def test_can_transition(self):
sm = StateMachine()
sm.add(State('online', is_starting_state=True))
sm.add(State('offline'))
sm.add(State('error'))
sm.add(Transition('online', ['offline', 'error']))
assert sm.can_transition_to('offline')
assert sm.can_transition_to('error')
def test_cant_transition_without_starting_state(self):
sm = StateMachine()
sm.add(State('online'))
sm.add(State('offline'))
sm.add(State('error'))
sm.add(Transition('online', ['offline', 'error']))
with pytest.raises(Exception):
sm.can_transition_to('offline')
sm.can_transition_to('error')
def test_transitions_arent_two_way(self):
sm = StateMachine()
sm.add(State('online', is_starting_state=True))
sm.add(State('offline'))
sm.add(Transition('offline', ['online']))
assert not sm.can_transition_to('offline')
def test_cant_transition_where_cant_transition_to(self):
sm = StateMachine()
sm.add(State('online', is_starting_state=True))
sm.add(State('offline'))
sm.add(Transition('offline', ['online']))
assert not sm.can_transition_to('offline')
with pytest.raises(Exception):
sm.transition_to('offline')
def test_cant_transition_to_undefined_state(self):
sm = StateMachine()
with pytest.raises(Exception):
sm.can_transition_to('offline')
