I am using Steak and Capybara to do my integration tests. I also would like to test the serialization output (webservices using XML and JSON format) of my models. The problem is that JSON is only available by using a XML HTTP Request. So Capybara's visit method does not work. It also seems that I don't have access to xhr method in my acceptance tests (not sure why, because I require the normal spec_helper.rb in my acceptance_helper.rb).
How do you test web services? Using the xhr method (after requiring it somehow)? A special method with Capybara? Something else?
I also have some custom serialization (beside the normal my_object.to_xml). I guess it is better to do that in the model tests. Would you then still test the web service output of those custom serializations?