Scenario: create a new film unsuccessfullyThis test is short, readable, and easy to write. It doesn't test every possible validation failure, and it's not the only test I have. (In fact, I have some RSpec model tests that test the more esoteric URL validation rules.) However, it does test the model, view, and controller's handling of validation failures, and it even tests that they integrate with each other.
Given I am logged in as "admin"
And I am on the admin films page
When I follow "New film"
And I press "Create"
Then I should see "There were problems with the following fields:"
And I should see "Name can't be blank"
And I should see "Url name can't be blank"
And I should see "Sort name can't be blank"
And I should see "URL doesn't look like a valid RTMPE URL"
But I should not see "Trailer URL doesn't look like a valid RTMPE URL"
And I should not see "Scene URL doesn't look like a valid RTMPE URL"
Can you imagine trying to write the same tests by separately testing the model, view, and controller using RSpec? Now, imagine trying to use a separate test for each assertion. That's a lot of code for something so trivial--this ain't rocket science, guys! Finally, remember that when you test the things separately, there's nothing preventing the code from crashing when you put all the pieces together. (For instance, what happens if the controller and view each pass their RSpec tests, but they disagree on the spelling of one of the assigns?)
Is there benefit to testing things separately--absolutely. Is it worth it in this case--absolutely not. I think it's important to remember that at a certain level, our job is to implement features that work. Tests are a means to an end--they help us keep the code working. They don't really have any intrinsic value for the stakeholder. They only have the secondary value of keeping the code working when it is extended.
Just as there is engineering value in implementing features using less code (as long as it remains readable), there is also engineering value in implementing features using less testing code (as long as the tests continue to serve their purpose of preventing regressions).
My point is that Cucumber lets you test more using less effort.