Test migration to jest by hand

Apparently using regular expressions is way easier.

test/toHash/toHash.js

@@ -0,0 +1,7 @@
+const toHash = (object, key) =>
+Array.prototype.reduce.call(
+object,
+(acc, data, index) => ((acc[!key ? index : data[key]] = data), acc),
+{}
+);
+module.exports = toHash;