gistfile1.rb

# The macro

class Test::Unit::TestCase  
  def self.should_be_in_state(state)
    klass = self.name.gsub(/Test$/, '').constantize
    context "#{klass}" do
      should "be #{state}" do
        assert_equal klass.new.state_name.to_s, state.to_s
      end
    end
  end
end

# my model, using a simple state machine plugin, like this one: http://github.com/pluginaweek/state_machine

class Post < ActiveRecord::Base
  state_machine :state, :initial => :active do
    state [:active, :inactive]
  end
end

# the test

require 'test_helper'

class PostTest < ActiveSupport::TestCase
  should_be_in_state :active
end