Hyperapp#v2 actions composition

compose.js

/*

Implements actions composition for Hyperapp#v2

Usage examples:

const actionA = state => ({ property: 'A' })
const actionB = state => ({ property: state.property + 'B' })

const composition = compose(actionA, actionB)
composition({}) // { property: 'AB' }

In case your actions return effects, or parameterized actions
please use 'trigger' function to compose actions

const actionA = (state, param) => ({ param })
const actionB = state => [actionA, 'foo']
const actionC = state => ({...state, c: true})

const composition = trigger(actionB, actionC)
composition({}) // { param: 'foo', c: true }

*/

export const compose = (...actions) => (state, ...args) =>
  actions.reduce((res, action) => action(res, ...args), state)

export const trigger = (...actions) => (state, ...args) =>
  [state, { effect: (_, dispatch) => actions.map(action =>
    dispatch(s => action(s, ...args))) }]