How to read cookie on server-side with Express?

On my client-side I'am saving a token in the user's cookies :

this.socket.on('server:authentication', function(tokenObject){
  if(tokenObject){
    sessionStorage.setItem("token", tokenObject);
    this.setState({ submitted: true});
  }
}.bind(this));

Then I want to read that token on the server side, but when I do :

app.use(cookieParser());

app.use(function(req, res, next){
    const { token } = req.cookies;
    console.log(token);
...
});

I get "undefined" on the console. Same thing when I try console.log(req.cookies.token). How can I achieve that?

via Mit