aigoncharov

const createReducer = (initialState, reducerMap) => (
  state = initialState,
  action,
) => {
  // Pick a reducer from the object by key
  const reducer = state[action.type]
  if (!reducer) {
    return state
  }
  // Run the reducer if present

aigoncharov

const createReducer = (initialState, reducerMap) => (
  state = initialState,
  action,
) => {
  // Pick a reducer from the object by key
  const reducer = reducerMap[action.type]
  if (!reducer) {
    return state
  }
  // Run the reducer if present

aigoncharov

const makeSelectorCatNames = () =>
  createSelector(
    (state) => state.cats.data,
    (cats) => cats.data.reduce((accum, { name }) => `${accum} ${name}`, ''),
  )

aigoncharov

const selectorCatsData = (state) => state.cats.data
const selectorCatsLoading = (state) => state.cats.loading

aigoncharov

const makeSelectorCatsData = () =>
  createSelector(
    (state) => state.cats.data,
    (cats) => cats,
  )
const makeSelectorCatsLoading = () =>
  createSelector(
    (state) => state.cats.loading,
    (loading) => loading,
  )

aigoncharov

import { createSelector } from 'reselect'

const actionTypeCatsGetInit = 'CATS_GET_INIT'
const actionTypeCatsGetSuccess = 'CATS_GET_SUCCESS'
const actionTypeCatsGetError = 'CATS_GET_ERROR'

const actionCatsGetInit = () => ({ type: actionTypeCatsGetInit })
const actionCatsGetSuccess = (payload) => ({ type: actionTypeCatsGetSuccess, payload })
const actionCatsGetError = (error) => ({ type: actionTypeCatsGetError, payload: error })

aigoncharov

class CatsGetInit extends ActionStandard {}
class CatsGetSuccess extends ActionStandard {}
class CatsGetError extends ActionStandard {}

const reducerCatsLoading = createReducer(
  false,
  reducerLoadingMap(CatsGetInit, CatsGetSuccess, CatsGetError),
)
const reducerCatsData = createReducer(undefined, {
  [CatsGetSuccess.type]: () => action.payload,

aigoncharov

const catsGetAsync = async (dispatch) => {
  dispatch(new CatsGetInit())
  try {
    const res = await fetch('https://cats.com/api/v1/cats')
    const body = await res.json()
    dispatch(new CatsGetSuccess(body))
  } catch (error) {
    dispatch(new CatsGetError(error))
    dispatch(new GlobalErrorInit(error))
  }

aigoncharov

class GlobalErrorInit extends ActionStandard {}
class GlobalErrorClear extends ActionStandard {}

const reducerError = createReducer(undefined, {
  [GlobalErrorInit.type]: (state, action) => action.payload,
  [GlobalErrorClear.type]: (state, action) => undefined,
})

aigoncharov

class ActionStandard {
  get static type () {
    return `prefix/${this.name}`
  }
  constructor(payload) {
    this.type = this.constructor.type
    this.payload = payload
    this.error = payload instanceof Error
  }
}