chore: import upstream snapshot with attribution

tests/unittests/evaluation/test_custom_metric_evaluator.py

@@ -0,0 +1,110 @@
+# 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.
+
+from unittest import mock
+
+from google.adk.evaluation.custom_metric_evaluator import _CustomMetricEvaluator
+from google.adk.evaluation.custom_metric_evaluator import _get_metric_function
+from google.adk.evaluation.eval_case import ConversationScenario
+from google.adk.evaluation.eval_case import Invocation
+from google.adk.evaluation.eval_metrics import EvalMetric
+from google.adk.evaluation.evaluator import EvaluationResult
+import pytest
+
+
+def my_sync_metric_function(
+    eval_metric: EvalMetric,
+    actual_invocations: list[Invocation],
+    expected_invocations: list[Invocation] | None,
+    conversation_scenario: ConversationScenario | None,
+) -> EvaluationResult:
+  """Sync metric function for testing."""
+  return EvaluationResult(overall_score=1.0)
+
+
+async def my_async_metric_function(
+    eval_metric: EvalMetric,
+    actual_invocations: list[Invocation],
+    expected_invocations: list[Invocation] | None,
+    conversation_scenario: ConversationScenario | None,
+) -> EvaluationResult:
+  """Async metric function for testing."""
+  return EvaluationResult(overall_score=0.5)
+
+
+@mock.patch("importlib.import_module")
+def test_get_metric_function_success(mock_import_module):
+  """Tests that _get_metric_function successfully returns a function."""
+  mock_module = mock.MagicMock()
+  mock_module.my_sync_metric_function = my_sync_metric_function
+  mock_import_module.return_value = mock_module
+  func = _get_metric_function(
+      "test_custom_metric_evaluator.my_sync_metric_function"
+  )
+  assert func == my_sync_metric_function
+
+
+@mock.patch("importlib.import_module", side_effect=ImportError)
+def test_get_metric_function_module_not_found(mock_import_module):
+  """Tests that _get_metric_function raises ImportError for non-existent module."""
+  with pytest.raises(ImportError):
+    _get_metric_function("non_existent_module.my_sync_metric_function")
+
+
+@mock.patch("importlib.import_module")
+def test_get_metric_function_function_not_found(mock_import_module):
+  """Tests that _get_metric_function raises ImportError for non-existent function."""
+  mock_import_module.return_value = object()
+  with pytest.raises(ImportError):
+    _get_metric_function(
+        "google.adk.tests.unittests.evaluation.test_custom_metric_evaluator.non_existent_function"
+    )
+
+
+def test_get_metric_function_malformed_path():
+  """Tests that _get_metric_function raises ImportError for malformed path."""
+  with pytest.raises(ImportError):
+    _get_metric_function("malformed_path")
+
+
+@mock.patch(
+    "google.adk.evaluation.custom_metric_evaluator._get_metric_function",
+    return_value=my_sync_metric_function,
+)
+@pytest.mark.asyncio
+async def test_custom_metric_evaluator_sync_function(mock_get_metric_function):
+  """Tests that _CustomMetricEvaluator works with a sync metric function."""
+  eval_metric = EvalMetric(metric_name="sync_metric")
+  evaluator = _CustomMetricEvaluator(
+      eval_metric=eval_metric,
+      custom_function_path="google.adk.tests.unittests.evaluation.test_custom_metric_evaluator.my_sync_metric_function",
+  )
+  result = await evaluator.evaluate_invocations([], None)
+  assert result.overall_score == 1.0
+
+
+@mock.patch(
+    "google.adk.evaluation.custom_metric_evaluator._get_metric_function",
+    return_value=my_async_metric_function,
+)
+@pytest.mark.asyncio
+async def test_custom_metric_evaluator_async_function(mock_get_metric_function):
+  """Tests that _CustomMetricEvaluator works with an async metric function."""
+  eval_metric = EvalMetric(metric_name="async_metric")
+  evaluator = _CustomMetricEvaluator(
+      eval_metric=eval_metric,
+      custom_function_path="google.adk.tests.unittests.evaluation.test_custom_metric_evaluator.my_async_metric_function",
+  )
+  result = await evaluator.evaluate_invocations([], None)
+  assert result.overall_score == 0.5