As a rough way to automatically classify tests, you can look for tools like capybara, selenium or htmlunit for feature and mocking libraries for unit. Mind you

As a rough way to automatically classify tests, you can look for tools like capybara, selenium or htmlunit for feature and mocking libraries for unit. Mind you, there's as many taxonomies for tests as there are tests. To be honest I expect one way to classify them is by working backwards from coverage -- feature tests should have low volume but wide distribution across a codebase (perhaps that's another metric -- density?). Unit tests would be narrow but deep on a particular module.