fix: Uninitialized local #1999

Annotating local temp_file_name variable is simple than
to annotate temp_file.

Fixes #1999

Signed-off-by: Dhaval Shah <30974879+dhavalgshah@users.noreply.github.com>

Author: dhavalgshah

tuf/ngclient/updater.py

@@ -37,7 +37,7 @@
 import os
 import shutil
 import tempfile
-from typing import Any, Optional, Set
+from typing import Optional, Set
 from urllib import parse
 
 from tuf.api import exceptions
@@ -275,22 +275,23 @@ def _load_local_metadata(self, rolename: str) -> bytes:
 
     def _persist_metadata(self, rolename: str, data: bytes) -> None:
         """Write metadata to disk atomically to avoid data loss."""
-        temp_file: Optional[tempfile._TemporaryFileWrapper[Any]] = None
+        temp_file_name: Optional[str] = None
         try:
             # encode the rolename to avoid issues with e.g. path separators
             encoded_name = parse.quote(rolename, "")
             filename = os.path.join(self._dir, f"{encoded_name}.json")
             with tempfile.NamedTemporaryFile(
                 dir=self._dir, delete=False
             ) as temp_file:
+                temp_file_name = temp_file.name
                 temp_file.write(data)
             os.replace(temp_file.name, filename)
         except OSError as e:
             # remove tempfile if we managed to create one,
             # then let the exception happen
-            if temp_file is not None:
+            if temp_file_name is not None:
                 try:
-                    os.remove(temp_file.name)
+                    os.remove(temp_file_name)
                 except FileNotFoundError:
                     pass
             raise e