A demonstration of loginReducer.

loginReducer.js

// Don't forget to check the complete code here ---> https://github.com/shubhnik/redux-react-navigation/tree/authFlow
const initialState = { isLoggedIn: false };

const loginReducer = (state = initialState, action) => {
  switch (action.type) {
    case "LOGIN":
      return { ...state, isLoggedIn: true };

    case "LOGOUT":
      return { ...state, isLoggedIn: false };

    default:
      return state;
  }
};

export default loginReducer;