Add unit tests for 'aggregate_clients_data_info'.

test/main/test_data_info.py

+# coding: utf-8
+
+# Copyright 2023 Inria (Institut National de Recherche en Informatique
+# et Automatique)
+#
+# 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.
+
+"""Unit tests for 'declearn.main.utils.aggregate_clients_data_info'."""
+
+from unittest import mock
+
+import pytest
+
+from declearn.main.utils import AggregationError, aggregate_clients_data_info
+
+
+class TestAggregateClientsDataInfo:
+    """Unit tests for 'declearn.main.utils.aggregate_clients_data_info'."""
+
+    def test_with_valid_inputs(self) -> None:
+        """Test 'aggregate_clients_data_info' with valid inputs."""
+        clients_data_info = {
+            "client_a": {"n_samples": 10},
+            "client_b": {"n_samples": 32},
+        }
+        results = aggregate_clients_data_info(clients_data_info, {"n_samples"})
+        assert results == {"n_samples": 42}
+
+    def test_with_missing_fields(self) -> None:
+        """Test 'aggregate_clients_data_info' with some missing fields."""
+        clients_data_info = {
+            "client_a": {"n_samples": 10},
+            "client_b": {"n_samples": 32},
+        }
+        with pytest.raises(AggregationError):
+            aggregate_clients_data_info(
+                clients_data_info,
+                required_fields={"n_samples", "features_shape"},
+            )
+
+    def test_with_invalid_values(self) -> None:
+        """Test 'aggregate_clients_data_info' with some invalid values."""
+        clients_data_info = {
+            "client_a": {"n_samples": 10},
+            "client_b": {"n_samples": -1},
+        }
+        with pytest.raises(AggregationError):
+            aggregate_clients_data_info(
+                clients_data_info, required_fields={"n_samples"}
+            )
+
+    def test_with_incompatible_values(self) -> None:
+        """Test 'aggregate_clients_data_info' with some incompatible values."""
+        clients_data_info = {
+            "client_a": {"features_shape": (100,)},
+            "client_b": {"features_shape": (128,)},
+        }
+        with pytest.raises(AggregationError):
+            aggregate_clients_data_info(
+                clients_data_info, required_fields={"features_shape"}
+            )
+
+    def test_with_unexpected_keyerror(self) -> None:
+        """Test 'aggregate_clients_data_info' with an unforeseen KeyError."""
+        with mock.patch(
+            "declearn.main.utils._data_info.aggregate_data_info"
+        ) as patch_agg:
+            patch_agg.side_effect = KeyError("Forced KeyError")
+            with pytest.raises(AggregationError):
+                aggregate_clients_data_info(
+                    clients_data_info={"client_a": {}, "client_b": {}},
+                    required_fields=set(),
+                )
+
+    def test_with_unexpected_exception(self) -> None:
+        """Test 'aggregate_clients_data_info' with an unforeseen Exception."""
+        with mock.patch(
+            "declearn.main.utils._data_info.aggregate_data_info"
+        ) as patch_agg:
+            patch_agg.side_effect = Exception("Forced Exception")
+            with pytest.raises(AggregationError):
+                aggregate_clients_data_info(
+                    clients_data_info={"client_a": {}, "client_b": {}},
+                    required_fields=set(),
+                )