Disjoint unions not working with imported constants

[JavoByte]

Hi, I'm trying to use disjoint unions to check a redux reducer. I have a constants file where I export all my constants, like this:

export const USERS_LOAD = "USERS_LOAD";
export const USERS_LOADED = "USERS_LOADED";

The problem is, if I import this constants and define my type Action like this:

type Action =
  | { type: typeof USERS_LOADED, users: Array<{}>}
  | { type: typeof API_ERROR, error: ?any}
  | { type: typeof USERS_LOAD };

And use it un my code like this:

function users(state: State = {
  loading: false,
  all: [],
}, action: Action): State {
  switch (action.type) {
    case USERS_LOAD :
      return {
        ...state,
        loading: true,
      };
    case USERS_LOADED :
      return {
        loading: false,
        all: action.users.map(user => new User(user)),
        error: null,
      };
    default :
      return state;
  }
}

I get the error in USERS_LOADED case: Property not found in action

However, if I define the constants directly in the file instead of importing them, the error goes away and works like expected

[agentcooper]

typeof USERS_LOAD is string and not literal 'USERS_LOAD': example. See also: #2639.

[JavoByte]

You're right. I changed that because without typeof I get the error

Ineligible value used in/as type annotation (did you forget 'typeof'?)

So, the real question is? Can I use the disjoint types with constants like I said, or it must be using literals?

[0rvar]

#4175