test_name_sticks.rb

require 'minitest/autorun'

class RobotTest < MiniTest::Unit::TestCase
  def test_name_sticks
    robot = Robot.new
    robot.name
    assert_equal robot.name, robot.name
  end
end

class Robot
  def initialize
    @name = ''
  end

  def name
    2.times {@name << ('A'..'Z').to_a.sample}
    3.times {@name << (0..9).to_a.sample.to_s}
    @name
  end

  def reset
    @name = ''
  end
end

# via exercism.io