class StateTest(unittest.TestCase):
"""with four states, there are 16 possible transitions, including
'transitioning' to the same state.
"""
def setUp(self):
self.stream = Stream(None, None)
def _invalid(self, initial_state, invalid_states):
for invalid_state in invalid_states:
with self.assertRaises(ValueError):
self.stream.state = initial_state
self.stream._advance_state_to(invalid_state)
def _valid(self, initial_state, valid_states):
for valid_state in valid_states:
self.stream.state = initial_state
self.stream._advance_state_to(valid_state)
def test_disconnected(self):
"can go from disconnected to connecting or disconnected"
self._valid(DISCONNECTED, (CONNECTING, ))
self._invalid(DISCONNECTED, (CONNECTED, FINISHED, DISCONNECTED))
def test_connected(self):
"from connected can transition to FINISHED only"
self._valid(CONNECTED, (FINISHED, ))
self._invalid(CONNECTED, (CONNECTING, DISCONNECTED, CONNECTED))
def test_connecting(self):
"from connecting can transition to disconnected, connected or backing off"
self._valid(CONNECTING, (CONNECTED, FINISHED))
self._invalid(CONNECTING, (CONNECTING, DISCONNECTED))
def test_finished(self):
"from finished, cannot advance"
self._invalid(FINISHED, (CONNECTED, CONNECTING, DISCONNECTED))
self._valid(FINISHED, (FINISHED, ))