Autotest: friend or foe

For all of you who don't know what autotest is, it's just a ruby gem that lets you run your tests automatically in the background every time you make a change either in your code or in your tests. It is very clever, and a lot of people use it. You can see some examples in almost every screencast of a kata written in ruby.

Why I don't like autotest
Well, it's not that I don't like it. It is a very cool project and I've used it sometimes while performing a kata. My real problem with it is that it breaks the TDD cycle. Let me explain myself.

Running the test should be a blocking step
When we are doing TDD, we run the tests to get feedback. Then, we use that feedback to guide our code/design.
When we use autotest we are not waiting for the tests to fail, we just continue coding, ruining the TDD cycle.

Wait a second, I do not write any code till autotest tells me that there is a failing test.
Well done. Why are you using autotest then?

Update: Talking with Tom Brand the other day, he said that maybe it is ok to use autotest in the refactoring phase. I think he is right :)