Zustand slices pattern with middleware ?

[Twiggeh]

I've looked at similar discussions, but I believe the person in question was using a custom middleware ?

I have tried creating a sliced store, but I did not manage to make it use Middleware correctly, I could also not find a recipe that could help me out.

Codesandbox

I have here an example store

const bearStore: StateCreator<
  AllStores,
  [
    ["zustand/subscribeWithSelector", never],
    ["zustand/persist", { fish: number }]
  ],
  [],
  BearStore
> = (set, get) => {
  return {
    addBear: (amount = 1) => set({ bears: get().bears + amount }),
    removeBear: (amount = 1) => set({ bears: get().bears - amount }),
    bears: 1
  };
};

that combines into an animalStore

const useAnimalStore = create<AllStores>()(
  persist(
    subscribeWithSelector((...a) => {
      return {
        ...bearStore(...a),
        ...fishStore(...a)
      };
    }),
    {
      name: "my store",
      partialize: (state) => {
        return { fish: [], addBear: 124123 };
      }
    }
  )
);

but partialize is not inferring the correct types, and I am getting strange errors on the ...a

I am not certain whether I am doing something wrong, or whether this is not a supported usecase

[dai-shi]

Here's what I've got:

https://tsplay.dev/NrD9VW

The key point seems this:

zustand/docs/guides/typescript.md

Line 405 in b1cea64

`YourPersistedState` is the type of state you are going to persist, ie the return type of `options.partialize`, if you're not passing `partialize` options the `YourPersistedState` becomes `Partial<YourState>`. Also [sometimes](https://github.com/pmndrs/zustand/issues/980#issuecomment-1162289836) passing actual `PersistedState` won't work. In those cases, try passing `unknown`.

Also #980 (comment) passing actual PersistedState won't work. In those cases, try passing unknown.

[mooalot]

I made zustand-namespaces to allow middleware to be used within slices.