tests/test_cryptography_utils.py

# This file is dual licensed under the terms of the Apache License, Version
# 2.0, and the BSD License. See the LICENSE file in the root of this repository
# for complete details.

from __future__ import absolute_import, division, print_function

import pytest

from cryptography import utils


def test_int_from_bytes_bytearray():
    assert utils.int_from_bytes(bytearray(b"\x02\x10"), "big") == 528
    with pytest.raises(TypeError):
        utils.int_from_bytes(["list", "is", "not", "bytes"], "big")


class TestCachedProperty(object):
    def test_simple(self):
        accesses = []

        class T(object):
            @utils.cached_property
            def t(self):
                accesses.append(None)
                return 14

        assert T.t
        t = T()
        assert t.t == 14
        assert len(accesses) == 1
        assert t.t == 14
        assert len(accesses) == 1

        t = T()
        assert t.t == 14
        assert len(accesses) == 2
        assert t.t == 14
        assert len(accesses) == 2

    def test_set(self):
        accesses = []

        class T(object):
            @utils.cached_property
            def t(self):
                accesses.append(None)
                return 14

        t = T()
        with pytest.raises(AttributeError):
            t.t = None
        assert len(accesses) == 0
        assert t.t == 14
        assert len(accesses) == 1
        with pytest.raises(AttributeError):
            t.t = None
        assert len(accesses) == 1
        assert t.t == 14
        assert len(accesses) == 1


def test_bit_length():
    assert utils.bit_length(1) == 1
    assert utils.bit_length(11) == 4