[sophiecarreras]

Summary

• file download printed "Checksum matches" before the download completed, and even with --skip-hash-verification. It now prints after the data is saved and verified, and never when verification is skipped.
• The unit-test harness mock _TqdmCloser.__exit__ returned a truthy MagicMock, which silently swallowed exceptions from any command using a progress bar. It now returns None. Two tests that depended on the swallowing now suppress the expected KeyError explicitly.
• Adds or strengthens unit tests for: rm by file id, incremental upload, destination SSE on the wire, unbound-stream --part-size, sync thread options, sdkharness health and conformance negative paths, camelCase rejection in v4, download-file-by-name flags, rm progress, arg-parser and sdkharness file-lifecycle coverage.

Test plan

• pytest test/unit: 621 passed, 6 failed. The 6 are in test_autocomplete_cache.py and fail identically on the unmodified base in my environment; I did not investigate the cause.
• ruff check and ruff format --check pass on the changed files. Integration tests (need B2 credentials) were not run.
• The findings came from an automated review and have not been confirmed by a maintainer yet; please treat the fixes as proposals.

🤖 Generated with Claude Code

[sophiecarreras]

Review request from Sofia (drafted with Claude). Nothing in this review has been checked by a human yet; the numbers come from an agent review of whole main. Please verify, in this order:

1. For each new or changed test, revert the production line it covers (or the named fix) and confirm the test fails. A test that still passes is a finding.
2. No production behavior changed beyond what the description says.
3. The decision or check listed for this PR below.
   Reply on the linked issue if a finding is a real bug, not a bug, or already known.

This PR: Snyk Code reports one new issue that is not yet identified (someone with Snyk access needs to open it). 6 to 8 tests in test_autocomplete_cache.py fail on the unmodified base too, cause unknown.