React-router: TypeError: Cannot set property 'props' of undefined

Question

I am trying to set up routing in Meteor using react-router package and have encountered the following TypeError:

Link to image: https://postimg.org/image/v0twphnc7/

The code in I use in main.js

import React from 'react';
import ReactDOM from 'react-dom';
import { Router, Route, IndexRoute, browserHistory } from 'react-router';

// Importing components
import App from './components/app';
import Portfolio from './components/portfolio/portfolio';


//Creating a route
const routes = (
  <Router history={browserHistory}>
    <Route path='/' component={App}>
      <Router path='portfolio' component={Portfolio} />
    </Route>
  </Router>
);


// Loading routes
Meteor.startup(() => {
  ReactDOM.render(routes, document.querySelector('.universe'));
});

The problem that I've managed to identify is that when I define portfolio as a Simple Component it works.

const Portfolio = () => {
    return (
        <div className='red'>Portfolio page</div>
    );
}

But when I extend it from the Component is where the error comes in:

class Portfolio extends Component () {
  render() {
    return (
        <div>Portfolio page</div>
    );
  }
}

Can you please explain the possible difference between "normal" and class component and why the following error appears.

Answer 1

Assuming you are importing Component as a React.Component correctly, try removing the parenthesis after Component.

Should be:

class Portfolio extends Component {

instead of:

class Portfolio extends Component () {

If not, replace Componentwith React.Component.