fix(tests): resolve ruff F821 errors for DuplicateTest in test_duplicates.py

tests/test_duplicates.py

@@ -3,46 +3,41 @@
 
 import pytest
 
-#: Mock arcpy before importing the module under test
+# ruff: isort: off
+#: Mock arcpy and its submodules before importing the module under test
 arcpy_mock = MagicMock()
+_MOCK_MODULE_NAMES = [
+    "arcpy",
+    "arcpy.da",
+    "arcpy._mp",
+    "arcpy.typing",
+    "arcpy.typing.gp",
+    "xxhash",
+]
+_originals = {name: sys.modules.get(name) for name in _MOCK_MODULE_NAMES}
+sys.modules["arcpy"] = arcpy_mock
+sys.modules["arcpy.da"] = arcpy_mock.da
+sys.modules["arcpy._mp"] = arcpy_mock._mp
+sys.modules["arcpy.typing"] = arcpy_mock.typing
+sys.modules["arcpy.typing.gp"] = arcpy_mock.typing.gp
+sys.modules["xxhash"] = MagicMock()
+
+from sweeper.sweepers.duplicates import DuplicateTest  # noqa: E402
+
+# ruff: isort: on
 
 
 @pytest.fixture(autouse=True, scope="module")
-def _mock_arcpy_and_xxhash():
-    """Mock arcpy (and submodules) and xxhash for this test module only."""
-    # Save original modules so we can restore them after the tests run.
-    module_names = [
-        "arcpy",
-        "arcpy.da",
-        "arcpy._mp",
-        "arcpy.typing",
-        "arcpy.typing.gp",
-        "xxhash",
-    ]
-    originals = {name: sys.modules.get(name) for name in module_names}
-
-    # Install mocks into sys.modules for the duration of this module's tests.
-    sys.modules["arcpy"] = arcpy_mock
-    sys.modules["arcpy.da"] = arcpy_mock.da
-    sys.modules["arcpy._mp"] = arcpy_mock._mp
-    sys.modules["arcpy.typing"] = arcpy_mock.typing
-    sys.modules["arcpy.typing.gp"] = arcpy_mock.typing.gp
-    sys.modules["xxhash"] = MagicMock()
-
-    from sweeper.sweepers.duplicates import DuplicateTest as _DuplicateTest  # noqa: E402
-
-    # Expose DuplicateTest at module level so existing tests continue to work.
-    globals()["DuplicateTest"] = _DuplicateTest
-
-    try:
-        yield
-    finally:
-        # Restore the original sys.modules entries.
-        for name, original in originals.items():
-            if original is None:
-                sys.modules.pop(name, None)
-            else:
-                sys.modules[name] = original
+def _restore_sys_modules():
+    """Restore sys.modules entries modified by this module after all tests complete."""
+    yield
+    for name, original in _originals.items():
+        if original is None:
+            sys.modules.pop(name, None)
+        else:
+            sys.modules[name] = original
+
+
 class TestChunkOidList:
     def test_chunk_oid_list_small_list_returns_single_chunk(self):
         lst = [1, 2, 3]