App.tsx

class App extends React.Component<any, any> {
  public render() {
    return (
      <Router>
        <Route path="/" component={HomePage}>
        </Route>
      </Router>
    );
  }
}

pages_Home.tsx

class HomePage extends React.Component<any, any> {
  public render() {
    return (
      <span>
        example. 
      </span>
    );
  }
}