/**
 * Test-only DSL for the Elm-store idiom (CLAUDE.md #3). A fixture is built by
 * replaying real `Msg`s through the real `reduce` — never by hand-assembling a
 * state object field-by-field. That closes off illegal states the reducer would
 * never actually produce: if a spec can't reach a state via messages, it can't
 * assert on it either.
 *
 * `given(reduce, initial)` partially applies a machine's reducer + starting
 * state; the result is a variadic replay function a spec calls with the exact
 * message sequence a real user/flow would send.
 */
export const given =
  <S, M>(reduce: (s: S, m: M) => S, initial: S) =>
  (...msgs: M[]): S =>
    msgs.reduce(reduce, initial);