Mocha

So my previous post talked about overriding delegation. Then I remembered, Mocha. An honest to goodness stubbing/mocking library. Rather obviously, when testing units, I really don't want to fiddle around with the interaction of objects in each and every instance.

So instead of my convoluted example of conditionally_overriding_delegation, I can do the following (but hey you may have already known this):

class AbstractUnit
  extend Forwardable
  def_delegate :foo, :name

  def has_name?
    !(name.nil? || name.blank?)
  end
end

class AbstractUnitTest < Test::Unit::TestCase
  def setup
     @object = AbstractUnit.new
  end

  # Perhaps a reasonable test for delegation?
  def test_should_delegate_name_to_foo
    assert_equal @object.name, @object.foo.name
  end

  def test_has_name_should_be_false_if_name_is_empty
    @object.stubs(:name).returns('')
    assert ! @object.has_name?
  end

  def test_has_name_should_be_false_if_name_is_nil
    @object.stubs(:name).returns(nil)
    assert ! @object.has_name?
  end

  def test_has_name_should_be_false_if_name_is_blank
    @object.stubs(:name).returns('hello world')
    assert @object.has_name?
  end

end

Even in this case, Mocha is rather useful, I don't have to worry about testing the coupling that occurs due to delegation, and can test the objects responsibilities. Of course, now its time to look more into Mocha's documentation. It looks like there is some rather amazing stuff that can be done.