Travis build: 1358 [cron]

test/invertKeyValues/invertKeyValues.js

@@ -1,6 +1,8 @@
-const invertKeyValues = obj =>
+const invertKeyValues = (obj, fn) =>
 Object.keys(obj).reduce((acc, key) => {
-acc[obj[key]] = key;
+const val = fn ? fn(obj[key]) : obj[key];
+acc[val] = acc[val] || [];
+acc[val].push(key);
 return acc;
 }, {});
  module.exports = invertKeyValues