fix(kernels): check HTTP status when downloading outputs

[sridipbasu]

Summary

When running kaggle kernels output, the CLI downloads each output file from a signed storage URL. The response from that request was written directly to the output file without checking the HTTP status first.

Because of this, if the storage request returned an error such as 403 or 5xx, the error response itself could be saved as the output file. The CLI would then print that the file was downloaded successfully even though the file actually contained the error response.

This was especially problematic for scripts or automated workflows that rely on the command succeeding and then use the downloaded file.

Fix

Added raise_for_status() after the storage request so failed downloads are stopped before anything is written to disk.

The existing CLI error handling already handles HTTPError, so no other changes to the download flow were needed.

Also added a regression test to make sure a failed download raises the expected error and does not create the output file.

Tests

Added a test covering a failed output file download with a 403 response.

Ran:

pytest tests/unit/test_kernels_logs.py::TestKernelsLogs::test_kernels_output_failed_download_is_not_written -v

pytest tests/unit/test_kernels_logs.py -k "output" -v

pytest tests/unit -q

The regression test was also verified to fail before the fix and pass after the fix.

All unit tests pass with 1289 tests passing.

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[sridipbasu]

@google-cla
cc: @stevemessick
Just wanted to clarify: I mistakenly did this from another account. I corrected the commit author and pushed the same content from my sridipbasu account, so nothing changed in the implementation.

[stevemessick]

/gcbrun

[stevemessick]

Great! Thanks, again.