mweststrate

const byId = produce((draft, action) => {
  switch (action.type) {
    case RECEIVE_PRODUCTS:
      action.products.forEach(product => {
        draft[product.id] = product
      })
      break
  }
})

mweststrate

// ImmutableJS
const newMap = map.updateIn(['inMap', 'inList'], list => list.push(4))

// Immer
draft.inMap.inList.push(4)

mweststrate

const byId = (state, action) =>
  produce(state, draft => {
    switch (action.type) {
      case RECEIVE_PRODUCTS:
        action.products.forEach(product => {
          draft[product.id] = product
        })
        break
    }
  })

mweststrate

// Shortened, based on: https://github.com/reactjs/redux/blob/master/examples/shopping-cart/src/reducers/products.js
const byId = (state, action) => {
  switch (action.type) {
    case RECEIVE_PRODUCTS:
      return {
        ...state,
        ...action.products.reduce((obj, product) => {
          obj[product.id] = product
          return obj
        }, {})

mweststrate

import produce from "immer"

const todos = [ /* 2 todo objects in here */ ]

const nextTodos = produce(todos, draft => {
    draft.push({ text: "learn immer", done: true })
    draft[1].done = true
})

// old state is unmodified

mweststrate

import produce from "immer"

const nextState = produce(currentState, draft => {
  // empty function
})

console.log(nextState === currentState) // true

mweststrate

import { recordPatches } from "mobx-state-tree"

const runningActions = new Map()

export function atomicAsyncPatch(call, next) {
    switch (call.type) {
        case "action":
            return atomic(call, next)
        case "process_spawn": {
            const recorder = recordPatches(call.tree)

mweststrate

import { getSnapshot } from 'mobx-state-tree' 

const task1 = Todo.create({ title: "Try MST!" })
task1.toggle()

console.dir(getSnapshot(task1))
// prints { title: "Try MST!" , finished: true }

mweststrate

import { types } from 'mobx-state-tree'

export const Todo = types.model(
  'Todo',
  {
    title: types.string,
    finished: false,
  },
  {
    toggle() {

mweststrate

/**
 Shitty implementation of tracked compatible local component state library powered by MobX
 
 Demo: https://jsfiddle.net/mweststrate/Ltmhe3rh/
 
 @example
 
 class Example extends Component {
  // initialize state.count with a value:
  @tracked count = 1000;