My Test for a Safety Guard Deleted the Real Revenue Ledger

Описание и применение

Тесты мутации на Windows PC привели к удалению реального реестра доходов. После трех инцидентов реализованы блокировки путей, тесты на несуществующие файлы и контроль изменений, что предотвратило дальнейшие потери данных.

Задача

Mutation testing on a Windows PC caused unintended deletion of real revenue ledger files, creating data loss.

Результат

Implemented path‑blocking guard and test adjustments prevented further ledger deletions and ensured mutation testing does not affect production data.

Рабочий процесс

• Run mutation testing on temporary code copy
• Execute tests that call real browser script and ledger writer
• Detect unintended writes/deletions to real data folder
• Implement guard to refuse writes/deletes under real data folder
• Adjust tests to target non‑existent paths
• Snapshot data folder before/after each mutant
• Rebuild ledger from runner logs if deletion occurs

Доказательства

The edits happen in a temporary copy of the code. That felt safe. It wasn't, because the copy was only a copy of the code.

Источник

Later that day a mutation slipped past a test's fake recording function. The real one ran and wrote test values into the real daily revenue ledger.

Источник

The mutant without the delete check ran os.unlink on the real ledger at 16:34.

Источник