Testing on rubyonrails

Hi
I am very new to Ruby on Rails, now i am working in Testing the Ruby on
Rails platform.I need to know what are the Tools available for
functional,unit,perfomance and automated testing tools? If you find
anything kindly let me know.actually i have got some of the tools such
as Selenium ,Watir and Mocha but i couldn’t understand that.i have tried
Rails External Tools wizard in RadRails but that is also making some
error.

By

Vijay