require File.join(File.dirname(__FILE__), 'spartan_helper')
require 'active_test/asserts/difference'

class TestObject
  attr_accessor :id, :title, :count
  def initialize(count = 0)
    self.count = count
    self.title = "I am a Test Object"
  end
  def remove(amount = 1)
    self.count -= amount
  end
  def add(amount = 1)
    self.count += amount
  end
  def update_title
    self.title.reverse!
  end
  def self.count
    ObjectSpace.each_object(TestObject) { }
  end
end

class AssertsDifferenceTest < Test::Unit::TestCase
  
  include ActiveTest::Asserts::Difference

  def setup
    @object = TestObject.new
  end

  def test_should_assert_difference_of_one
    assert_difference TestObject, :count do
      TestObject.new
    end
  end

  def test_should_assert_no_difference
    assert_no_difference @object, :count do end
  end

  def test_should_assert_difference_greater_than_one
    assert_difference @object, :count, 1068 do
      @object.add 1068
    end
  end
  def test_should_assert_difference_on_floats
    assert_difference @object, :count, 0.5 do
      @object.add 0.5
    end
  end
  def test_should_assert_negative_difference_of_one
    assert_difference @object, :count, -1 do
      @object.remove
    end
  end
  
  def test_should_assert_change_in_return_value
    assert_change @object, :title do
      @object.update_title
    end
  end
  
  def test_should_assert_change_with_duping
    assert_change @object, :title do
      @object.title = "jimminy cricket"
    end
  end

  def test_should_assert_no_change
    assert_no_change @object, :count do
      @object.update_title
    end
  end

end