title: Rspec: stub out controller action
body: <p>I'm writing request specs for one controller and I'd like to stub out another controller's method which is called via AJAX. The controller action in the AJAX call is for geolocating addresses, and its unrelated to the rest of the request. The controller action always renders nothing.</p>
  
  <p>I've tried:</p>
  
  <pre><code>before :each
    AddressesController.any_instance.stub(:update).and_return nil
  end
  </code></pre>
  
  <p>However, that gives me an error:</p>
  
  <pre><code>Failure/Error: Unable to find matching line from backtrace
   ActionView::MissingTemplate:
     Missing template addresses/update, application/update
  </code></pre>
  
  <p>No view template exists for the action, since it always renders nothing.</p>
  
  <p>Is there a way I can stub out the other controller's action entirely, or do I need to stub out the internals of the method instead?</p>