Yup, this is my biggest issue with JavaScript's built-in functional utilities. It just totally ignores treating objects like dictionaries/maps. Even ES6 Maps/Sets lack functional features.
I think he's referring to `Object.keys(object).reduce`. We polyfill `Object.entries` so we do `Object.entries(object).reduce((result, [key, value]) => ...)`
>Important: Note that the native equivalents are array methods, and will not work with objects. If this functionality is needed, then Lodash/Underscore is the better option.
There's a strawman proposal out there to solve this but until then I'll be sticking with Lodash: https://github.com/leebyron/ecmascript-iterator-hof