Algorithm to shuffle an Array randomly based on different weights

Question

I have a collection of elements that I want to shuffle randomly, but every element has a different priority or weight. So the element with bigger weight has to have more pro

Answer 1

I have my solution but I think it can be improved:

module Utils
  def self.random_suffle_with_weight(elements, &proc)
    # Create a consecutive chain of element
    # on which every element is represented
    # as many times as its weight.
    consecutive_chain = []
    elements.each do |element|
      proc.call(element).times { consecutive_chain << element }
    end

    # Choosine one element randomly from
    # the consecutive_chain and remove it for the next round
    # until all elements has been chosen.
    shorted_elements = []
    while(shorted_elements.length < elements.length)
      random_index = Kernel.rand(consecutive_chain.length)
      selected_element = consecutive_chain[random_index]
      shorted_elements << selected_element
      consecutive_chain.delete(selected_element)
    end

    shorted_elements
  end
end

Test:

def test_random_suffle_with_weight
  element_1 = { :id => "ID_1", :weight => 10 }
  element_2 = { :id => "ID_2", :weight => 20 }
  element_3 = { :id => "ID_3", :weight => 60 }
  elements = [element_1, element_2, element_3]

  Kernel.expects(:rand).with(90).returns(11)
  Kernel.expects(:rand).with(70).returns(1)
  Kernel.expects(:rand).with(60).returns(50)

  assert_equal([element_2, element_1, element_3], Utils.random_suffle_with_weight(elements) { |e| e[:weight] })
end