TypeError：无法读取未定义错误的属性“ getState”

如何解决TypeError：无法读取未定义错误的属性“ getState”

在尝试集成redux时，我一直收到此错误。我已经检查了我的商店并在控制台上登录了store.getState（）以确保，并在浏览器上返回正确的值（在下面的代码中index.js的第6行）。我之前也曾尝试在index.js中创建商店，但这没有用。我在下面附上我的代码。

index.js

import App from './App';
import * as serviceWorker from './serviceWorker';

import store from "./store/store";
import Provider from "react-redux/lib/components/Provider";

console.log(store.getState());
ReactDOM.render(
  <Provider store={store}>
        <React.StrictMode>
            <App/>
        </React.StrictMode>
  </Provider>,document.getElementById('root')
);

serviceWorker.unregister();

App.js

import React from 'react';
import './App.css';
import {BrowserRouter} from "react-router-dom";
import theme from "./config/theme";
import {ThemeProvider} from "@material-ui/core/styles";
import Mercury from './pages/Mercury';
import {Provider} from "react-redux";


const app =({store})=> {
    return (
       <BrowserRouter>
          <ThemeProvider theme={theme}>
              <Mercury/>
          </ThemeProvider>
       </BrowserRouter>
    );
}

export default app;

store.js

import NavigationReducer from './reducers/navigationReducer';
import {createStore} from "redux";

const store = createStore(NavigationReducer);

export default store;

navigationReducer.js

const initialState = {
    selectedPage : "home"
}

const reducer =(state=initialState,action)=>{
    return state
}

export default reducer;

我的项目依赖项是

{
    "@material-ui/core": "^4.11.0","@material-ui/icons": "^4.9.1","@testing-library/jest-dom": "^4.2.4","@testing-library/react": "^9.3.2","@testing-library/user-event": "^7.1.2","css-loader": "^4.2.1","react": "^16.13.1","react-dom": "^16.13.1","react-redux": "^7.2.1","react-router-dom": "^5.2.0","react-scripts": "3.4.1","redux": "^4.0.5","style-loader": "^1.2.1"
  }