Capybara can get us part of the way there. It allows us to work with an API rather than manipulating the HTML directly, but what it provides isn't an application specific API. It gives us low-level API methods like find, fill_in, and click_button, but it doesn't provide us with high-level methods to do things like "sign in to the app" or "click the Dashboard item in the navigation bar".

Methods must be tested both via a Lemon unit test and as a QED demo. The Lemon unit tests are for testing a method in detail whereas the QED demos are for demonstrating usage.