Reduce with deconstruction or forEach - Iteration and Airbnb JavaScript Style Guide

I have an object: things = { table: 'red', chair: 'green' } Adhering to Airbnb's JavaScript Style Guide, I want to create a function that duplicates this object, setting all keys of the object to blue. My 2 options seem to be: 1 Use reduce function alwaysBlue(things) { return Object.keys(things) .reduce((acc, thing) => ({ ...acc, [thing]: 'blue' }), {}) } 2 Use forEach function alwaysBlue(things) { const blueThings = {} Object.keys(things) .forEach(thing => (blueThings[thing] = 'blue')) return blueThings } (1) deconstruction on every iteration seems expensive, but if I'm to take no-param-reassign in to account I can't just append to the accumulator on each iteration However, forEach (2) should be avoided in favour of map() / every() / filter() / find() / findIndex() / reduce() / some(), according to https://github.com/airbnb/javascript#iterators--nope So which is the preferred approach if I'm to adhere to Airbnb's JavaScript Style Guide - or is there another approach I'm missing?