Set

set.rb

require 'minitest/autorun'

class SetTest < MiniTest::Unit::TestCase
  def setup
    @set = Set.new
  end

  def test_size
    assert_equal 0, @set.size
    @set.add 42
    assert_equal 1, @set.size
  end

  def test_include?
    refute @set.include? 42
    @set.add 42
    assert @set.include? 42
  end

  def test_add
    @set.add 13
    @set.add 13
    assert_equal 1, @set.size
  end

  def test_to_a
    @set.add 1
    @set.add 4
    @set.add 2

    ary = @set.to_a

    assert_equal 3, ary.size
    assert ary.include? 1
    assert ary.include? 2
    assert ary.include? 4
  end
end

class Set
  include Enumerable

  def initialize
    @hash = {}
  end

  def size
    @hash.size
  end

  def add(obj)
    @hash[obj] = true
  end

  def include?(obj)
    @hash.include? obj
  end

  def each(&block)
    @hash.keys.each(&block)
  end
end

class SortedSetTest < SetTest
  def setup
    @set = SortedSet.new
  end

  def test_to_a
    super
    assert_equal [1, 2, 4], @set.to_a
  end
end

class SortedSet < Set
  def each(&block)
    @hash.keys.sort.each(&block)
  end
end