错误 - 类型错误：使用 next.js 中的 redux 存储时无法读取未定义的属性（读取“getState”）

Question

Just came across this issue error - TypeError: Cannot read properties of undefined (reading 'getState') with next.js and redux.

Here is my code below, I don't know the reason why I am facing this issue.

pages/app/store.js

import { configureStore } from "@reduxjs/toolkit";
import counterSlice from "../slices/counterSlice";

export const store = configureStore({
    reducer: {
        counter : counterSlice
    }
});

pages/slices/counterSlicer.js

import { createSlice } from "@reduxjs/toolkit";

const initialState = {
    count : 0
};

export const counterSlice = createSlice({
    name : "counter",
    initialState,
    reducers: {
        increment : (state , action) => {
            state.count += 1;
        }
    }
});

export const { increment } = counterSlice.actions;

export const getCount = (state) => state.counter.count;

export default counterSlice.reducer;

I never had dispatched any action yet, maybe dispatch later

pages/_app.js

import '../styles/globals.css'
import { Provider } from 'react-redux';
import { store } from '@reduxjs/toolkit';

function MyApp({ Component, pageProps }) {
  return (
    <Provider store={store}>
      <Component {...pageProps} />
    </Provider>
  )
}

export default MyApp;

and finally in pages/index.js

import styles from '../styles/Home.module.css'
import { useSelector } from 'react-redux'
import { getCount } from './slices/counterSlice'

export default function Home() {
  const value = useSelector(getCount);
  return (
    <div className={styles.container}>
      The value is {value}
     </div>
  )
}

Note: For more info let me tell you that I have tried the exact code in react app also, but the same code is working in react but not working in next.js

You can check the output of react in this image

Answer 1

You need to wrap props.

Please see this https://github.com/kirill-konshin/next-redux-wrapper/blob/master/packages/demo-redux-toolkit/pages/_app.tsx

Export wrapper from your store.js

import { createWrapper } from 'next-redux-wrapper';
...
export const wrapper = createWrapper(makeStore);

And your _app.js should be

 import '../styles/globals.css' import { Provider } from 'react-redux'; import { wrapper } from './store'; function MyApp({ Component, ...rest }) { const { store, props } = wrapper.useWrappedStore(rest); return ( <Provider store={store}> <Component {...props} /> </Provider> ); } export default MyApp;