def test_from_goal_invalid(self):
with pytest.raises(ValueError):
GroupMember.from_goal(Goal('fred', action=lambda: None))
def test_from_goal_valid(self):
def predicate(tgt):
return tgt == 42
goal = Goal('fred', action=lambda: None, group=Group('heathers', predicate))
self.assertEqual(GroupMember('heathers', 'fred', predicate), GroupMember.from_goal(goal))
