test_helper.rb

# Generate generic tests for instance and unsaved objects
# object as String
# uniqueness_attr as Array
# model_generic_tests("account", %w(name))
def model_generic_tests(object, uniqueness_attr=[])
  context "A #{object} instance" do
    setup do
      @object = Factory(object.to_sym)
    end

    should "return its name" do
      assert @object.name
    end

    uniqueness_attr.each do |attr|
      model_uniqueness_tests(@object, attr)
    end
    
    should "not save #{object} without name" do
      @object.name = nil
      assert !@object.save
    end
  end
  context "A unsaved #{object} instance" do
    setup do
      @object = Factory.build(object.to_sym, :name => nil)
    end

    should "not save #{object} without name" do
      assert !@object.save
    end
  end
end

# Generate uniqueness_tests
# object as String
# attribute as String
# model_uniqueness_tests("account", "name")
def model_uniqueness_tests(object, attribute)
  should "have unique #{attribute}" do
    object = Factory(object.to_sym, attribute.to_sym => "unique")
    object_not_unique = Factory.build(object.to_sym, attribute.to_sym => "unique")

    assert !object_not_unique.save
  end
end