Part 2 - animating the scrollTop property separately during the exiting transition

Post.js

executeExitingTransition = (node, done) => {
  // we're temporarily changing our spring to
  // a tween with a very long duration to check
  // everything is working properly

  tween({
    from: this.from,
    to: this.to,
    duration: 10000
    // stiffness: 100,
    // damping: 12,
    // restDelta: true,
    // restSpeed: 0.1
  }).start({
    update: ({ scrollTop, ...rest }) => {
      this.postStyler.set(rest);
      this.postScroll.set('top', scrollTop);
    },
    complete: () => {
      this.preview.style.visibility = 'visible';

      const scrollTop = -this.pageListStyler.get('top');
      this.pageListStyler.set({ position: 'absolute', top: 0 });
      windowScroll.set('top', scrollTop);
      done();
    }
  });
};