anchor.diff:                    path: '/edit',
                     enter: (_) => counters['article_123_edit_entered']++));
   
  -      router.route('').then((_) {
  +      return router.route('').then((_) {
           expect(counters, {
             'list_entered': 1, // default to list
             'article_123_entered': 0,
             'article_123_view_entered': 0,
             'article_123_edit_entered': 0
           });
  -        router.route('/articles').then((_) {
  +        return router.route('/articles').then((_) {
             expect(counters, {
               'list_entered': 2,
               'article_123_entered': 0,
               'article_123_view_entered': 0,
               'article_123_edit_entered': 0
             });
  -          router.route('/article/123').then((_) {
  +          return router.route('/article/123').then((_) {
               expect(counters, {
                 'list_entered': 2,
                 'article_123_entered': 1,
                 'article_123_view_entered': 1, // default to view
                 'article_123_edit_entered': 0
               });
  -            router.route('/article/123/view').then((_) {
  +            return router.route('/article/123/view').then((_) {
                 expect(counters, {
                   'list_entered': 2,
                   'article_123_entered': 1,
                   'article_123_view_entered': 2,
                   'article_123_edit_entered': 0
                 });
  -              router.route('/article/123/edit').then((_) {
  +              return router.route('/article/123/edit').then((_) {
                   expect(counters, {
                     'list_entered': 2,
                     'article_123_entered': 1,
  
positive.code:             'fooLeave': 0,
              'fooEnter': 1,
            });
            router.route('/123?foo=bar').then((_) {
              expect(counters, {
                'fooLeave': 0,
                'fooEnter': 1,
  
negative.code:             'fooLeave': 0,
              'fooEnter': 1,
            });
            return router.route('/123?foo=bar').then((_) {
              expect(counters, {
                'fooLeave': 1,
                'fooEnter': 2,
  