Currently, there are no tests to ensure that when TabBarView is warping, the last frame of _pageController.animateToPage is built before the final page swapping is completed. This used to cause an exception to be thrown with nested TabBarViews (see #31581 for context).

There could probably be a robust fix to ScrollPosition.animateTo to ensure that the last frame is built prior to completing the animation, and a test to verify that this occurs properly.