Can Redux manage just a boolean?

Question

I have a piece of state in my React & Redux App dealing with authentication. It's a boolean.

I'd like to simplify grabbing this piece of state from the Redux store but can't find examples of this.

Is this approach a bad idea? I know that mutating state is not the correct approach. I'm not sure if this constitutes a mutation though.

import {
  AUTHENTICATED,  
  AUTHENTICATION_ERROR,
  AUTHENTICATION_REMOVE,
  UNAUTHENTICATED,
} from '../actions/types';

let INITIAL_STATE = false

export default function( state = INITIAL_STATE, action) {
  switch(action.type) {
    case AUTHENTICATED:
      return !state

    case UNAUTHENTICATED:
      return state

    case AUTHENTICATION_ERROR:
      return state

    case AUTHENTICATION_REMOVE:
      return !state

    default:
      return state;
  }
}

If you're authenticated and in some way manages to authenticate again, you're not authenticated? — JLe, May 18 '18 at 06:55
I guess this would be one edge case. However I was reading about design patterns recently and I really do believe in this saying right here. https://imgur.com/a/tOxt9JX — PrimeTimeTran, May 18 '18 at 07:02

score 1 · Answer 1 · answered May 18 '18 at 06:55

This is perfectly fine. Because you are not mutating anything from the state.

Yes, You are not mutating the state. Because your state is just a boolean value and you are returning the opposite value of your state. But you are not making any change to the state.

const value = true;
console.log(!value) // This will not change the value directly but it just returns false

But try to use a key in the state. In future, if you want to add some more keys. You don't have to do so many changes.

score 1 · Answer 2 · answered May 18 '18 at 06:56

When your state is just a boolean, you aren't actually mutating the state by writing !state, since boolean, string and number values are immutable.

Also it might not be a bad idea to store just a boolean in the reducer state. However you must read You Might not need Redux to undestand more on when you should and should not use redux

score 0 · Answer 3 · answered May 18 '18 at 09:29

You can try this enhancer redux-named-reducers

Then your reducer is simplified to something like this:

authModule.reduce(AUTHENTICATED, { isAuthenticated: true })
authModule.reduce([UNAUTHENTICATED, AUTHENTICATION_ERROR, 
AUTHENTICATION_REMOVE], { isAuthenticated: false })

Then you can access authentication state from anywhere like this:

getState(authModule.isAuthenticated)

I'm being very strict with the authentication state here to be set only when authenticated, and unset for everything else, but you can adjust as you see fit.

Can Redux manage just a boolean?

3 Answers3