class StateTestCase(TestCase):
def setUp(self) -> None:
self.state = State(Invoice.objects.create(status='draft'), 'status')
def test_hash_remains_the_same(self):
self.assertEqual(self.state._get_hash(), self.state._get_hash())
def test_get_db_state(self):
self.assertEqual(self.state.get_db_state(), 'draft')
def test_lock(self):
self.assertFalse(self.state.is_locked())
self.state.lock()
self.assertTrue(self.state.is_locked())
# nothing should happen
self.state.lock()
self.assertTrue(self.state.is_locked())
self.state.unlock()
self.assertFalse(self.state.is_locked())
def test_set_state(self):
self.state.set_state('void')
self.assertEqual(self.state.instance.status, 'void')
# make sure it was saved to db
self.state.instance.refresh_from_db()
self.assertEqual(self.state.instance.status, 'void')
def complete_transition(self, state: State, **kwargs):
"""
It completes the transition process for provided state.
The instance will be unlocked and callbacks executed
:param state: State object
"""
state.set_state(self.target)
logging.info(f'{state.instance_key} state changed to {self.target}')
state.unlock()
logging.info(f'{state.instance_key} has been unlocked')
self.callbacks.execute(state, **kwargs)
def fail_transition(self, state: State, exception: Exception, **kwargs):
"""
It triggers fail transition in case of any failure during the side effects execution.
:param state: State object
:param exception: Exception that caused transition failure
"""
if self.failed_state:
state.set_state(self.failed_state)
logging.info(
f'{state.instance_key} state changed to {self.failed_state}')
state.unlock()
logging.info(f'{state.instance_key} has been unlocked')
self.failure_callbacks.execute(state, exception=exception, **kwargs)
def change_state(self, state: State, **kwargs):
"""
This method changes a state by the following algorithm:
- Lock state
- Change state to `in progress` if such exists
- Run side effects which should run `complete_transition` in case of success
or `fail_transition` in case of failure.
:param state: State object
"""
if state.is_locked():
logging.info(f'{state.instance_key} is locked')
raise TransitionNotAllowed("State is locked")
state.lock()
logging.info(f'{state.instance_key} has been locked')
if self.in_progress_state:
state.set_state(self.in_progress_state)
logging.info(
f'{state.instance_key} state changed to {self.in_progress_state}'
)
self.side_effects.execute(state, **kwargs)
