class StateMachineTest(PythonicTestCase):
def setUp(self):
self.state = StateMachine(initial_state='new')
def test_can_initialize_statemachine(self):
StateMachine(initial_state='foo')
# --- adding states ------------------------------------------------------
def test_can_add_states(self):
self.state.add('new', 'processed', 'process')
self.state.add('new', 'new', 'noop')
def test_raise_exception_if_duplicate_action_is_defined(self):
self.state.add('new', 'processed', 'process')
with assert_raises(StateMachineDefinitionError):
self.state.add('new', 'new', 'process')
# --- introspection ------------------------------------------------------
def test_can_ask_for_current_state(self):
state = StateMachine(initial_state='foo')
state.add('foo', 'foo', 'noop')
assert_equals('foo', state.state())
assert_false(state.is_impossible_state())
def test_no_state_if_initial_state_not_available(self):
state = StateMachine(initial_state='invalid')
assert_none(state.state())
assert_true(state.is_impossible_state())
def test_can_ask_for_all_known_actions(self):
self.state.add('new', 'new', 'noop')
self.state.add('new', 'processed', 'process')
self.state.add('processed', 'new', 'rework')
assert_equals(set(('noop', 'process', 'rework')),
self.state.known_actions())
def test_can_ask_for_all_currently_allowed_actions(self):
self.state.add('new', 'new', 'noop')
self.state.add('new', 'processed', 'process')
self.state.add('processed', 'new', 'rework')
assert_equals(set(('noop', 'process')), self.state.allowed_actions())
self.state.set_state('processed')
assert_equals(set(('rework', )), self.state.allowed_actions())
def test_can_ask_for_all_known_states(self):
assert_equals(set(), self.state.known_states())
self.state.add('new', 'processed', 'process')
self.state.add('processed', 'done', 'finalize')
assert_equals(set(('new', 'processed', 'done')),
self.state.known_states())
def test_can_ask_for_all_non_final_states(self):
assert_equals(set(), self.state.known_non_final_states())
self.state.add('new', 'processed', 'process')
self.state.add('processed', 'done', 'finalize')
assert_equals(set(('new', 'processed')),
self.state.known_non_final_states())
# --- handling states ----------------------------------------------------
def test_can_not_set_state_to_invalid_state(self):
with assert_raises(StateMachineError):
self.state.set_state('invalid')
# --- executing ----------------------------------------------------------
def test_can_execute_states(self):
self.state.add('new', 'processed', 'process')
self.state.execute('process')
assert_equals('processed', self.state.state())
def test_handler_is_called_for_state_transition(self):
self._transition = None
def handler(from_state, to_state, action_name):
self._transition = (from_state, to_state, action_name)
self.state.add('new', 'new', 'noop', handler)
self.state.execute('noop')
assert_equals('new', self.state.state())
assert_equals(('new', 'new', 'noop'), self._transition)
def test_raise_exception_for_invalid_action(self):
self.state.add('new', 'processed', 'process')
with assert_raises(StateMachineError):
self.state.execute('invalid')
self.state.add('processed', 'new', 'rework')
with assert_raises(StateMachineError):
self.state.execute('rework')
self.state.execute('process')
with assert_raises(StateMachineError):
self.state.execute('process')
self.state.execute('rework')
def test_raise_exception_if_in_impossible_state(self):
state = StateMachine(initial_state='invalid')
state.add('new', 'processed', 'process')
with assert_raises(StateMachineError):
self.state.execute('process')
def test_raise_exception_if_no_outgoing_transition_defined_when_executing(
self):
self.state.add('new', 'processed', 'process')
self.state.set_state('processed')
with assert_raises(StateMachineError):
self.state.execute('rework')
# --- transition with operations and conditions --------------------------
def test_can_add_transition_with_additional_operation(self):
self.state.add('new', 'processed', 'process', operations=('set_foo', ))
def test_can_tell_if_flag_is_set(self):
assert_false(self.state.is_set(None))
assert_false(self.state.is_set('foo'))
def test_transition_can_also_set_flags(self):
self.state.add('new', 'processed', 'process', operations=('set_foo', ))
assert_false(self.state.is_set('foo'))
self.state.execute('process')
assert_true(self.state.is_set('foo'))
def test_can_add_conditional_transition(self):
self.state.add('new',
'authenticated',
'authenticate',
condition='if_tls')
def test_allowed_actions_obeys_condition(self):
self.state.add('new', 'new', 'use_tls', operations=('set_tls', ))
self.state.add('new',
'authenticated',
'authenticate',
condition='if_tls')
assert_equals(set(('use_tls', )), self.state.allowed_actions())
self.state.execute('use_tls')
assert_equals(set(('use_tls', 'authenticate')),
self.state.allowed_actions())
def test_conditional_transition_is_only_executed_if_flag_is_true(self):
self.state.add('new', 'new', 'use_tls', operations=('set_tls', ))
self.state.add('new',
'authenticated',
'authenticate',
condition='if_tls')
assert_equals('new', self.state.state())
with assert_raises(StateMachineError):
self.state.execute('authenticate')
self.state.execute('use_tls')
assert_true(self.state.is_set('tls'))
self.state.execute('authenticate')
def test_can_also_specify_negative_flag_checks_for_transitions(self):
self.state.add('new',
'new',
'use_tls',
operations=('set_tls', ),
condition='if_not_tls')
self.state.add('new',
'authenticated',
'authenticate',
condition='if_tls')
with assert_raises(StateMachineError):
self.state.execute('authenticate')
self.state.execute('use_tls')
with assert_raises(StateMachineError):
self.state.execute('use_tls')
self.state.execute('authenticate')
def test_can_ask_for_current_state(self):
state = StateMachine(initial_state='foo')
state.add('foo', 'foo', 'noop')
assert_equals('foo', state.state())
assert_false(state.is_impossible_state())
def test_raise_exception_if_in_impossible_state(self):
state = StateMachine(initial_state='invalid')
state.add('new', 'processed', 'process')
with assert_raises(StateMachineError):
self.state.execute('process')