A small CLI reads config.json , changes one field, and writes the file back. The code looks harmless: await writeFile ( path , JSON . stringify ( next , null , 2 )); Then the process is interrupted during the write. The next run finds 347 bytes of what used to be a 2 KB file, JSON parsing fails, and a one-line settings command has become a recovery exercise. The useful contract is not “the write usually succeeds.” It is: After an interruption, the c...