Assert_equal undefined local variable LRTHW ex52

Question

Hi I made it to the lase exercise os Learn Ruby The Hard Way, and I come at the wall...

Here is the test code:

def test_gothon_map()
    assert_equal(START.go('shoot!'), generic_death)
    assert_equal(START.go('dodge!'), generic_death)

    room = START.go("tell a joke")

    assert_equal(room, laser_weapon_armory)
end

And here is the code of the file it should test:

class Room

  attr_accessor :name, :description, :paths

  def initialize(name, description)
    @name = name
    @description = description
    @paths = {}
  end

  def ==(other)
    self.name==other.name&&self.description==other.description&&self.paths==other.paths
  end

  def go(direction)
    @paths[direction]
  end

  def add_paths(paths)
    @paths.update(paths)
    end

end

generic_death = Room.new("death", "You died.")

And when I try to launch the test file I get an error:

generic_death = Room.new("death", "You died.")

I tried to set the "generic_death = Room.new("death", "You died.")" in test_gothon_map method and it worked but the problem is that description of the next object is extremely long, so my questions are:

• why assertion doesn't not respond to defined object?
• can it be done different way then by putting whole object to testing method, since description of the next object is extremely long...

Answer 1

The nature of local variable is that they are, well, local. This means that they are not available outside the scope they were defined.

That's why ruby does not know what generic_death means in your test.

You can solve this in a couple of ways:

• define rooms as constants in the Room class:

  class Room
    # ...
  
    GENERIC_DEATH = Room.new("death", "You died.")
    LASER_WEAPON_ARMORY = Room.new(...)
  end
  
  def test_gothon_map()
    assert_equal(Room::START.go('shoot!'), Room::GENERIC_DEATH)
    assert_equal(Room::START.go('dodge!'), Room::GENERIC_DEATH)
  
    room = Room::START.go("tell a joke")
  
    assert_equal(room, Room::LASER_WEAPON_ARMORY)
  end
  

• assert the room by its name, or some other identifier:

  def test_gothon_map()
    assert_equal(START.go('shoot!').name, "death")
    assert_equal(START.go('dodge!').name, "death")
  
    room = START.go("tell a joke")
  
    assert_equal(room.name, "laser weapon armory")
  end