getting error "Expected the reducer to be a function."? - reactjs

Question

I am getting error "Expected the reducer to be a function.".
I am trying to add redux in my project .I create reducer but also getting error "Expected the reducer to be a function." .here is my code
https://codesandbox.io/s/k5Gp2gglx
import React from 'react';
import { render } from 'react-dom';
import { createStore, applyMiddleware } from 'redux';
import thunk from 'redux-thunk';
import {Provider} from 'react-redux';
import {combindReducer} from './reducers/index'
import Hello from './Hello';
const styles = {
fontFamily: 'sans-serif',
textAlign: 'center',
};
const App = () => (
<div style={styles}>
<Hello name="CodeSandbox" />
<h2>Start editing to see some magic happen {'\u2728'}</h2>
</div>
);
const store = createStore(combindReducer,
applyMiddleware(thunk)
);
render(
<Provider store ={store}>
<App />
</Provider>
, document.getElementById('root'));
combine reducer
import {combineReducers } from 'redux';
import {first_redux} from './topstories';
const combindReducer = combineReducers({
item: first_redux
})
export default combindReducer;
topstories
export default function(state = [], action) {
switch (action.type) {
case 'ADD_ITEM':
return [
...state,
action.payload
];
case 'DELETE_ITEM':
const index = state.indexOf(action.payload);
if (index === -1) {
return state;
}
return state.slice(0, index).concat(state.slice(index + 1));
case 'UPDATE_ITEM':
let newList = state.slice()
newList.splice(action.payload.index, 1, action.payload.item)
return newList;
default:
return state
}
}

Answer 1

since you're using default exports (not named exports), the import statements for your reducers should not have curly braces:
import combindReducer from './reducers/index';
and
import first_redux from './topstories';
https://codesandbox.io/s/L8RE3X5D4