Function push

src/browser/testUtils.ts:90–102

(value: T)

  return {
    iterable,
    push(value: T) {
      if (closed) {
        return;
      }

      const resolve = pending.shift();
      if (resolve) {
        resolve({ value, done: false });
        return;
      }

      buffered.push(value);
    },
    close,
  };
}