OCRmyPDF/tests/test_helpers.py

# SPDX-FileCopyrightText: 2022 James R. Barlow
# SPDX-License-Identifier: MPL-2.0

from __future__ import annotations

import logging
import multiprocessing
import os
from pathlib import Path
from unittest.mock import MagicMock

import pytest
from packaging.version import Version

from ocrmypdf import helpers
from ocrmypdf.helpers import running_in_docker

needs_symlink = pytest.mark.skipif(os.name == 'nt', reason='needs posix symlink')
windows_only = pytest.mark.skipif(os.name != 'nt', reason="Windows test")


class TestSafeSymlink:
    def test_safe_symlink_link_self(self, tmp_path, caplog):
        helpers.safe_symlink(tmp_path / 'self', tmp_path / 'self')
        assert caplog.record_tuples[0][1] == logging.WARNING

    def test_safe_symlink_overwrite(self, tmp_path):
        (tmp_path / 'regular_file').touch()
        with pytest.raises(FileExistsError):
            helpers.safe_symlink(tmp_path / 'input', tmp_path / 'regular_file')

    @needs_symlink
    def test_safe_symlink_relink(self, tmp_path):
        (tmp_path / 'regular_file_a').touch()
        (tmp_path / 'regular_file_b').write_bytes(b'ABC')
        (tmp_path / 'link').symlink_to(tmp_path / 'regular_file_a')
        helpers.safe_symlink(tmp_path / 'regular_file_b', tmp_path / 'link')
        assert (tmp_path / 'link').samefile(tmp_path / 'regular_file_b') or (
            tmp_path / 'link'
        ).read_bytes() == b'ABC'


def test_no_cpu_count(monkeypatch):
    invoked = False

    def cpu_count_raises():
        nonlocal invoked
        invoked = True
        raise NotImplementedError()

    monkeypatch.setattr(multiprocessing, 'cpu_count', cpu_count_raises)
    with pytest.warns(expected_warning=UserWarning):
        assert helpers.available_cpu_count() == 1
    assert invoked, "Patched function called during test"


skipif_docker = pytest.mark.skipif(running_in_docker(), reason="fails on Docker")


class TestFileIsWritable:
    @pytest.fixture
    def non_existent(self, tmp_path):
        return tmp_path / 'nofile'

    @pytest.fixture
    def basic_file(self, tmp_path):
        basic = tmp_path / 'basic'
        basic.touch()
        return basic

    def test_plain(self, non_existent):
        assert helpers.is_file_writable(non_existent)

    @needs_symlink
    def test_symlink_loop(self, tmp_path):
        loop = tmp_path / 'loop'
        loop.symlink_to(loop)
        assert not helpers.is_file_writable(loop)

    @skipif_docker
    def test_chmod(self, basic_file):
        assert helpers.is_file_writable(basic_file)
        basic_file.chmod(0o400)
        assert not helpers.is_file_writable(basic_file)
        basic_file.chmod(0o000)
        assert not helpers.is_file_writable(basic_file)

    def test_permission_error(self, basic_file):
        pathmock = MagicMock(spec_set=basic_file)
        pathmock.is_symlink.return_value = False
        pathmock.exists.return_value = True
        pathmock.is_file.side_effect = PermissionError
        assert not helpers.is_file_writable(pathmock)


@windows_only
def test_gs_install_locations():
    # pylint: disable=import-outside-toplevel
    from ocrmypdf.subprocess._windows import _gs_version_in_path_key

    assert _gs_version_in_path_key(Path("C:\\Program Files\\gs\\gs9.52\\bin")) == (
        'gs',
        Version('9.52'),
    )


@windows_only
def test_shim_paths(tmp_path):
    # pylint: disable=import-outside-toplevel
    from ocrmypdf.subprocess._windows import shim_env_path

    progfiles = tmp_path / 'Program Files'
    progfiles.mkdir()
    (progfiles / 'tesseract-ocr').mkdir()
    (progfiles / 'gs' / '9.51' / 'bin').mkdir(parents=True)
    (progfiles / 'gs' / 'gs9.52.3' / 'bin').mkdir(parents=True)
    syspath = tmp_path / 'bin'
    env = {'PROGRAMFILES': str(progfiles), 'PATH': str(syspath)}

    result_str = shim_env_path(env=env)
    results = result_str.split(os.pathsep)
    assert results[0] == str(syspath), results
    assert results[-3].endswith('tesseract-ocr'), results
    assert results[-2].endswith(os.path.join('gs9.52.3', 'bin')), results
    assert results[-1].endswith(os.path.join('gs', '9.51', 'bin')), results


def test_resolution():
    Resolution = helpers.Resolution
    dpi_100 = Resolution(100, 100)
    dpi_200 = Resolution(200, 200)
    assert dpi_100.is_square
    assert not Resolution(100, 200).is_square
    assert dpi_100 == Resolution(100, 100)
    assert str(dpi_100) != str(dpi_200)
    assert dpi_100.take_max([200, 300], [400]) == Resolution(300, 400)