React Redux Tutorials - 16 - Reducers

define the initial state a reducer function

src / redux / cake / cakeReducer.js

import {BUY_CAKE} from './cakeTypes';

const initialState = {
  numOfCakes: 10
};

const cakeReducer = (state = initialState, action) => {
  switch(action.type) {
    case BUY_CAKE: return {
      ...state,
      numOfCakes: state.numOfCakes - 1
    }
    default: return state
  }
};

export default cakeReducer