test_binary.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 os.path
import pytest
import subprocess

from os import mkdir, symlink
from tempfile import TemporaryDirectory

from diffoscope.tools import tool_required
from diffoscope.exc import RequiredToolNotFound
from diffoscope.difference import Difference
from diffoscope.comparators.binary import FilesystemFile
from diffoscope.comparators.utils.file import File
from diffoscope.comparators.missing_file import MissingFile
from diffoscope.comparators.utils.compare import Xxd

from ..utils.data import data, init_fixture, get_data, normalize_zeros
from ..utils.tools import skip_unless_tools_exist, skip_unless_module_exists


TEST_FILE1_PATH = data('binary1')
TEST_FILE2_PATH = data('binary2')
TEST_ASCII_PATH = data('text_ascii1')
TEST_UNICODE_PATH = data('text_unicode1')
TEST_ISO8859_PATH = data('text_iso8859')


binary1 = init_fixture(TEST_FILE1_PATH)
binary2 = init_fixture(TEST_FILE2_PATH)

def test_same_content(binary1):
    assert binary1.has_same_content_as(binary1) is True

def test_not_same_content(binary1, binary2):
    assert binary1.has_same_content_as(binary2) is False

def test_guess_file_type():
    assert File.guess_file_type(TEST_FILE1_PATH) == 'data'

def test_guess_encoding_binary():
    assert File.guess_encoding(TEST_FILE1_PATH) == 'binary'

def test_guess_encoding_ascii():
    assert File.guess_encoding(TEST_ASCII_PATH) == 'us-ascii'

def test_guess_encoding_unicode():
    assert File.guess_encoding(TEST_UNICODE_PATH) == 'utf-8'

def test_guess_encoding_iso8859():
    assert File.guess_encoding(TEST_ISO8859_PATH) == 'iso-8859-1'

def test_no_differences_with_xxd(binary1):
    difference = binary1.compare_bytes(binary1)
    assert difference is None

@skip_unless_tools_exist('xxd')
def test_compare_with_xxd(binary1, binary2):
    difference = binary1.compare_bytes(binary2)
    expected_diff = get_data('binary_expected_diff')
    assert normalize_zeros(difference.unified_diff) == expected_diff

def test_compare_non_existing_with_xxd(binary1):
    difference = binary1.compare_bytes(MissingFile('/nonexisting', binary1))
    assert difference.source2 == '/nonexisting'

@pytest.fixture
def xxd_not_found(monkeypatch):
    def mock_cmdline(self):
        raise RequiredToolNotFound('xxd')
    monkeypatch.setattr(Xxd, 'cmdline', mock_cmdline)

def test_no_differences_without_xxd(xxd_not_found, binary1):
    difference = binary1.compare_bytes(binary1)
    assert difference is None

def test_compare_without_xxd(xxd_not_found, binary1, binary2):
    difference = binary1.compare(binary2)
    expected_diff = get_data('binary_hexdump_expected_diff')
    assert difference.unified_diff == expected_diff

def test_with_compare_details():
    d = Difference('diff', TEST_FILE1_PATH, TEST_FILE2_PATH, source='source')
    class MockFile(FilesystemFile):
        def compare_details(self, other, source=None):
            return [d]
    difference = MockFile(TEST_FILE1_PATH).compare(MockFile(TEST_FILE2_PATH), source='source')
    assert difference.details[0] == d

@skip_unless_tools_exist('xxd')
def test_with_compare_details_and_fallback():
    class MockFile(FilesystemFile):
        def compare_details(self, other, source=None):
            return []
    difference = MockFile(TEST_FILE1_PATH).compare(MockFile(TEST_FILE2_PATH))
    expected_diff = get_data('binary_expected_diff')
    assert 'yet data differs' in difference.comment
    assert normalize_zeros(difference.unified_diff) == expected_diff

def test_with_compare_details_and_no_actual_differences():
    class MockFile(FilesystemFile):
        def compare_details(self, other, source=None):
            return []
    difference = MockFile(TEST_FILE1_PATH).compare(MockFile(TEST_FILE1_PATH))
    assert difference is None

@skip_unless_tools_exist('xxd')
def test_with_compare_details_and_failed_process():
    output = 'Free Jeremy Hammond'
    class MockFile(FilesystemFile):
        def compare_details(self, other, source=None):
            subprocess.check_output(['sh', '-c', 'echo "%s"; exit 42' % output], shell=False)
            raise Exception('should not be run')
    difference = MockFile(TEST_FILE1_PATH).compare(MockFile(TEST_FILE2_PATH))
    expected_diff = get_data('../data/binary_expected_diff')
    assert output in difference.comment
    assert '42' in difference.comment
    assert normalize_zeros(difference.unified_diff) == expected_diff

@skip_unless_tools_exist('xxd')
def test_with_compare_details_and_parsing_error():
    from diffoscope.exc import OutputParsingError
    class MockFile(FilesystemFile):
        def compare_details(self, other, source=None):
            subprocess.check_output(['sh', '-c', 'exit 0'], shell=False)
            raise OutputParsingError('sh', self)
    difference = MockFile(TEST_FILE1_PATH).compare(MockFile(TEST_FILE2_PATH))
    expected_diff = get_data('../data/binary_expected_diff')
    assert 'Error parsing output' in difference.comment
    assert normalize_zeros(difference.unified_diff) == expected_diff

@skip_unless_tools_exist('xxd')
def test_with_compare_details_and_extraction_error():
    from diffoscope.exc import ContainerExtractionError
    class MockFile(FilesystemFile):
        def compare_details(self, other, source=None):
            subprocess.check_output(['sh', '-c', 'exit 0'], shell=False)
            raise ContainerExtractionError(self.path, Exception())
    difference = MockFile(TEST_FILE1_PATH).compare(MockFile(TEST_FILE2_PATH))
    expected_diff = get_data('../data/binary_expected_diff')
    assert 'Error extracting' in difference.comment
    assert normalize_zeros(difference.unified_diff) == expected_diff

@skip_unless_tools_exist('xxd')
@skip_unless_module_exists('distro')
def test_with_compare_details_and_tool_not_found(monkeypatch):
    from diffoscope.external_tools import EXTERNAL_TOOLS
    monkeypatch.setitem(
        EXTERNAL_TOOLS,
        'nonexistent',
        {
            'debian': 'some-package',
            'arch': 'some-package',
            'fedora': 'some-package',
            'FreeBSD': 'some-package'
        }
    )
    class MockFile(FilesystemFile):
        @tool_required('nonexistent')
        def compare_details(self, other, source=None):
            raise Exception('should not be run')
    difference = MockFile(TEST_FILE1_PATH).compare(MockFile(TEST_FILE2_PATH))
    expected_diff = get_data('binary_expected_diff')
    assert 'nonexistent' in difference.comment
    assert 'some-package' in difference.comment
    assert normalize_zeros(difference.unified_diff) == expected_diff

def test_compare_two_nonexisting_files():
    file1 = MissingFile('/nonexisting1')
    file2 = MissingFile('/nonexisting2')
    difference = file1.compare(file2)
    assert 'non-existing' in difference.comment

def test_symlink_to_dir():
    # Create 2 directories, each containing sub-directory src and symbolic link dst-->src.
    with TemporaryDirectory() as basepath1:
        with TemporaryDirectory() as basepath2:
            src1path = os.path.join(basepath1, 'src')
            dst1path = os.path.join(basepath1, 'lnk')
            src2path = os.path.join(basepath2, 'src')
            dst2path = os.path.join(basepath2, 'lnk')
            mkdir(src1path)
            mkdir(src2path)
            symlink(src1path, dst1path)
            symlink(src2path, dst2path)

            # Compare these directories' content.
            file1 = FilesystemFile(basepath1)
            file2 = FilesystemFile(basepath2)
            assert file1.has_same_content_as(file2) is False