def test_all_attempts_edge(self):
backoff = Backoff()
assert backoff.max_attempts == Backoff.max_attempts
assert len(backoff.deltas) == 16
for edge in [-1, 0, 15, 16, 17]:
assert backoff.delta(edge) >= backoff.zero
assert backoff.remaining(edge, datetime.utcnow()) >= backoff.zero
if edge > 0:
assert backoff.expires(edge,
datetime.utcnow()) >= datetime.utcnow()
assert backoff.expired(edge, datetime.utcnow()) == False
else:
assert backoff.expires(edge,
datetime.utcnow()) <= datetime.utcnow()
assert backoff.expired(edge, datetime.utcnow())
def test_expires(self):
backoff = Backoff()
for attempt in range(backoff.max_attempts):
now = datetime.utcnow()
if attempt == 0:
assert backoff.expires(attempt, now) < datetime.utcnow()
continue
expect_delta = timedelta(seconds=2**attempt)
assert backoff.expires(attempt, now) > datetime.utcnow()
assert backoff.expires(attempt,
now - expect_delta) < datetime.utcnow()
assert backoff.expires(attempt, now -
(expect_delta * 2)) < datetime.utcnow()
assert backoff.expires(attempt,
now + expect_delta) > datetime.utcnow()
assert backoff.expires(attempt, now +
(expect_delta * 2)) > datetime.utcnow()
def test_expires_overflow(self):
backoff = Backoff()
assert backoff.expires(15, datetime.max) == datetime.max
assert backoff.expires(16, datetime.max) == datetime.max