DatasetFileDocument.get_presigned_url silently returns None when response lacks presignedUrl

[Yicong-Huang]

What happened?

amber/src/main/python/pytexera/storage/dataset_file_document.py::DatasetFileDocument.get_presigned_url does response.json().get("presignedUrl"), so a 200 response that omits the presignedUrl field silently returns None instead of raising. read_file then calls requests.get(None) and the caller gets a less-actionable error than the explicit-status path.

How to reproduce?

import os
from unittest.mock import patch, MagicMock
from pytexera.storage.dataset_file_document import DatasetFileDocument

os.environ["USER_JWT_TOKEN"] = "t"
os.environ["FILE_SERVICE_GET_PRESIGNED_URL_ENDPOINT"] = "http://x"

doc = DatasetFileDocument("/o/d/v/f.csv")
with patch("pytexera.storage.dataset_file_document.requests.get") as g:
    g.return_value = MagicMock(status_code=200, **{"json.return_value": {}, "text": "{}"})
    print(doc.get_presigned_url())  # prints None instead of raising

Version

1.1.0-incubating (Pre-release/Master)

[Ma77Ball]

/take