Ruby now can be unit test done on print method

How can be unit test done on the following printing method call get_list(). With assert_equal("["apple", "orange", "pear"]",@list.get_list()) result is nill

@list = ["apple", "orange", "pear"] 

def get_list()
   i = 0
   while (i < list.size())
      puts list[i]
      i = i + 1
   end
end 

Please can somebody give me tip please