Jest‑Chance is a tiny helper library that wraps Chance JS to give Jest (and Vitest) tests reproducible random data. By managing a seed per test run and exposing it in the console, it lets developers write randomized, “monkey‑testing” cases that are flaky‑free and can be re‑run exactly by setting `CHANCE_SEED`. It’s aimed at JavaScript/TypeScript developers who want robust, data‑driven unit tests without sacrificing determinism.