recursion.rb

require "test/unit"

def balanced?(string)
  # ...
end

def count_change(money, coins)
  # ...
end

class BalanceSuite < Test::Unit::TestCase
  def test_some_lisp
    assert balanced?("(if (zero? x) max (/ 1 x))")
  end

  def test_i_told_him
    assert balanced?("I told him (that it's not (yet) done).\n(But he wasn't listening)")
  end

  def test_smiley_is_unbalanced
    assert !balanced?(":-)")
  end

  def test_counting_is_not_enough
    assert !balanced?("())(")
  end
end

class CountChangeSuite < Test::Unit::TestCase
  def test_four_from_one_and_two
    assert count_change(4, [1, 2]) == 3
  end

  def test_sorted_swiss_francs
    assert count_change(300, [5, 10, 20, 50, 100, 200, 500]) == 1022
  end

  def test_unsorted_swiss_francs
    assert count_change(300, [500, 5, 50, 100, 20, 200, 10]) == 1022
  end

  def test_no_pennies
    assert count_change(301, [5, 10, 20, 50, 100, 200, 500]) == 0
  end
end