user

$attributes = [
  'title' => 'View user profile.',
];
$link = $test_user->toLink(NULL, 'canonical', ['attributes' => $attributes])->toString();

$user = \Drupal::routeMatch()->getParameter('user');

$current_user = \Drupal::currentUser();
$roles = $current_user->getRoles();
if (in_array('editor', $roles, TRUE)) {
  //
}