feat: GenAI Client(evals) - add user-facing generate_loss_clusters with LRO polling and replay tests

PiperOrigin-RevId: 893874547

Author: vertex-sdk-bot

tests/unit/vertexai/genai/replays/test_generate_loss_clusters.py

@@ -0,0 +1,74 @@
+# Copyright 2026 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# pylint: disable=protected-access,bad-continuation,missing-function-docstring
+
+from tests.unit.vertexai.genai.replays import pytest_helper
+from vertexai import types
+import pytest
+
+
+def test_gen_loss_clusters(client):
+    """Tests that generate_loss_clusters() returns GenerateLossClustersResponse."""
+    eval_result = types.EvaluationResult()
+    response = client.evals.generate_loss_clusters(
+        eval_result=eval_result,
+        config=types.LossAnalysisConfig(
+            metric="multi_turn_task_success_v1",
+            candidate="travel-agent",
+        ),
+    )
+    assert isinstance(response, types.GenerateLossClustersResponse)
+    assert len(response.results) == 1
+    result = response.results[0]
+    assert result.config.metric == "multi_turn_task_success_v1"
+    assert result.config.candidate == "travel-agent"
+    assert len(result.clusters) == 2
+    assert result.clusters[0].cluster_id == "cluster-1"
+    assert result.clusters[0].taxonomy_entry.l1_category == "Tool Calling"
+    assert result.clusters[0].taxonomy_entry.l2_category == "Missing Tool Invocation"
+    assert result.clusters[0].item_count == 3
+    assert result.clusters[1].cluster_id == "cluster-2"
+    assert result.clusters[1].taxonomy_entry.l1_category == "Hallucination"
+    assert result.clusters[1].item_count == 2
+
+
+pytest_plugins = ("pytest_asyncio",)
+
+
+@pytest.mark.asyncio
+async def test_gen_loss_clusters_async(client):
+    """Tests that generate_loss_clusters() async returns GenerateLossClustersResponse."""
+    eval_result = types.EvaluationResult()
+    response = await client.aio.evals.generate_loss_clusters(
+        eval_result=eval_result,
+        config=types.LossAnalysisConfig(
+            metric="multi_turn_task_success_v1",
+            candidate="travel-agent",
+        ),
+    )
+    assert isinstance(response, types.GenerateLossClustersResponse)
+    assert len(response.results) == 1
+    result = response.results[0]
+    assert result.config.metric == "multi_turn_task_success_v1"
+    assert len(result.clusters) == 2
+    assert result.clusters[0].cluster_id == "cluster-1"
+    assert result.clusters[1].cluster_id == "cluster-2"
+
+
+pytestmark = pytest_helper.setup(
+    file=__file__,
+    globals_for_file=globals(),
+    test_method="evals.generate_loss_clusters",
+)