How to test controller class in MVC?

I'm building a simple ios app in swift according to the model-view-controller structure. I can test the model class but giving it input data and assert the output result against my expectation. But I was wondering how could I test the controller class? It seems that if I do want to test the controller class, the testing logic would be much more complicated. Is there a standard way of testing controller class? Thanks in advance for any help!