class FooTest < Test::Unit::TestCase
  include PresenceAssertions

  # The options required to get a valid Foo.
  @valid_options = { :name => 'qux', :other => 'bar' }

  def test_should_require_name
    assert_presence_of 'Foo', :name
  end
end


module PresenceAssertions
  def assert_presence_of(klass, attribute)
    obj = create_valid(klass, attribute => nil)
    assert_equal false, obj.valid?
  end

  def create_valid(klass, options)
    Object.const_get(klass).create(@valid_options.merge(options))
  end
end