Add test case for renaming non-existent files

- Test that renaming non-existent files returns 404 instead of 500
- Covers both file and directory rename scenarios
- Validates proper error message format

Author: aws-jasakshi

tests/services/contents/test_manager.py

@@ -854,6 +854,21 @@ async def test_rename(jp_contents_manager):
     await ensure_async(cm.new_untitled("foo/bar_diff", ext=".ipynb"))
 
 
+async def test_rename_nonexistent(jp_contents_manager):
+    """Test renaming a non-existent file/directory returns 404 error"""
+    cm = jp_contents_manager
+    
+    # Test with non-existent file
+    with pytest.raises(HTTPError) as e:
+        await ensure_async(cm.rename("nonexistent_file.txt", "new_name.txt"))
+    assert expected_http_error(e, 404, expected_message="File or directory does not exist: nonexistent_file.txt")
+
+    # Test with non-existent directory
+    with pytest.raises(HTTPError) as e:
+        await ensure_async(cm.rename("nonexistent_dir", "new_dir"))
+    assert expected_http_error(e, 404, expected_message="File or directory does not exist: nonexistent_dir")
+
+
 async def test_delete_root(jp_contents_manager):
     cm = jp_contents_manager
     with pytest.raises(HTTPError) as e: