Hiya! Something of a newbie, going through the Simply Rails 2 book and have encountered a problem whilst testing.

I've copied the test suite from the code archive (after being thrown the exact same error when typing it myself) and have been given this error message;

"functional/../test_helper.rb:22: undefined method 'use_transactional_fixtures=' for Test::Unit::TestCase:Class (NoMethodError)"

Anyone know what might be going on here? The app seems to work correctly, but I'm loathed to skip over too much testing.