Testing html element in Chai

I am testing an angular project, and I first wrote the tests in Jasmine to test if an attribute of an html element exists or not like this:

 expect(ref_button.getAttribute('disabled')).toEqual(null);

Now I wanna try the same in Cucumber Chai.

Is there any Chai syntax to do teh same, to check for an attribute of an HTML eleemnt?? In its documentation seems taht not.