AugurProject/augur-ui

export default function(target, isOpen, callback) {
  if (isOpen) {
    const targetTransition = target.style.transition;
    target.style.transition = "";

    requestAnimationFrame(() => {
      target.style.height = target.scrollHeight + "px";
      target.style.transition = targetTransition;

      requestAnimationFrame(() => {
        target.style.height = "0px";
      });
    });
  } else {
    target.style.height = target.scrollHeight + "px";

    target.addEventListener("transitionend", function onTransitionEnd(e) {
      target.removeEventListener("transitionend", onTransitionEnd);
      target.style.height = "auto";
    });
  }

  callback();
}