test(ngOptions): ignore comments within a <select> element

ngOptions should ignore comments within a `<select>`element and keep only the `<!-- ngIf -->` comment of the empty option.

Ref #15812

Author: pbr1111

test/ng/directive/ngOptionsSpec.js

@@ -2641,6 +2641,23 @@ describe('ngOptions', function() {
       dealoc(element);
     }));
 
+
+    it('should ignore the comments within the select', function() {
+      scope.values = [
+        {name:'black'},
+        {name:'white'},
+        {name:'red'}
+      ];
+      scope.isBlank = true;
+
+      createSingleSelect('<!-- test comment --><option ng-if="isBlank" value="">blank</option><!-- test comment 2 -->');
+      scope.$apply();
+
+      expect(element.find('option')[0].value).toBe('');
+      expect(element.find('option')[0].textContent).toBe('blank');
+      expect(element.find('option')[1].textContent).toBe('black');
+    });
+
   });