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

test/memoize/memoize.js

@@ -1,4 +1,4 @@
-module.exports = fn => {
+module.exports = memoize = fn => {
 const cache = new Map();
 const cached = function(val) {
 return cache.has(val) ? cache.get(val) : cache.set(val, fn.call(this, val)) && cache.get(val);