Test migration to jest by hand

Apparently using regular expressions is way easier.

test/takeRightWhile/takeRightWhile.js

@@ -0,0 +1,6 @@
+const takeRightWhile = (arr, func) => {
+for (let i of arr.reverse().keys())
+if (func(arr[i])) return arr.reverse().slice(arr.length - i, arr.length);
+return arr;
+};
+module.exports = takeRightWhile;