[aelde]

A FASTA file ending in a header without a sequence can silently reuse the preceding record's sequence. For example, >first\nACGT\n>missing\n returns (['first', 'missing'], ['ACGT', 'ACGT']), potentially mislabelling sequence input to gget mutate.

Reject the unfinished record with ValueError, consistent with the existing rejection of consecutive headers. Ignore blank lines so they cannot hide a missing sequence. Complete records retain their output, including multiline sequences and files without a final newline. Zero-byte file handling is unchanged.

Adds 16 synthetic regression cases and a changelog entry.

Validation (Python 3.12.3, normal package imports):

python -m pytest -q -p no:cacheprovider tests/test_read_fasta.py tests/test_utils.py::TestUtils::test_read_fasta

• Base bc7b353ea2215cba00697591c33887b1094c660b: 9 failed, 8 passed.
• With this fix: 17 passed, including the existing FASTA fixture.
• git diff --check passed. The full live-service test suite and lint/type-check matrix were not run locally.

AI assistance: OpenAI Codex assisted with investigation, implementation, tests, changelog, and this description. The human contributor reviewed and approved the missing-sequence error behavior and main validation conditions before this commit. The tests above were executed by Codex; this disclosure does not claim a human independently ran them.

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 57.02%. Comparing base (63f592f) to head (f99e145).
⚠️ Report is 4 commits behind head on dev.

Additional details and impacted files

@@            Coverage Diff             @@
##              dev     #280      +/-   ##
==========================================
+ Coverage   55.87%   57.02%   +1.14%     
==========================================
  Files          29       29              
  Lines        9392     9421      +29     
==========================================
+ Hits         5248     5372     +124     
+ Misses       4144     4049      -95     

☔ View full report in Codecov by Harness.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.