问为何onEnter不在React-Router中调用？

// Authentication "before" filter
function requireAuth(nextState, replace){
  console.log("called"); // => Is not triggered at all 
  if (!isLoggedIn()) {
    replace({
      pathname: '/front'
    })
  }
}

// Render the app
render(
  <Provider store={store}>
      <Router history={history}>
        <App>
          <Switch>
            <Route path="/front" component={Front} />
            <Route path="/home" component={Home} onEnter={requireAuth} />
            <Route exact path="/" component={Home} onEnter={requireAuth} />
            <Route path="*" component={NoMatch} />
          </Switch>
        </App>
      </Router>
  </Provider>,
  document.getElementById("lf-app")