The **resettable** library provides lightweight utilities for tracking and undo‑ing changes to JavaScript objects. It can generate a JSON‑Patch‑like diff between a modified object and its original state, test whether a given path is safe to modify, and apply the diff to restore the object—using relaxed rules that tolerate missing or reordered array elements. It’s aimed at developers who need a simple way to revert auto‑generated or programmatic configuration files (e.g., `package.json`) without dealing with the full JSON Patch specification.