From 839df008ff42e82d4e8d3d56e6ecca68da5c4e85 Mon Sep 17 00:00:00 2001
From: Chelsea Lin <chelsealin@google.com>
Date: Tue, 28 Jan 2025 21:07:12 +0000
Subject: [PATCH 1/2] fix: bring back ModuleNotFoundError handler in
 pandas_backports.py

---
 db_dtypes/pandas_backports.py | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/db_dtypes/pandas_backports.py b/db_dtypes/pandas_backports.py
index 8112c54..f8009ea 100644
--- a/db_dtypes/pandas_backports.py
+++ b/db_dtypes/pandas_backports.py
@@ -62,7 +62,10 @@ def import_default(module_name, force=False, default=None):
         return default
 
     name = default.__name__
-    module = __import__(module_name, {}, {}, [name])
+    try:
+        module = __import__(module_name, {}, {}, [name])
+    except ModuleNotFoundError:
+        return default
 
     return getattr(module, name, default)
 

From c5f979f722b1b2fadfb9c3311a416c7ada063875 Mon Sep 17 00:00:00 2001
From: Chelsea Lin <chelsealin@google.com>
Date: Thu, 30 Jan 2025 21:11:36 +0000
Subject: [PATCH 2/2] add unit-test for import_default functions

---
 tests/unit/test_pandas_backports.py | 37 +++++++++++++++++++++++++++++
 1 file changed, 37 insertions(+)
 create mode 100644 tests/unit/test_pandas_backports.py

diff --git a/tests/unit/test_pandas_backports.py b/tests/unit/test_pandas_backports.py
new file mode 100644
index 0000000..eb68b6a
--- /dev/null
+++ b/tests/unit/test_pandas_backports.py
@@ -0,0 +1,37 @@
+# Copyright 2024 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.
+
+import unittest.mock as mock
+
+import db_dtypes.pandas_backports as pandas_backports
+
+
+@mock.patch("builtins.__import__")
+def test_import_default_module_found(mock_import):
+    mock_module = mock.MagicMock()
+    mock_module.OpsMixin = "OpsMixin_from_module"  # Simulate successful import
+    mock_import.return_value = mock_module
+
+    default_class = type("OpsMixin", (), {})  # Dummy class
+    result = pandas_backports.import_default("module_name", default=default_class)
+    assert result == "OpsMixin_from_module"
+
+
+@mock.patch("builtins.__import__")
+def test_import_default_module_not_found(mock_import):
+    mock_import.side_effect = ModuleNotFoundError
+
+    default_class = type("OpsMixin", (), {})  # Dummy class
+    result = pandas_backports.import_default("module_name", default=default_class)
+    assert result == default_class