reduceAll.js

// lodash - reduceAll/Assign (using fp/over)

const fp = require("lodash@4.16.6/fp");

let data = [{valA: 1, valB: 2}, {valA: 2, valB: 3}];

const reduce1 = fp.sumBy('valA');
const reduce2 = fp.sumBy('valB');
const reducers = [reduce1, reduce2];
const reducedKeys = ['sumA', 'sumB'];

const zipObjectOver = data => fp.zipObject(reducedKeys, fp.over(reducers)(data));
const mapAssign = (val, data) => fp.map(i => fp.assign(i, val))(data);
const mapAssignOver = data => mapAssign(zipObjectOver(data), data);

let result = mapAssignOver(data);