Test migration to jest by hand

Apparently using regular expressions is way easier.

test/flattenObject/flattenObject.js

@@ -0,0 +1,8 @@
+const flattenObject = (obj, prefix = '') =>
+Object.keys(obj).reduce((acc, k) => {
+const pre = prefix.length ? prefix + '.' : '';
+if (typeof obj[k] === 'object') Object.assign(acc, flattenObject(obj[k], pre + k));
+else acc[pre + k] = obj[k];
+return acc;
+}, {
+module.exports = flattenObject;