test_queue.rb

require 'test/unit'
require './queue'

class TestQueue < Test::Unit::TestCase
  def setup
    @q = Queue.new
  end

  def test_should_create_a_new_queue
    assert @q
  end

  def test_should_create_empty_queue
    assert_equal 0, @q.size
  end

  def test_should_add_a_node
    @q.push("random object")
    assert_equal 1, @q.size
  end

  def test_should_add_two_nodes
    @q.push("random object")
    @q.push("another random object")
    assert_equal 2, @q.size
  end

  def test_should_add_random_bunch_of_nodes
    i = Random.rand(1000)
    i.times { @q.push(i.to_s) }
    assert_equal i, @q.size
    i.times { assert_equal i.to_s, @q.pop }
  end

  def test_should_return_a_node
    @q.push("random object")
    o = @q.pop
    assert_equal "random object", o
  end

  def test_should_return_a_random_object
    t = Time.now
    @q.push(t)
    o = @q.pop
    assert_equal t, o
  end

  def test_should_shrink_after_pop
    @q.push("random object")
    o = @q.pop
    assert_equal 0, @q.size
  end

  def test_should_raise_exception_after_empty_pop
    exception = assert_raise(EmptyQueueError) { @q.pop }
    assert_equal "Empty queue", exception.message
  end

  def test_should_still_work_after_empty_pop
    begin
      @q.pop
    rescue EmptyQueueError
      @q.push("Another random string")
      assert_equal 1, @q.size
    end
  end
end