Function withStepLimitSentinel

test/compute-engine/fungrim-loops.test.ts:100–112

* Run `fn` with a console.warn spy and assert the MAX_SIMPLIFY_STEPS guard * never trips (i.e. every simplification stayed below the iteration limit).

(fn: () => T)

 * never trips (i.e. every simplification stayed below the iteration limit).
 */
function withStepLimitSentinel<T>(fn: () => T): T {
  const warn = jest.spyOn(console, 'warn').mockImplementation(() => {});
  try {
    const result = fn();
    const tripped = warn.mock.calls.filter((args) =>
      STEP_LIMIT_WARNING.test(args.map(String).join(' '))
    );
    expect(tripped).toEqual([]);
    return result;
  } finally {
    warn.mockRestore();
  }
}

/**
 * simplify(simplify(x)): assert termination within the time budget, a stable