require 'spec_helper'

describe Immutable::Deque do
  describe 'modification (using #push, #pop, #shift, and #unshift)' do
    it 'works when applied in many random combinations' do
      array = [1,2,3]
      deque = Immutable::Deque.new(array)
      1000.times do
        case [:push, :pop, :shift, :unshift].sample
        when :push
          value = rand(10000)
          array.push(value)
          deque = deque.push(value)
        when :pop
          array.pop
          deque = deque.pop
        when :shift
          array.shift
          deque = deque.shift
        when :unshift
          value = rand(10000)
          array.unshift(value)
          deque = deque.unshift(value)
        end

        deque.to_a.should eql(array)
        deque.size.should == array.size
        deque.first.should == array.first
        deque.last.should == array.last
      end
    end
  end
end