Towers of Hanoi in Ruby with tests

towers_of_hanoi.rb

class Peg
  attr_accessor :title, :rings

  def initialize(title: , rings: 0)
    @title = title
    @rings = Array(1..rings)
  end
end

def move(rings, from, destination, other)
    if rings == 1
      ring = from.rings.pop
      p "Move ring #{ring} from #{from.title} to #{destination.title}"
      destination.rings.push ring
    else
      move(rings-1, from, other, destination)
      move(1, from, destination, other)
      move(rings-1, other, destination, from)
    end
end

def towers_of_hanoi()
  p "Please enter the number of disks (#1 will be the biggest): "
  number_of_rings = gets().to_i
  from = Peg.new(title: :From, rings: number_of_rings)
  to = Peg.new(title: :To, rings: 0)
  via = Peg.new(title: :Via, rings: 0)
  move number_of_rings, from, to, via
end

towers_of_hanoi

require "test/unit"

class TestTowersOfHanoi < Test::Unit::TestCase
  def setup
    @peg = Peg.new(title: "A", rings: 3)
  end

  def test_peg_title
    assert_equal("A",@peg.title)
  end

  def test_peg_rings
    assert_equal(Array, @peg.rings.class)
    assert_equal(3, @peg.rings.size)
  end

  def test_moves_rings
    from = Peg.new(title: :From, rings: 5)
    to = Peg.new(title: :To, rings: 0)
    via = Peg.new(title: :Via, rings: 0)
    move 5, from, to, via
    assert_equal 0, from.rings.size
    assert_equal 0, via.rings.size
    assert_equal 5, to.rings.size
  end

  def test_runs_with_no_exceptions
    from = Peg.new(title: :From, rings: 5)
    to = Peg.new(title: :To, rings: 0)
    via = Peg.new(title: :Via, rings: 0)
    assert_nothing_raised do
      move 5, from, to, via
    end
  end

  def teardown
    @peg = nil
  end
end