javascript - 具有输入值的函数的返回类型

Question

所以基本上我想为我的组合 reducer 渲染一个返回类型，我这样做就很好:

const rootReducer = combineReducers({
  notes: notesReducer,
  categories: categoriesReducer,
  flyout: flyoutReducer
  // more reducers
});

export type AppState = ReturnType<typeof rootReducer>;

但是，如果我接受函数传入的值，我就会遇到正确返回类型的问题。下面的例子:

const rootReducer = history =>
  combineReducers({
    router: connectRouter(history),
    page: pageReducer,
    ....
    ....

export type AppState = ReturnType<typeof rootReducer>;

如何调用该函数以获得相同的返回类型？

Answer 1

您只需使用 ReturnType 两次即可:

const rootReducer = history =>
    combineReducers({
        router: connectRouter(history),
        page: pageReducer,
    });

export type AppState = ReturnType<ReturnType<typeof rootReducer>>;

Playground Link