# vim: ft=python fileencoding=utf-8 sts=4 sw=4 et:

# Copyright 2014-2018 Florian Bruhin (The Compiler) <mail@qutebrowser.org>
#
# This file is part of qutebrowser.
#
# qutebrowser 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.
#
# qutebrowser 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 qutebrowser.  If not, see <http://www.gnu.org/licenses/>.

"""Tests for qutebrowser.utils.utils."""

import sys
import enum
import os.path
import io
import logging
import functools
import socket
import re
import shlex
import math

import attr
from PyQt5.QtCore import QUrl
from PyQt5.QtGui import QColor, QClipboard
import pytest
import hypothesis
from hypothesis import strategies

import qutebrowser
import qutebrowser.utils  # for test_qualname
from qutebrowser.utils import utils, qtutils


ELLIPSIS = '\u2026'


class Color(QColor):

    """A QColor with a nicer repr()."""

    def __repr__(self):
        return utils.get_repr(self, constructor=True, red=self.red(),
                              green=self.green(), blue=self.blue(),
                              alpha=self.alpha())


class TestCompactText:

    """Test compact_text."""

    @pytest.mark.parametrize('text, expected', [
        ('foo\nbar', 'foobar'),
        ('  foo  \n  bar  ', 'foobar'),
        ('\nfoo\n', 'foo'),
    ], ids=repr)
    def test_compact_text(self, text, expected):
        """Test folding of newlines."""
        assert utils.compact_text(text) == expected

    @pytest.mark.parametrize('elidelength, text, expected', [
        (None, 'x' * 100, 'x' * 100),
        (6, 'foobar', 'foobar'),
        (5, 'foobar', 'foob' + ELLIPSIS),
        (5, 'foo\nbar', 'foob' + ELLIPSIS),
        (7, 'foo\nbar', 'foobar'),
    ], ids=lambda val: repr(val)[:20])
    def test_eliding(self, elidelength, text, expected):
        """Test eliding."""
        assert utils.compact_text(text, elidelength) == expected


class TestEliding:

    """Test elide."""

    def test_too_small(self):
        """Test eliding to 0 chars which should fail."""
        with pytest.raises(ValueError):
            utils.elide('foo', 0)

    @pytest.mark.parametrize('text, length, expected', [
        ('foo', 1, ELLIPSIS),
        ('foo', 3, 'foo'),
        ('foobar', 3, 'fo' + ELLIPSIS),
    ])
    def test_elided(self, text, length, expected):
        assert utils.elide(text, length) == expected


class TestElidingFilenames:

    """Test elide_filename."""

    def test_too_small(self):
        """Test eliding to less than 3 characters which should fail."""
        with pytest.raises(ValueError):
            utils.elide_filename('foo', 1)

    @pytest.mark.parametrize('filename, length, expected', [
        ('foobar', 3, '...'),
        ('foobar.txt', 50, 'foobar.txt'),
        ('foobarbazqux.py', 10, 'foo...x.py'),
    ])
    def test_elided(self, filename, length, expected):
        assert utils.elide_filename(filename, length) == expected


@pytest.fixture(params=[True, False])
def freezer(request, monkeypatch):
    if request.param and not getattr(sys, 'frozen', False):
        monkeypatch.setattr(sys, 'frozen', True, raising=False)
        monkeypatch.setattr(sys, 'executable', qutebrowser.__file__)
    elif not request.param and getattr(sys, 'frozen', False):
        # Want to test unfrozen tests, but we are frozen
        pytest.skip("Can't run with sys.frozen = True!")


@pytest.mark.usefixtures('freezer')
class TestReadFile:

    """Test read_file."""

    def test_readfile(self):
        """Read a test file."""
        content = utils.read_file(os.path.join('utils', 'testfile'))
        assert content.splitlines()[0] == "Hello World!"

    @pytest.mark.parametrize('filename', ['javascript/scroll.js',
                                          'html/error.html'])
    def test_read_cached_file(self, mocker, filename):
        utils.preload_resources()
        m = mocker.patch('pkg_resources.resource_string')
        utils.read_file(filename)
        m.assert_not_called()

    def test_readfile_binary(self):
        """Read a test file in binary mode."""
        content = utils.read_file(os.path.join('utils', 'testfile'),
                                  binary=True)
        assert content.splitlines()[0] == b"Hello World!"


@pytest.mark.usefixtures('freezer')
def test_resource_filename():
    """Read a test file."""
    filename = utils.resource_filename(os.path.join('utils', 'testfile'))
    with open(filename, 'r', encoding='utf-8') as f:
        assert f.read().splitlines()[0] == "Hello World!"


class TestInterpolateColor:

    """Tests for interpolate_color.

    Attributes:
        white: The Color white as a valid Color for tests.
        white: The Color black as a valid Color for tests.
    """

    @attr.s
    class Colors:

        white = attr.ib()
        black = attr.ib()

    @pytest.fixture
    def colors(self):
        """Example colors to be used."""
        return self.Colors(Color('white'), Color('black'))

    def test_invalid_start(self, colors):
        """Test an invalid start color."""
        with pytest.raises(qtutils.QtValueError):
            utils.interpolate_color(Color(), colors.white, 0)

    def test_invalid_end(self, colors):
        """Test an invalid end color."""
        with pytest.raises(qtutils.QtValueError):
            utils.interpolate_color(colors.white, Color(), 0)

    @pytest.mark.parametrize('perc', [-1, 101])
    def test_invalid_percentage(self, colors, perc):
        """Test an invalid percentage."""
        with pytest.raises(ValueError):
            utils.interpolate_color(colors.white, colors.white, perc)

    def test_invalid_colorspace(self, colors):
        """Test an invalid colorspace."""
        with pytest.raises(ValueError):
            utils.interpolate_color(colors.white, colors.black, 10,
                                    QColor.Cmyk)

    @pytest.mark.parametrize('colorspace', [QColor.Rgb, QColor.Hsv,
                                            QColor.Hsl])
    def test_0_100(self, colors, colorspace):
        """Test 0% and 100% in different colorspaces."""
        white = utils.interpolate_color(colors.white, colors.black, 0,
                                        colorspace)
        black = utils.interpolate_color(colors.white, colors.black, 100,
                                        colorspace)
        assert Color(white) == colors.white
        assert Color(black) == colors.black

    def test_interpolation_rgb(self):
        """Test an interpolation in the RGB colorspace."""
        color = utils.interpolate_color(Color(0, 40, 100), Color(0, 20, 200),
                                        50, QColor.Rgb)
        assert Color(color) == Color(0, 30, 150)

    def test_interpolation_hsv(self):
        """Test an interpolation in the HSV colorspace."""
        start = Color()
        stop = Color()
        start.setHsv(0, 40, 100)
        stop.setHsv(0, 20, 200)
        color = utils.interpolate_color(start, stop, 50, QColor.Hsv)
        expected = Color()
        expected.setHsv(0, 30, 150)
        assert Color(color) == expected

    def test_interpolation_hsl(self):
        """Test an interpolation in the HSL colorspace."""
        start = Color()
        stop = Color()
        start.setHsl(0, 40, 100)
        stop.setHsl(0, 20, 200)
        color = utils.interpolate_color(start, stop, 50, QColor.Hsl)
        expected = Color()
        expected.setHsl(0, 30, 150)
        assert Color(color) == expected

    @pytest.mark.parametrize('percentage, expected', [
        (0, (0, 0, 0)),
        (99, (0, 0, 0)),
        (100, (255, 255, 255)),
    ])
    def test_interpolation_none(self, percentage, expected):
        """Test an interpolation with a gradient turned off."""
        color = utils.interpolate_color(Color(0, 0, 0), Color(255, 255, 255),
                                        percentage, None)
        assert isinstance(color, QColor)
        assert Color(color) == Color(*expected)


@pytest.mark.parametrize('seconds, out', [
    (-1, '-0:01'),
    (0, '0:00'),
    (59, '0:59'),
    (60, '1:00'),
    (60.4, '1:00'),
    (61, '1:01'),
    (-61, '-1:01'),
    (3599, '59:59'),
    (3600, '1:00:00'),
    (3601, '1:00:01'),
    (36000, '10:00:00'),
])
def test_format_seconds(seconds, out):
    assert utils.format_seconds(seconds) == out


class TestFormatSize:

    """Tests for format_size.

    Class attributes:
        TESTS: A list of (input, output) tuples.
    """

    TESTS = [
        (-1024, '-1.00k'),
        (-1, '-1.00'),
        (0, '0.00'),
        (1023, '1023.00'),
        (1024, '1.00k'),
        (1034.24, '1.01k'),
        (1024 * 1024 * 2, '2.00M'),
        (1024 ** 10, '1024.00Y'),
        (None, '?.??'),
    ]

    KILO_TESTS = [(999, '999.00'), (1000, '1.00k'), (1010, '1.01k')]

    @pytest.mark.parametrize('size, out', TESTS)
    def test_format_size(self, size, out):
        """Test format_size with several tests."""
        assert utils.format_size(size) == out

    @pytest.mark.parametrize('size, out', TESTS)
    def test_suffix(self, size, out):
        """Test the suffix option."""
        assert utils.format_size(size, suffix='B') == out + 'B'

    @pytest.mark.parametrize('size, out', KILO_TESTS)
    def test_base(self, size, out):
        """Test with an alternative base."""
        assert utils.format_size(size, base=1000) == out


class TestFakeIOStream:

    """Test FakeIOStream."""

    def _write_func(self, text):
        return text

    def test_flush(self):
        """Smoke-test to see if flushing works."""
        s = utils.FakeIOStream(self._write_func)
        s.flush()

    def test_isatty(self):
        """Make sure isatty() is always false."""
        s = utils.FakeIOStream(self._write_func)
        assert not s.isatty()

    def test_write(self):
        """Make sure writing works."""
        s = utils.FakeIOStream(self._write_func)
        assert s.write('echo') == 'echo'


class TestFakeIO:

    """Test FakeIO."""

    @pytest.fixture(autouse=True)
    def restore_streams(self):
        """Restore sys.stderr/sys.stdout after tests."""
        old_stdout = sys.stdout
        old_stderr = sys.stderr
        yield
        sys.stdout = old_stdout
        sys.stderr = old_stderr

    def test_normal(self, capsys):
        """Test without changing sys.stderr/sys.stdout."""
        data = io.StringIO()
        with utils.fake_io(data.write):
            sys.stdout.write('hello\n')
            sys.stderr.write('world\n')

        out, err = capsys.readouterr()
        assert not out
        assert not err
        assert data.getvalue() == 'hello\nworld\n'

        sys.stdout.write('back to\n')
        sys.stderr.write('normal\n')
        out, err = capsys.readouterr()
        assert out == 'back to\n'
        assert err == 'normal\n'

    def test_stdout_replaced(self, capsys):
        """Test with replaced stdout."""
        data = io.StringIO()
        new_stdout = io.StringIO()
        with utils.fake_io(data.write):
            sys.stdout.write('hello\n')
            sys.stderr.write('world\n')
            sys.stdout = new_stdout

        out, err = capsys.readouterr()
        assert not out
        assert not err
        assert data.getvalue() == 'hello\nworld\n'

        sys.stdout.write('still new\n')
        sys.stderr.write('normal\n')
        out, err = capsys.readouterr()
        assert not out
        assert err == 'normal\n'
        assert new_stdout.getvalue() == 'still new\n'

    def test_stderr_replaced(self, capsys):
        """Test with replaced stderr."""
        data = io.StringIO()
        new_stderr = io.StringIO()
        with utils.fake_io(data.write):
            sys.stdout.write('hello\n')
            sys.stderr.write('world\n')
            sys.stderr = new_stderr

        out, err = capsys.readouterr()
        assert not out
        assert not err
        assert data.getvalue() == 'hello\nworld\n'

        sys.stdout.write('normal\n')
        sys.stderr.write('still new\n')
        out, err = capsys.readouterr()
        assert out == 'normal\n'
        assert not err
        assert new_stderr.getvalue() == 'still new\n'


class GotException(Exception):

    """Exception used for TestDisabledExcepthook."""


def excepthook(_exc, _val, _tb):
    pass


def excepthook_2(_exc, _val, _tb):
    pass


class TestDisabledExcepthook:

    """Test disabled_excepthook.

    This doesn't test much as some things are untestable without triggering
    the excepthook (which is hard to test).
    """

    @pytest.fixture(autouse=True)
    def restore_excepthook(self):
        """Restore sys.excepthook and sys.__excepthook__ after tests."""
        old_excepthook = sys.excepthook
        old_dunder_excepthook = sys.__excepthook__
        yield
        sys.excepthook = old_excepthook
        sys.__excepthook__ = old_dunder_excepthook

    def test_normal(self):
        """Test without changing sys.excepthook."""
        sys.excepthook = excepthook
        assert sys.excepthook is excepthook
        with utils.disabled_excepthook():
            assert sys.excepthook is not excepthook
        assert sys.excepthook is excepthook

    def test_changed(self):
        """Test with changed sys.excepthook."""
        sys.excepthook = excepthook
        with utils.disabled_excepthook():
            assert sys.excepthook is not excepthook
            sys.excepthook = excepthook_2
        assert sys.excepthook is excepthook_2


class TestPreventExceptions:

    """Test prevent_exceptions."""

    @utils.prevent_exceptions(42)
    def func_raising(self):
        raise Exception

    def test_raising(self, caplog):
        """Test with a raising function."""
        with caplog.at_level(logging.ERROR, 'misc'):
            ret = self.func_raising()
        assert ret == 42
        expected = 'Error in test_utils.TestPreventExceptions.func_raising'
        assert caplog.messages == [expected]

    @utils.prevent_exceptions(42)
    def func_not_raising(self):
        return 23

    def test_not_raising(self, caplog):
        """Test with a non-raising function."""
        with caplog.at_level(logging.ERROR, 'misc'):
            ret = self.func_not_raising()
        assert ret == 23
        assert not caplog.records

    @utils.prevent_exceptions(42, True)
    def func_predicate_true(self):
        raise Exception

    def test_predicate_true(self, caplog):
        """Test with a True predicate."""
        with caplog.at_level(logging.ERROR, 'misc'):
            ret = self.func_predicate_true()
        assert ret == 42
        assert len(caplog.records) == 1

    @utils.prevent_exceptions(42, False)
    def func_predicate_false(self):
        raise Exception

    def test_predicate_false(self, caplog):
        """Test with a False predicate."""
        with caplog.at_level(logging.ERROR, 'misc'):
            with pytest.raises(Exception):
                self.func_predicate_false()
        assert not caplog.records


class Obj:

    """Test object for test_get_repr()."""


@pytest.mark.parametrize('constructor, attrs, expected', [
    (False, {}, '<test_utils.Obj>'),
    (False, {'foo': None}, '<test_utils.Obj foo=None>'),
    (False, {'foo': "b'ar", 'baz': 2}, '<test_utils.Obj baz=2 foo="b\'ar">'),
    (True, {}, 'test_utils.Obj()'),
    (True, {'foo': None}, 'test_utils.Obj(foo=None)'),
    (True, {'foo': "te'st", 'bar': 2}, 'test_utils.Obj(bar=2, foo="te\'st")'),
])
def test_get_repr(constructor, attrs, expected):
    """Test get_repr()."""
    assert utils.get_repr(Obj(), constructor, **attrs) == expected


class QualnameObj():

    """Test object for test_qualname."""

    def func(self):
        """Test method for test_qualname."""


def qualname_func(_blah):
    """Test function for test_qualname."""


QUALNAME_OBJ = QualnameObj()


@pytest.mark.parametrize('obj, expected', [
    pytest.param(QUALNAME_OBJ, repr(QUALNAME_OBJ), id='instance'),
    pytest.param(QualnameObj, 'test_utils.QualnameObj', id='class'),
    pytest.param(QualnameObj.func, 'test_utils.QualnameObj.func',
                 id='unbound-method'),
    pytest.param(QualnameObj().func, 'test_utils.QualnameObj.func',
                 id='bound-method'),
    pytest.param(qualname_func, 'test_utils.qualname_func', id='function'),
    pytest.param(functools.partial(qualname_func, True),
                 'test_utils.qualname_func', id='partial'),
    pytest.param(qutebrowser, 'qutebrowser', id='module'),
    pytest.param(qutebrowser.utils, 'qutebrowser.utils', id='submodule'),
    pytest.param(utils, 'qutebrowser.utils.utils', id='from-import'),
])
def test_qualname(obj, expected):
    assert utils.qualname(obj) == expected


class TestIsEnum:

    """Test is_enum."""

    def test_enum(self):
        """Test is_enum with an enum."""
        e = enum.Enum('Foo', 'bar, baz')
        assert utils.is_enum(e)

    def test_class(self):
        """Test is_enum with a non-enum class."""
        class Test:

            """Test class for is_enum."""

        assert not utils.is_enum(Test)

    def test_object(self):
        """Test is_enum with a non-enum object."""
        assert not utils.is_enum(23)


class TestRaises:

    """Test raises."""

    def do_raise(self):
        """Helper function which raises an exception."""
        raise Exception

    def do_nothing(self):
        """Helper function which does nothing."""

    @pytest.mark.parametrize('exception, value, expected', [
        (ValueError, 'a', True),
        ((ValueError, TypeError), 'a', True),
        ((ValueError, TypeError), None, True),

        (ValueError, '1', False),
        ((ValueError, TypeError), 1, False),
    ])
    def test_raises_int(self, exception, value, expected):
        """Test raises with a single exception which gets raised."""
        assert utils.raises(exception, int, value) == expected

    def test_no_args_true(self):
        """Test with no args and an exception which gets raised."""
        assert utils.raises(Exception, self.do_raise)

    def test_no_args_false(self):
        """Test with no args and an exception which does not get raised."""
        assert not utils.raises(Exception, self.do_nothing)

    def test_unrelated_exception(self):
        """Test with an unrelated exception."""
        with pytest.raises(Exception):
            utils.raises(ValueError, self.do_raise)


@pytest.mark.parametrize('inp, enc, expected', [
    ('hello world', 'ascii', 'hello world'),
    ('hellö wörld', 'utf-8', 'hellö wörld'),
    ('hellö wörld', 'ascii', 'hell? w?rld'),
])
def test_force_encoding(inp, enc, expected):
    assert utils.force_encoding(inp, enc) == expected


@pytest.mark.parametrize('inp, expected', [
    pytest.param('normal.txt', 'normal.txt',
                 marks=pytest.mark.fake_os('windows')),
    pytest.param('user/repo issues.mht', 'user_repo issues.mht',
                 marks=pytest.mark.fake_os('windows')),
    pytest.param('<Test\\File> - "*?:|', '_Test_File_ - _____',
                 marks=pytest.mark.fake_os('windows')),
    pytest.param('<Test\\File> - "*?:|', '<Test\\File> - "*?_|',
                 marks=pytest.mark.fake_os('mac')),
    pytest.param('<Test\\File> - "*?:|', '<Test\\File> - "*?:|',
                 marks=pytest.mark.fake_os('posix')),
])
def test_sanitize_filename(inp, expected, monkeypatch):
    assert utils.sanitize_filename(inp) == expected


@pytest.mark.fake_os('windows')
def test_sanitize_filename_empty_replacement():
    name = '/<Bad File>/'
    assert utils.sanitize_filename(name, replacement=None) == 'Bad File'


class TestGetSetClipboard:

    @pytest.fixture(autouse=True)
    def clipboard_mock(self, mocker):
        m = mocker.patch('qutebrowser.utils.utils.QApplication.clipboard',
                         autospec=True)
        clipboard = m()
        clipboard.text.return_value = 'mocked clipboard text'
        mocker.patch('qutebrowser.utils.utils.fake_clipboard', None)
        return clipboard

    def test_set(self, clipboard_mock, caplog):
        utils.set_clipboard('Hello World')
        clipboard_mock.setText.assert_called_with('Hello World',
                                                  mode=QClipboard.Clipboard)
        assert not caplog.records

    def test_set_unsupported_selection(self, clipboard_mock):
        clipboard_mock.supportsSelection.return_value = False
        with pytest.raises(utils.SelectionUnsupportedError):
            utils.set_clipboard('foo', selection=True)

    @pytest.mark.parametrize('selection, what, text, expected', [
        (True, 'primary selection', 'fake text', 'fake text'),
        (False, 'clipboard', 'fake text', 'fake text'),
        (False, 'clipboard', 'füb', r'f\u00fcb'),
    ])
    def test_set_logging(self, clipboard_mock, caplog, selection, what,
                         text, expected):
        utils.log_clipboard = True
        utils.set_clipboard(text, selection=selection)
        assert not clipboard_mock.setText.called
        expected = 'Setting fake {}: "{}"'.format(what, expected)
        assert caplog.messages[0] == expected

    def test_get(self):
        assert utils.get_clipboard() == 'mocked clipboard text'

    @pytest.mark.parametrize('selection', [True, False])
    def test_get_empty(self, clipboard_mock, selection):
        clipboard_mock.text.return_value = ''
        with pytest.raises(utils.ClipboardEmptyError):
            utils.get_clipboard(selection=selection)

    def test_get_unsupported_selection(self, clipboard_mock):
        clipboard_mock.supportsSelection.return_value = False
        with pytest.raises(utils.SelectionUnsupportedError):
            utils.get_clipboard(selection=True)

    def test_get_unsupported_selection_fallback(self, clipboard_mock):
        clipboard_mock.supportsSelection.return_value = False
        clipboard_mock.text.return_value = 'text'
        assert utils.get_clipboard(selection=True, fallback=True) == 'text'

    @pytest.mark.parametrize('selection', [True, False])
    def test_get_fake_clipboard(self, selection):
        utils.fake_clipboard = 'fake clipboard text'
        utils.get_clipboard(selection=selection)
        assert utils.fake_clipboard is None

    @pytest.mark.parametrize('selection', [True, False])
    def test_supports_selection(self, clipboard_mock, selection):
        clipboard_mock.supportsSelection.return_value = selection
        assert utils.supports_selection() == selection

    def test_fallback_without_selection(self):
        with pytest.raises(ValueError):
            utils.get_clipboard(fallback=True)


def test_random_port():
    port = utils.random_port()
    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    sock.bind(('localhost', port))
    sock.close()


class TestOpenFile:

    @pytest.mark.not_frozen
    def test_cmdline_without_argument(self, caplog, config_stub):
        executable = shlex.quote(sys.executable)
        cmdline = '{} -c pass'.format(executable)
        utils.open_file('/foo/bar', cmdline)
        result = caplog.messages[0]
        assert re.fullmatch(
            r'Opening /foo/bar with \[.*python.*/foo/bar.*\]', result)

    @pytest.mark.not_frozen
    def test_cmdline_with_argument(self, caplog, config_stub):
        executable = shlex.quote(sys.executable)
        cmdline = '{} -c pass {{}} raboof'.format(executable)
        utils.open_file('/foo/bar', cmdline)
        result = caplog.messages[0]
        assert re.fullmatch(
            r"Opening /foo/bar with \[.*python.*/foo/bar.*'raboof'\]", result)

    @pytest.mark.not_frozen
    def test_setting_override(self, caplog, config_stub):
        executable = shlex.quote(sys.executable)
        cmdline = '{} -c pass'.format(executable)
        config_stub.val.downloads.open_dispatcher = cmdline
        utils.open_file('/foo/bar')
        result = caplog.messages[1]
        assert re.fullmatch(
            r"Opening /foo/bar with \[.*python.*/foo/bar.*\]", result)

    def test_system_default_application(self, caplog, config_stub, mocker):
        m = mocker.patch('PyQt5.QtGui.QDesktopServices.openUrl', spec={},
                         new_callable=mocker.Mock)
        utils.open_file('/foo/bar')
        result = caplog.messages[0]
        assert re.fullmatch(
            r"Opening /foo/bar with the system application", result)
        m.assert_called_with(QUrl('file:///foo/bar'))


def test_unused():
    utils.unused(None)


@pytest.mark.parametrize('path, expected', [
    ('E:', 'E:\\'),
    ('e:', 'e:\\'),
    ('E:foo', 'E:foo'),
    ('E:\\', 'E:\\'),
    ('E:\\foo', 'E:\\foo'),
    ('foo:', 'foo:'),
    ('foo:bar', 'foo:bar'),
])
def test_expand_windows_drive(path, expected):
    assert utils.expand_windows_drive(path) == expected


class TestYaml:

    def test_load(self):
        assert utils.yaml_load("[1, 2]") == [1, 2]

    def test_load_file(self, tmpdir):
        tmpfile = tmpdir / 'foo.yml'
        tmpfile.write('[1, 2]')
        with tmpfile.open(encoding='utf-8') as f:
            assert utils.yaml_load(f) == [1, 2]

    def test_dump(self):
        assert utils.yaml_dump([1, 2]) == '- 1\n- 2\n'

    def test_dump_file(self, tmpdir):
        tmpfile = tmpdir / 'foo.yml'
        with tmpfile.open('w', encoding='utf-8') as f:
            utils.yaml_dump([1, 2], f)
        assert tmpfile.read() == '- 1\n- 2\n'


@pytest.mark.parametrize('elems, n, expected', [
    ([], 1, []),
    ([1], 1, [[1]]),
    ([1, 2], 2, [[1, 2]]),
    ([1, 2, 3, 4], 2, [[1, 2], [3, 4]]),
])
def test_chunk(elems, n, expected):
    assert list(utils.chunk(elems, n)) == expected


@pytest.mark.parametrize('n', [-1, 0])
def test_chunk_invalid(n):
    with pytest.raises(ValueError):
        list(utils.chunk([], n))


@pytest.mark.parametrize('filename, expected', [
    ('test.jpg', 'image/jpeg'),
    ('test.blabla', 'application/octet-stream'),
])
def test_guess_mimetype(filename, expected):
    assert utils.guess_mimetype(filename, fallback=True) == expected


def test_guess_mimetype_no_fallback():
    with pytest.raises(ValueError):
        utils.guess_mimetype('test.blabla')


@hypothesis.given(number=strategies.integers(min_value=1),
                  base=strategies.integers(min_value=2))
@hypothesis.example(number=125, base=5)
def test_ceil_log_hypothesis(number, base):
    exponent = utils.ceil_log(number, base)
    assert base ** exponent >= number
    # With base=2, number=1 we get exponent=1
    # 2**1 > 1, but 2**0 == 1.
    if exponent > 1:
        assert base ** (exponent - 1) < number


@pytest.mark.parametrize('number, base', [(64, 0), (0, 64), (64, -1),
                                          (-1, 64), (1, 1)])
def test_ceil_log_invalid(number, base):
    with pytest.raises(Exception):  # ValueError/ZeroDivisionError
        math.log(number, base)
    with pytest.raises(ValueError):
        utils.ceil_log(number, base)