#!/usr/bin/python3.8
#
# Copyright 2020 The Fuchsia Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

import unittest

from typing import List

import util


class TestUtil(unittest.TestCase):

    def test_exponential_backoff(self) -> None:
        clock = util.FakeClock()
        backoff = util.ExponentialBackoff(
            clock, min_poll_seconds=1., max_poll_seconds=10., backoff=2.)
        backoff.wait()
        backoff.wait()
        backoff.wait()
        backoff.wait()
        backoff.wait()
        backoff.wait()
        self.assertEqual(clock.pauses, [1., 2., 4., 8., 10., 10.])


if __name__ == '__main__':
    unittest.main()