def test_all_execute_when_no_errors_are_thrown(self):
# Setup command chain with mocked __do__ functions
c2 = Command()
c1 = Command(next=c2)
c1.__do__ = Mock()
c2.__do__ = Mock()
# Action
c1.run()
# Assert all functions called
c1.__do__.assert_called_once()
c2.__do__.assert_called_once()
def test_chained_command_does_not_execute_if_parent_throws_exception(self):
# Assemble command chain with mocked __do__ functions
# Initial command triggered will throw exception
c1 = Command()
c2 = Command(previous=c1)
c1.__do__ = Mock(side_effect=Exception('Oh No!'))
c2.__do__ = Mock()
# Action
c1.run()
# Assert command one was called (Threw an exception) and c2 was not called
c1.__do__.assert_called_once()
c2.__do__.assert_not_called()
def test_set_action_overrides_with_lambda(self):
# Assemble
c1 = Command()
# Action
c1.set_action(lambda x, y: x + y)
# Assert
self.assertEqual(3, c1.__do__(1, 2))
def test_set_action_overrides_with_function(self):
c1 = Command()
def my_action(): return 1
c1.set_action(my_action)
self.assertEqual(1, c1.__do__())
def test_set_action_overrides_with_function_and_allows_params(self):
# Assemble
c1 = Command()
def my_action(x, y): return x + y
# Action
c1.set_action(my_action)
# Assert
self.assertEqual(3, c1.__do__(1, 2))
def test_child_command_rolls_back_self_on_exception(self):
# Assemble command chain with mocked __do__ functions
# Initial command triggered will throw exception
c1 = Command()
c2 = Command(previous=c1)
c2.__do__ = Mock(side_effect=Exception('Oh No!'))
c2.__undo__ = Mock()
# Action
c1.run()
# Assert command 2 was rolled back
c2.__undo__.assert_called_once()