require 'spec_helper'

describe Immutable::Set do
  describe '#first' do
    context 'on an empty set' do
      it 'returns nil' do
        S.empty.first.should be_nil
      end
    end

    context 'on a non-empty set' do
      it 'returns an arbitrary value from the set' do
        %w[A B C].include?(S['A', 'B', 'C'].first).should == true
      end
    end

    it 'returns nil if only member of set is nil' do
      S[nil].first.should be(nil)
    end

    it 'returns the first item yielded by #each' do
      10.times do
        set = S.new((rand(10)+1).times.collect { rand(10000 )})
        set.each { |item| break item }.should be(set.first)
      end
    end
  end
end