Test migration to jest by hand

Apparently using regular expressions is way easier.

test/memoize/memoize.js

@@ -0,0 +1,9 @@
+const 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);
+};
+cached.cache = cache;
+return cached;
+};
+module.exports = memoize;