assert_respond_to [object], :[method] #does object method exist? ex. assert_respond_to "string", :lowercase
assert_equal [string, [method] #is first string equal to results of second method?
assert_match [regex], [method] #is first regex equal to second string?
assert_nil
assert_not_nil [method] #is method nil?
assert_raise(RuntimeError), [method]