Fix test isolation for clear_import_cache utility

tests/utils/test_import_utils.py

@@ -1,23 +1,28 @@
+import importlib
 import sys
 
-from transformers.utils.import_utils import clear_import_cache
+from transformers.utils.import_utils import _LazyModule, clear_import_cache
 
 
 def test_clear_import_cache():
-    # Import some transformers modules
-
-    # Get initial module count
+    # Save initial state
     initial_modules = {name: mod for name, mod in sys.modules.items() if name.startswith("transformers.")}
 
-    # Verify we have some modules loaded
-    assert len(initial_modules) > 0
-
-    # Clear cache
+    # Run the test
     clear_import_cache()
 
-    # Check modules were removed
+    # Verify modules were removed
     remaining_modules = {name: mod for name, mod in sys.modules.items() if name.startswith("transformers.")}
     assert len(remaining_modules) < len(initial_modules)
 
-    # Verify we can reimport
-    assert "transformers" in sys.modules
+    # Import and verify module exists
+    from transformers.models.auto import modeling_auto
+
+    assert modeling_auto.__name__ == "transformers.models.auto.modeling_auto"
+
+    # Restore initial state
+    for name, module in initial_modules.items():
+        sys.modules[name] = module
+        if isinstance(module, _LazyModule):
+            # Re-initialize lazy module cache
+            importlib.reload(module)