def test_remaining(self):
backoff = Backoff()
for attempt in range(backoff.max_attempts):
now = datetime.utcnow()
if attempt == 0:
assert backoff.remaining(attempt, now) == timedelta()
continue
expect_delta = timedelta(seconds=2**attempt)
assert backoff.remaining(attempt, now) > timedelta()
assert backoff.remaining(attempt, now) < expect_delta
assert backoff.remaining(attempt,
now - expect_delta) == timedelta()
assert backoff.remaining(attempt,
now + expect_delta) > expect_delta
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())