🐛(back) fix management command to rename deposited files

After some tests on preprod, the management commands was not working as some
deposited files have an extension in their filename, but not in their object
storage key. Fixing the command by using the extension field instead of
computing the extension from the filename.

Author: wilbrdt

src/backend/marsha/deposit/management/commands/rename_deposited_files.py

@@ -1,7 +1,6 @@
 """Rename deposited files in Scaleway S3 for serving them with the right name."""
 
 import logging
-from os.path import splitext
 
 from django.conf import settings
 from django.core.management.base import BaseCommand
@@ -51,9 +50,7 @@ def handle(self, *args, **options):
         for file in files:
             # Get the file stored on Scaleway S3 under `aws/`
             stamp = time_utils.to_timestamp(file.uploaded_on)
-            extension = ""
-            if "." in file.filename:
-                extension = splitext(file.filename)[1]
+            extension = "." + file.extension if file.extension else ""
 
             file_key_src = file.get_storage_key(
                 filename=f"{stamp}{extension}", base_dir=AWS_STORAGE_BASE_DIRECTORY

src/backend/marsha/deposit/tests/test_command_rename_deposited_files.py

@@ -1,7 +1,6 @@
 """Test the ``rename_deposited_files`` management command."""
 
 from datetime import datetime, timezone
-from os.path import splitext
 from unittest import mock
 
 from django.core.management import call_command
@@ -43,6 +42,7 @@ def test_rename_deposited_files(self, mock_exists):
             for filename_src, _ in filenames:
                 file = DepositedFileFactory(
                     filename=filename_src,
+                    extension="pdf",
                     uploaded_on=now,
                     upload_state=READY,
                     storage_location=AWS_S3,
@@ -54,9 +54,7 @@ def test_rename_deposited_files(self, mock_exists):
             # were created, so we must iterate over objects.all() in the same sequence
             for file in DepositedFile.objects.all():
                 stamp = time_utils.to_timestamp(file.uploaded_on)
-                extension = ""
-                if "." in file.filename:
-                    extension = splitext(file.filename)[1]
+                extension = "." + file.extension if file.extension else ""
 
                 file_key_src = (
                     f"aws/{file.file_depository.id}/depositedfile/"