在减速器导致问题之后列出 Redux-Toolkit extraReducers（TS2322 错误）

Question

问题

我正在使用 Redux-Toolkit，但下面的代码有问题。当extraReducers省略时，我的代码工作正常。extraReducers当 后列出时reducers，我遇到错误（如下所示）。当前面extraReducers列出时，我的代码工作正常。我在这里缺少什么？ reducers

type Item = { id: string, name: string }

export const itemsAdapter = createEntityAdapter<Item>();
const initialState = itemsAdapter.getInitialState();

export const slice = createSlice({
  name: 'items',
  initialState,
  reducers: {  
    itemsAdded(state, action: PayloadAction<{ items: Item[] }>) {
      itemsAdapter.setAll(state, action.payload.items);
    }, 
  },
  extraReducers: (builder) => { /*  },,
});

错误信息

TS2322: Type '(state: WritableDraft<EntityState<Item>>, action: { payload: { items: Item[]; }; type: string; }) => void' is not assignable to type 'CaseReducer<WritableDraft<EntityState<Item>> | undefined, { payload: any; type: string; }> | CaseReducerWithPrepare<WritableDraft<EntityState<Item>> | undefined, PayloadAction<...>>'.
  Type '(state: WritableDraft<EntityState<Item>>, action: { payload: { items: Item[]; }; type: string; }) => void' is not assignable to type 'CaseReducer<WritableDraft<EntityState<Item>> | undefined, { payload: any; type: string; }>'.
    Types of parameters 'state' and 'state' are incompatible.
      Type 'WritableDraft<WritableDraft<EntityState<Item>>> | undefined' is not assignable to type 'WritableDraft<EntityState<Item>>'.
        Type 'undefined' is not assignable to type 'WritableDraft<EntityState<Item>>'.

Answer 1

我通过提供参数类型解决了这个问题builder。

extraReducers: (builder: ActionReducerMapBuilder<MyCustomState>) => {
  builder.addCase(myCaseReducer, (state, action) => { /* this is code */ });
}

这可以防止打字稿推断MyCustomState | undefined

看起来确实是一个错误，在我更新 redux-toolkit 之前这不是问题