Function yieldedDuring

__tests__/cooperative-yield.test.ts:27–32

* A `setImmediate` callback runs in the check phase — AFTER the microtask queue * drains. So if `await maybeYield()` did NOT cross a macrotask boundary (it was * under budget and returned a synchronously-resolved promise), a `setImmediate` * scheduled just before it has NOT fired yet. If it DID y

(maybeYield: () => Promise<void>)

 * This makes "did it yield?" a deterministic, non-timing assertion.
 */
async function yieldedDuring(maybeYield: () => Promise<void>): Promise<boolean> {
  let macrotaskRan = false;
  setImmediate(() => { macrotaskRan = true; });
  await maybeYield();
  return macrotaskRan;
}

describe('createYielder', () => {
  it('does not yield while under the time budget', async () => {