Applies the given reducer to each group in the given Grouping, returning the results together with the respective group keys

import { reduceGroups } from "https://deno.land/std@0.131.0/collections/mod.ts"
import { assertEquals } from "https://deno.land/std@0.131.0/testing/asserts.ts";

const votes = {
    'Woody': [ 2, 3, 1, 4 ],
    'Buzz': [ 5, 9 ],
}
const totalVotes = reduceGroups(votes, (sum, it) => sum + it, 0)

assertEquals(totalVotes, {
    'Woody': 10,
    'Buzz': 14,
})