By interactive tutorial I mean, tutorials that contain unit tests for the tasks that you are supposed to achieve in that tutorial. One example is LearnYouNode. It is a tutorial series containing 13 problems that teach you Node.js

Each problems has fixed task(s) that you need to complete and there are unit tests in place to check whether you've completed the tutorial properly, there is no guessing work.

So, do you like such tutorials? Have you ever seen similar ones? I'd really like to know.