

projects/caliper/engine/kpi/format.py

@@ -63,8 +63,10 @@ def transform_kpis_to_hierarchical_format(kpis: list[dict], model) -> dict:
             if k not in ("higher_is_better",) and k not in varying_keys
         }
 
-        if not test_data["labels"]:
-            test_data["labels"] = test_labels
+        # KPI handlers may add project-specific labels only to a subset of the
+        # records. Preserve every label that is constant for this test instead
+        # of freezing the set from whichever KPI happened to be emitted first.
+        test_data["labels"].update(test_labels)
 
         # Store test metadata from first KPI
         if not test_data["metadata"]:

projects/caliper/tests/test_kpi_format.py

@@ -0,0 +1,28 @@
+from __future__ import annotations
+
+from projects.caliper.engine.kpi.format import transform_kpis_to_hierarchical_format
+
+
+def test_hierarchical_format_merges_common_labels_from_all_kpis():
+    kpis = [
+        {
+            "run_id": "run-1",
+            "kpi_id": "generic",
+            "value": 1,
+            "labels": {"model": "llama"},
+        },
+        {
+            "run_id": "run-1",
+            "kpi_id": "dashboard",
+            "value": 2,
+            "labels": {"model": "llama", "tensor_parallel_size": "2"},
+        },
+    ]
+    model = type("Model", (), {"plugin_module": "missing.plugin"})()
+
+    output = transform_kpis_to_hierarchical_format(kpis, model)
+
+    assert output["tests"][0]["labels"] == {
+        "model": "llama",
+        "tensor_parallel_size": "2",
+    }