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

test/flattenDepth/flattenDepth.js

@@ -1,4 +1,4 @@
-module.exports = (arr, depth = 1) =>
+module.exports = flattenDepth = (arr, depth = 1) =>
 depth != 1
 ? arr.reduce((a, v) => a.concat(Array.isArray(v) ? flattenDepth(v, depth - 1) : v), [])
 : arr.reduce((a, v) => a.concat(v), []);