Reselect vs Vanilla

reselect.js

import { createSelector } from 'reselect';

const shopItemsSelector = state => state.shop.items;
const taxPercentSelector = state => state.shop.taxPercent;

const subtotalSelector = createSelector(
	shopItemsSelector,
	items => items.reduce((acc, item) => acc + item.value, 0)
);

const taxSelector = createSelector(
	subtotalSelector,
	taxPercentSelector,
	(subtotal, taxPercent) => subtotal * (taxPercent / 100)
);

export const totalSelector = createSelector(
	subtotalSelector,
	taxSelector,
	(subtotal, tax) => ({ total: subtotal + tax })
);

vanilla.js

const shopItemsSelector = state => state.shop.items;
const taxPercentSelector = state => state.shop.taxPercent;

const subtotalSelector = state =>
	shopItemsSelector(state).reduce((acc, item) => acc + item.value, 0);

const taxSelector = state =>
	subtotalSelector(state) * (taxPercentSelector(state) / 100);

export const totalSelector = state =>
	({ total: subtotalSelector(state) + taxSelector(state)});