test_change_expectation.rb

require File.dirname(__FILE__) + '/test_helper.rb'

class TestChangeExpectations < Test::Unit::TestCase
  def test_change
    var = 1
    lambda {var += 1}.should change {var}
  end
  
  def test_change_fails
    var = 1
    lambda do
      lambda { }.should change {var} 
    end.should raise_error
  end
  
  def test_change_by
    var = 1
    lambda {var += 1}.should change {var}.by(1)
  end
  
  def test_change_by_fails
    var = 1
    lambda do
      lambda {var += 2}.should change {var}.by(1) 
    end.should raise_error
  end
  
  def test_change_by_at_least
    var = 1
    lambda {var += 1}.should change {var}.by_at_least(1)
  end
  
  def test_change_by_at_least_fails
    var = 1
    lambda do
      lambda {var += 0.9}.should change {var}.by_at_least(1)
    end.should raise_error
  end
  
  def test_change_by_at_most
    var = 1
    lambda {var += 1}.should change {var}.by_at_most(1)
  end
  
  def test_change_by_at_most_fails
    var = 1
    lambda do
      lambda {var += 1.1}.should change {var}.by_at_most(1)
    end.should raise_error
  end
  
  def test_change_from_to
    var = 1
    lambda {var += 1}.should change {var}.from(1).to(2)
  end
  
  def test_change_from_to_fails
    var = 1
    lambda do
      lambda {var += 1.1}.should change {var}.from(1).to(2)
    end.should raise_error
  end
end