Test migration to jest by hand

Apparently using regular expressions is way easier.

test/scrollToTop/scrollToTop.js

@@ -0,0 +1,8 @@
+const scrollToTop = () => {
+const c = document.documentElement.scrollTop || document.body.scrollTop;
+if (c > 0) {
+window.requestAnimationFrame(scrollToTop);
+window.scrollTo(0, c - c / 8);
+}
+};
+module.exports = scrollToTop;