From: "Jesús Gabriel y Galán" <jgabrielygalan@...>
Date: 2010-06-11T01:30:24+09:00
Subject: Question about testing self.inherited

Hi,

I have a class that keeps track of its subclasses using the self.inherited hook:

module GameFramework
  class Game
    attr_accessor :event_handler
    @available_games = []

    class << self
      attr_reader :available_games
    end
		
    def self.inherited subclass
      @available_games << subclass
    end
  end
end

I want to test this class, but I have a problem testing both the case
when there are no classes inheriting from Game and the case where
there are. I made this naive approach:

class TestGame < MiniTest::Unit::TestCase	
	def test_available_games_is_empty
		assert_empty GameFramework::Game.available_games
	end
	
	def test_available_games_has_one
		Class.new(GameFramework::Game)
		assert_equal 1, GameFramework::Game.available_games.size
	end
end

When I run these tests, the second one fails, probably is running
before the other one, defining the class, I guess. Is there a good way
to test these cases that I'm not seeing? Is the above strategy a good
one to keep track of existing subclasses of the Game class? I am using
the available games to create a menu for the user to choose which game
to play.

Thanks,

Jesus.