generate new test that did already exist & update all module snippets with declaration

test/isSorted/isSorted.js

@@ -1,4 +1,4 @@
-module.exports = arr => {
+module.exports = isSorted = arr => {
 const direction = arr[0] > arr[1] ? -1 : 1;
 for (let [i, val] of arr.entries())
 if (i === arr.length - 1) return direction;