QTP supports functional and regression testing. ruby/rails community has several answers to it.
- rails framework has a Test/Unit framework built into it. start writing. :)
- Test/Unit framework supports unit test (model), functional test (controller), integration test (application)
- use BDD layer for more focused application level, business driven regression tests. rspec or cucumber.
- use object level functional testing with Test/spec or shoulda framework
- use watir (watin, watij, ...) or webrat for user acceptance testing (web applications only)
never fail a business requirement again. tightly focused coding. test first environment. be agile. let the odyssey begin...
if the question actually means "can we test automatically whatever we develop in RoR then the answer would be YES" and if the question will RoR test itself whatever we write, then as a framework, this will be evaluating from the tehnology perspective but logicall it cannot.