How can I get user data into a javascript object?

I have the code below in my functions.php file. However, when I try to access the variable theUser in my custom.js file it comes back as undefined.

Functions.php:

function theme_scripts() {
     global $current_user;
     $current_user = wp_get_current_user();

     wp_enqueue_script( 'theme-script', get_stylesheet_directory_uri() . '/assets/js/custom.js', array( 'jquery' ), '', true );
     wp_localize_script( 'theme-script', 'theUser', array (
        'username' = $current_user,
     ) );
  }
  add_action( 'wp_enqueue_scripts', 'theme_scripts' );

Custom.js:

var theUser;
var userName = theUser.username.data.display_name;
var userEmail = theUser.username.data.user_email;
console.log(theUser);