duck.js

import { call, put, takeLatest } from 'redux-saga/effects'
import client from '../httpClient'

const createAction = (type) => (payload) => ({
  type,
  payload,
})

const http = {
  login: (credentials) => client.post('/login', credentials),
}

const LOGIN = 'LOGIN'
const LOGIN_SUCCESS = 'LOGIN_SUCCESS'
const LOGIN_ERROR = 'LOGIN_ERROR'

const actions = {
  login: createAction(LOGIN),
  loginSuccess: createAction(LOGIN_SUCCESS),
  loginError: createAction(LOGIN_ERROR),
}

function* loginSaga(action) {
  try {
    const user = yield call(http.login, action.payload)
    yield put(actions.loginSuccess(user))
  } catch (e) {
    yield put(actions.loginError('Uh oh'))
  }
}

export function* authSagas() {
  yield takeLatest(LOGIN, loginSaga)
}

const initialState = {
  isLoading: false,
}

export default function reducer(state, action) {
  switch (action.type) {
    case LOGIN:
      return { ...state, isLoading: true }
    case LOGIN_SUCCESS:
      return { ...state, user: action.payload }
    case LOGIN_ERROR:
      return { ...state, isLoading: false }
  }
  return state
}