react-router v4でのonEnter代替

react-route-v4-onenter.js

import React from 'react';
import { BrowserRouter as Router, Route, Switch, Redirect } from 'react-router-dom';

import App from 'components/app';
import Signup from 'components/signup';
import Signin from 'components/signin';
import Signout from 'components/signout';

const userOnly = (Component) => ({ history, match }) =>
  isAuthenticated() ? <Component history={history} match={match}/> : <Redirect to="/signin"/>;

const guestOnly = (Component) => ({ history, match }) =>
  isAuthenticated() ? <Redirect to="/"/> : <Component history={history} match={match}/>;

export default () => {
  return (
    <Router>
      <Switch>
        <Route exact path="/signup" render={guestOnly(Signup)}/>
        <Route exact path="/signin" render={guestOnly(Signin)}/>
        <Route exact path="/signout" component={Signout}/>
        <Route path="/" render={userOnly(App)}/>
      </Switch>
    </Router>
  );
};