assert(): Only passes if the boolean expression isn't false or nil (for example, assert 2 == 1 will always fail).
require 'test/unit'
class String
def titleize
self.gsub(/\s(\w)/) { |letter| letter.upcase }.gsub(/^\w/) do |letter|
letter.upcase
end
end
end
def test_words
assert("Let's make a test fail!", "foo".titleize)
end