API to simplify a producer + patches

[mweststrate]

🚀 Feature Proposal

Introduce API's to capture the next state and patches directly:

• produceWithPatches(baseState, recipe) => [nextState, patches, inversePatches]
• produceWithPatches(recipe) => (baseState, ...args) => [nextState, patches, inversePaches] (curried form)

Motivation

Currently it is quite annoying to grab the patches from a producer, for two reasons:

First, directly returning is often impossible, and a lot of temporarily local vars enter the game, in order to be able to wire up the receiving both the next state and the patches. The following pattern I encounter quite reqularly:

const myCoolFunc(state) => produce(state, draft => { /* something */ })

// to capture patches, it must be destructred to :
// (this is even worse if you used a curried produce, as it has to be uncurried to be able to write the following)
const myCoolFuncWithPatches(state) => {
   let patches
   const nextState = produce(state, draft => { /* something */ }, p => { patches = p })
   return [nextState, patches]
}

// with this proposal it becomes
const myCoolFunc(state) => produceWithPatches(state, draft => { /* something */ })

cc @aleclarson