Twenty Identical Runs, Then One Small Diff: Sealing Entropy Before a Messy Refactor
Your golden files rot because the code is not the only input. Clocks, random seeds, UUIDs, and hash order leak into output. Seal those four sources first. Then prove the suite is stable. Only after that do you record a baseline. This post is step zero of a messy-repo refactor. It is not about the refactor itself. It is about earning the right to trust a baseline at all. A characterization test compares bytes. If the bytes change for reasons unrelated to your edit, the test is noise. Noisy tests…