Actions in Vanilla Redux

0_constants.js

const INCREASE_BY = 'INCREASE_BY'
const DECREASE_BY = 'DECREASE_BY'

1_actions.js

import { INCREASE_BY, DECREASE_BY } from './consts'

export const increaseBy = amount => ({
  type: INCREASE_BY,
  payload: amount
})

export const decreaseBy = amount => ({
  type: DECREASE_BY,
  payload: amount
})