test_utils.py

# -*- coding: utf-8 -*-
#
# diffoscope: in-depth comparison of files, archives, and directories
#
# Copyright © 2015 Jérémy Bobbio <lunar@debian.org>
#
# diffoscope is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# diffoscope is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with diffoscope.  If not, see <https://www.gnu.org/licenses/>.

import codecs
import os
import pytest
import threading

from diffoscope.config import Config
from diffoscope.difference import Difference
from diffoscope.comparators.utils.command import Command

from ..utils.data import data, load_fixture
from ..utils.tools import (
    tools_missing,
    skip_unless_tools_exist,
    skip_unless_module_exists,
)


fuzzy_tar1 = load_fixture('fuzzy1.tar')
fuzzy_tar2 = load_fixture('fuzzy2.tar')
fuzzy_tar3 = load_fixture('fuzzy3.tar')


def test_tools_missing():
    assert tools_missing() is True
    assert tools_missing('/missing') is True
    for x in ['cat', 'sh']:
        assert tools_missing(x) is False


@skip_unless_tools_exist()
def test_skip_unless_tools_exist_empty():
    pytest.xfail("Test should always be skipped")


@skip_unless_tools_exist('/missing')
def test_skip_unless_tools_exist_missing():
    pytest.xfail("Test should always be skipped")


def skip_unless_tool_is_at_least():
    func = skip_unless_tool_is_at_least
    assert func('/missing', 1, 1).name is 'skip'
    # pytest.skipif().args[0] contains the evaluated statement
    assert func('cat', 1, 1).args[0] is False
    assert func('cat', 1, '1.2d.45+b8').args[0] is True

    def version():
        return '4.3-git'

    assert func('cat', version, '4.3').args[0] is False


@skip_unless_module_exists('tlsh')
def test_fuzzy_matching(fuzzy_tar1, fuzzy_tar2):
    differences = fuzzy_tar1.compare(fuzzy_tar2).details
    expected_diff = codecs.open(
        data('text_iso8859_expected_diff'), encoding='utf-8'
    ).read()
    assert differences[1].source1 == './matching'
    assert differences[1].source2 == './fuzzy'
    assert 'similar' in differences[1].comment
    assert differences[1].unified_diff == expected_diff


@skip_unless_module_exists('tlsh')
def test_fuzzy_matching_only_once(fuzzy_tar1, fuzzy_tar3):
    differences = fuzzy_tar1.compare(fuzzy_tar3).details
    assert len(differences) == 2


fuzzy_tar_in_tar1 = load_fixture('fuzzy-tar-in-tar1.tar')
fuzzy_tar_in_tar2 = load_fixture('fuzzy-tar-in-tar2.tar')


@skip_unless_module_exists('tlsh')
def test_no_fuzzy_matching(monkeypatch, fuzzy_tar_in_tar1, fuzzy_tar_in_tar2):
    monkeypatch.setattr(Config(), 'fuzzy_threshold', 0)
    difference = fuzzy_tar_in_tar1.compare(fuzzy_tar_in_tar2)
    assert len(difference.details) == 1
    assert difference.details[0].source1 == 'file list'


@skip_unless_module_exists('tlsh')
def test_no_fuzzy_matching_new_file(
    monkeypatch, fuzzy_tar_in_tar1, fuzzy_tar_in_tar2
):
    monkeypatch.setattr(Config(), 'fuzzy_threshold', 0)
    monkeypatch.setattr(Config(), 'new_file', True)
    difference = fuzzy_tar_in_tar1.compare(fuzzy_tar_in_tar2)
    assert len(difference.details) == 3
    assert difference.details[1].source2 == '/dev/null'
    assert difference.details[2].source1 == '/dev/null'


@skip_unless_tools_exist('tee')
def test_trim_stderr_in_command():
    class FillStderr(Command):
        def cmdline(self):
            return ['tee', '/dev/stderr']

        def stdin(self):
            r, w = os.pipe()
            r, w = os.fdopen(r), os.fdopen(w, "w")

            def write():
                for dummy in range(0, Command.MAX_STDERR_LINES + 1):
                    w.write('error {}\n'.format(self.path))

            threading.Thread(target=write).start()

            return r

    difference = Difference.from_command(FillStderr, 'dummy1', 'dummy2')
    assert '[ 1 lines ignored ]' in difference.comment