def test_execute_energyRequired_command_fails(self):
        """
        If there is energy required and the command fails to run, the energy
        should not be consumed.
        """
        e = self.friendlyEngine()

        # require some energy
        e.engine.energyRequirement.return_value = 2

        # make some energy
        world = World(MagicMock())

        actor = world.create('thing')
        yield Charge(actor['id']).execute(world)
        yield Charge(actor['id']).execute(world)
        self.assertEqual(len(actor['energy']), 2)

        # do the action and consume the energy
        action = MagicMock()
        action.subject.return_value = actor['id']

        # synchronous
        action.execute.side_effect = NotAllowed('foo')
        self.assertFailure(e.execute(world, action), NotAllowed)
        self.assertEqual(len(actor['energy']), 2, "Should not have consumed "
                         "the energy")

        # asynchronous
        action.execute.side_effect = None
        action.execute.return_value = defer.fail(NotAllowed('foo'))
        self.assertFailure(e.execute(world, action), NotAllowed)
        self.assertEqual(len(actor['energy']), 2, "Should not have consumed "
                         "the energy")

    def test_failIfNotOnBoard(self):
        """
        The following actions require a bot to be on the board.
        """
        world = World(MagicMock())
        rules = StandardRules()

        bot = world.create('bot')['id']

        actions = [
            action.Charge(bot),
            action.ShareEnergy(bot, 'foo', 2),
            action.ConsumeEnergy(bot, 2),
            action.Shoot(bot, 'foo', 1),
            action.Repair(bot, 'foo', 1),
            action.MakeTool(bot, 'foo', 'foo'),
            action.OpenPortal(bot, 'foo', 'foo'),
            action.AddLock(bot, 'foo'),
            action.BreakLock(bot, 'foo'),
            action.LookAt(bot, 'foo'),
        ]

        for a in actions:
            try:
                rules.isAllowed(world, a)
            except NotAllowed:
                pass
            else:
                self.fail("You must be on a square to do %r" % (a,))

    def test_execute_Deferred(self):
        """
        If a command returns a successful deferred, wait to emit.
        """
        engine = MagicMock()
        d = defer.Deferred()
        engine.execute.return_value = d
        
        world = World(MagicMock(), engine)
        world.emit = MagicMock()

        action = MagicMock()
        action.emitters.return_value = ['I did it']

        r = world.execute(action)
        self.assertEqual(r, d, "Should return the result of the execution")
        
        engine.execute.assert_called_once_with(world, action)
        self.assertEqual(world.emit.call_count, 0, "Should not have emitted "
                         "the ActionPerformed event yet, because it hasn't "
                         "finished")
        d.callback('foo')
        self.assertEqual(self.successResultOf(r), 'foo',
                         "Should return the result of execution")
        world.emit.assert_called_once_with(ActionPerformed(action), 'I did it')

 def test_receiverFor_same(self):
     """
     You should get the same function each time you ask for a receiver for
     the same object.
     """
     world = World(MagicMock())
     self.assertEqual(world.receiverFor('foo'), world.receiverFor('foo'))

    def test_destroy_disableSubscribers(self):
        """
        When an object is destroyed, things subscribed to its events will
        no longer receive events.
        """
        world = World(MagicMock())
        thing = world.create('foo')

        received = []
        world.receiveFor(thing['id'], received.append)

        emitted = []
        world.subscribeTo(thing['id'], emitted.append)

        receiver = world.receiverFor(thing['id'])
        emitter = world.emitterFor(thing['id'])

        world.destroy(thing['id'])
        received.pop()
        emitted.pop()

        receiver('foo')
        self.assertEqual(received, [])
        self.assertEqual(emitted, [])

        emitter('foo')
        self.assertEqual(received, [])
        self.assertEqual(emitted, [])

    def test_makeSecondTool(self):
        """
        If you make a tool from a different piece of ore, your existing tool
        is unequipped and the lifesource it was made from is reverted to ore.
        """
        world = World(MagicMock())
        ore1 = world.create('ore')
        ore2 = world.create('ore')

        bot = world.create('bot')
        MakeTool(bot['id'], ore1['id'], 'knife').execute(world)

        MakeTool(bot['id'], ore2['id'], 'butterfly net').execute(world)

        self.assertEqual(bot['tool'], 'butterfly net',
                         "Should equip the new tool")
        self.assertEqual(ore1['kind'], 'ore', "Should revert to ore")
        self.assertEqual(ore2['kind'], 'lifesource')

        # kill original
        world.setAttr(ore1['id'], 'hp', 0)

        self.assertEqual(bot['tool'], 'butterfly net', "should not change tool"
                         " when the original ore dies")
        self.assertEqual(ore2['kind'], 'lifesource')

    def test_execute(self):
        """
        Listing squares should return a list of all the things in the world
        which are squares.  It should include their coordinates and number of
        each kind of thing inside them.
        """
        world = World(MagicMock())
        s1 = world.create('square')['id']
        s2 = world.create('square')['id']
        world.setAttr(s2, 'coordinates', (0, 1))
        
        thing1 = world.create('thing')['id']
        Move(thing1, s2).execute(world)

        output = ListSquares(thing1).execute(world)
        self.assertIn({
            'id': s1,
            'kind': 'square',
            'coordinates': None,
            'contents': {},
        }, output)
        self.assertIn({
            'id': s2,
            'kind': 'square',
            'coordinates': (0, 1),
            'contents': {
                'thing': 1,
            }
        }, output)
        self.assertEqual(len(output), 2)

    def test_execute_energyRequired_succeed(self):
        """
        If energy is required and the actor has enough energy, do the action.
        """
        e = self.friendlyEngine()

        # require some energy
        e.engine.energyRequirement.return_value = 2

        # make some energy
        world = World(MagicMock())

        actor = world.create('thing')
        yield Charge(actor['id']).execute(world)
        yield Charge(actor['id']).execute(world)
        self.assertEqual(len(actor['energy']), 2)

        # do the action and consume the energy
        action = MagicMock()
        action.subject.return_value = actor['id']
        action.execute.return_value = 'foo'
        
        ret = yield e.execute(world, action)
        self.assertEqual(ret, 'foo', "Should have executed the action")
        self.assertEqual(len(actor['energy']), 0, "Should have consumed "
                         "the energy")

 def test_emit(self):
     """
     All emissions are sent to my event_receiver
     """
     ev = MagicMock()
     world = World(ev)
     world.emit('something', 'foo')
     ev.assert_called_once_with('something')

    def test_badPassword(self):
        auth = FileStoredPasswords(self.mktemp())
        world = World(MagicMock(), auth=auth)

        thing = world.create('thing')
        yield CreateTeam(thing['id'], 'teamA', 'password').execute(world)
        self.assertFailure(JoinTeam(thing['id'], 'teamA',
                           'not password').execute(world), BadPassword)

 def test_create_uniqueId(self):
     """
     The id of an object should be unique
     """
     world = World(MagicMock())
     o1 = world.create('foo')
     o2 = world.create('bar')
     self.assertNotEqual(o1['id'], o2['id'])

 def test_get(self):
     """
     You can get objects.
     """
     world = World(MagicMock())
     obj = world.create('foo')
     obj2 = world.get(obj['id'])
     self.assertEqual(obj, obj2)

    def test_invalidLocation(self):
        """
        It is an error to move to a non-entity.
        """
        world = World(MagicMock())
        thing = world.create('thing')['id']

        self.assertRaises(NotAllowed, Move(thing, 4).execute, world)

    def test_nowhere(self):
        """
        If you are nowhere, return an empty list.
        """
        world = World(MagicMock())
        thing = world.create('thing')

        self.assertEqual(Look(thing['id']).execute(world), [])

 def test_emit_toEngine(self):
     """
     All emissions are sent to the engine.
     """
     ev = MagicMock()
     engine = MagicMock()
     world = World(ev, engine)
     world.emit('foo', 'object_id')
     engine.worldEventReceived.assert_called_once_with(world, 'foo')

    def test_basic(self):
        """
        Should return information about the object.
        """
        world = World(MagicMock())
        thing = world.create('thing')

        r = LookAt(thing['id'], thing['id']).execute(world)
        self.assertEqual(r, world.get(thing['id']))

 def test_envelope(self):
     """
     You can read/write on the envelope of objects.
     """
     world = World(MagicMock())
     obj = MagicMock()
     env = world.envelope(obj)
     self.assertTrue(isinstance(env, dict))
     env['foo'] = 'bar'

    def test_onlyOre(self):
        """
        Only ore can be turned into tools.
        """
        world = World(MagicMock())
        ore = world.create('flower')
        bot = world.create('bot')

        self.assertRaises(NotAllowed,
            MakeTool(bot['id'], ore['id'], 'knife').execute, world)

    def test_open(self):
        """
        You can open a portal on from some ore.
        """
        world = World(MagicMock())
        ore = world.create('ore')
        bot = world.create('bot')
        OpenPortal(bot['id'], ore['id'], 'user').execute(world)

        self.assertEqual(ore['portal_user'], 'user', "Should set the portal "
                         "user to the id of the user that can use the portal")
        self.assertEqual(ore['kind'], 'portal')

    def test_stayAbove0(self):
        """
        You can't damage something below 0 by shooting.
        """
        world = World(MagicMock())
        thing = world.create('foo')
        target = world.create('foo')

        world.setAttr(target['id'], 'hp', 30)
        Shoot(thing['id'], target['id'], 500).execute(world)

        self.assertEqual(target['hp'], 0, "Should reduce the hitpoints to 0")