Get the type of redux's state-CodePudding

I want to get a type for redux state, which will be used to mock said state.

So far I figured out I have this Reducer:

(alias) const reducer: {
    selectedElement: Reducer<StructureElement, AnyAction>;
    fetchedState: Reducer<FetchedState, AnyAction>;
    ... 10 more ...;
    mesApi: Reducer<...>;
}

So what I want to do, is somehow get the StructureElement, FetchedState and so on from inside of the Reducer</here/, AnyAction>; part.

How can I achieve that?

Or is there a better way to get combined state type? It has to be done automatically though. I don't want to change types in 2 places when it should be auto-generated.

If I try this:

type State = typeof reducer;

I get

Type '{ selectedElement: Reducer<StructureElement, AnyAction>; fetchedState: Reducer<FetchedState, AnyAction>; ... 10 more ...; mesApi: Reducer<...>; }' is not assignable to type '{ selectedElement?: { stateId: string; parentId: string; hasChild: boolean; pathList: string[]; name: string; color: string; isActive: boolean; level: number; children?: ...[]; key?: string; type: StateType; }; ... 11 more ...; mesApi?: { ...; }; }'. Types of property 'selectedElement' are incompatible.

which makes sense.

CodePudding user response：

I'd recommend to simply model it explicitly and then import those types where you need them:

export type UserState = {
    readonly isLoggedIn: boolean;
    // other user state here
};

// Type for entire global redux state
export type AppState = {
    users: UserState;
    // other sub-states here
};

CodePudding user response：

I personally create a slice for each feature that I want in my state, then I have a file in which I'll first declare and export my RootState Type, and then I'll combine all of my reducers.

export interface RootState {
  pokemon: pokemonState;
  pokemonTrainer: pokemonTrainerState;
}

const reducer = combineReducers<RootState>({
  pokemon: pokemonSLice,
  pokemonTrainer: pokemonTrainerSlice,
});

Where pokemonState and pokemonTrainerState are the types of each feature.
And then I'll use RootState wherever I need.