/brz/remove-bazaar

# Copyright (C) 2005, 2006 Canonical Ltd

#

# This program 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 2 of the License, or

# (at your option) any later version.

#

# This program 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 this program; if not, write to the Free Software

# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

"""Tests for the osutils wrapper."""

import errno

import os

import socket

import stat

import sys

import bzrlib

from bzrlib import (

    errors,

    osutils,

    )

from bzrlib.errors import BzrBadParameterNotUnicode, InvalidURL

from bzrlib.tests import (

        StringIOWrapper,

        TestCase, 

        TestCaseInTempDir, 

        TestSkipped,

        )

class TestOSUtils(TestCaseInTempDir):

    def test_contains_whitespace(self):

        self.failUnless(osutils.contains_whitespace(u' '))

        self.failUnless(osutils.contains_whitespace(u'hello there'))

        self.failUnless(osutils.contains_whitespace(u'hellothere\n'))

        self.failUnless(osutils.contains_whitespace(u'hello\nthere'))

        self.failUnless(osutils.contains_whitespace(u'hello\rthere'))

        self.failUnless(osutils.contains_whitespace(u'hello\tthere'))

        # \xa0 is "Non-breaking-space" which on some python locales thinks it

        # is whitespace, but we do not.

        self.failIf(osutils.contains_whitespace(u''))

        self.failIf(osutils.contains_whitespace(u'hellothere'))

        self.failIf(osutils.contains_whitespace(u'hello\xa0there'))

    def test_fancy_rename(self):

        # This should work everywhere

        def rename(a, b):

            osutils.fancy_rename(a, b,

                    rename_func=os.rename,

                    unlink_func=os.unlink)

        open('a', 'wb').write('something in a\n')

        rename('a', 'b')

        self.failIfExists('a')

        self.failUnlessExists('b')

        self.check_file_contents('b', 'something in a\n')

        open('a', 'wb').write('new something in a\n')

        rename('b', 'a')

        self.check_file_contents('a', 'something in a\n')

    def test_rename(self):

        # Rename should be semi-atomic on all platforms

        open('a', 'wb').write('something in a\n')

        osutils.rename('a', 'b')

        self.failIfExists('a')

        self.failUnlessExists('b')

        self.check_file_contents('b', 'something in a\n')

        open('a', 'wb').write('new something in a\n')

        osutils.rename('b', 'a')

        self.check_file_contents('a', 'something in a\n')

    # TODO: test fancy_rename using a MemoryTransport

    def test_01_rand_chars_empty(self):

        result = osutils.rand_chars(0)

        self.assertEqual(result, '')

    def test_02_rand_chars_100(self):

        result = osutils.rand_chars(100)

        self.assertEqual(len(result), 100)

        self.assertEqual(type(result), str)

        self.assertContainsRe(result, r'^[a-z0-9]{100}$')

    def test_is_inside(self):

        is_inside = osutils.is_inside

        self.assertTrue(is_inside('src', 'src/foo.c'))

        self.assertFalse(is_inside('src', 'srccontrol'))

        self.assertTrue(is_inside('src', 'src/a/a/a/foo.c'))

        self.assertTrue(is_inside('foo.c', 'foo.c'))

        self.assertFalse(is_inside('foo.c', ''))

        self.assertTrue(is_inside('', 'foo.c'))

    def test_rmtree(self):

        # Check to remove tree with read-only files/dirs

        os.mkdir('dir')

        f = file('dir/file', 'w')

        f.write('spam')

        f.close()

        # would like to also try making the directory readonly, but at the

        # moment python shutil.rmtree doesn't handle that properly - it would

        # need to chmod the directory before removing things inside it - deferred

        # for now -- mbp 20060505

        # osutils.make_readonly('dir')

        osutils.make_readonly('dir/file')

        osutils.rmtree('dir')

        self.failIfExists('dir/file')

        self.failIfExists('dir')

    def test_file_kind(self):

        self.build_tree(['file', 'dir/'])

        self.assertEquals('file', osutils.file_kind('file'))

        self.assertEquals('directory', osutils.file_kind('dir/'))

        if osutils.has_symlinks():

            os.symlink('symlink', 'symlink')

            self.assertEquals('symlink', osutils.file_kind('symlink'))

        # TODO: jam 20060529 Test a block device

        try:

            os.lstat('/dev/null')

        except OSError, e:

            if e.errno not in (errno.ENOENT,):

                raise

        else:

            self.assertEquals('chardev', osutils.file_kind('/dev/null'))

        mkfifo = getattr(os, 'mkfifo', None)

        if mkfifo:

            mkfifo('fifo')

            try:

                self.assertEquals('fifo', osutils.file_kind('fifo'))

            finally:

                os.remove('fifo')

        AF_UNIX = getattr(socket, 'AF_UNIX', None)

        if AF_UNIX:

            s = socket.socket(AF_UNIX)

            s.bind('socket')

            try:

                self.assertEquals('socket', osutils.file_kind('socket'))

            finally:

                os.remove('socket')

    def test_get_umask(self):

        if sys.platform == 'win32':

            # umask always returns '0', no way to set it

            self.assertEqual(0, osutils.get_umask())

            return

        orig_umask = osutils.get_umask()

        try:

            os.umask(0222)

            self.assertEqual(0222, osutils.get_umask())

            os.umask(0022)

            self.assertEqual(0022, osutils.get_umask())

            os.umask(0002)

            self.assertEqual(0002, osutils.get_umask())

            os.umask(0027)

            self.assertEqual(0027, osutils.get_umask())

        finally:

            os.umask(orig_umask)

    def assertFormatedDelta(self, expected, seconds):

        """Assert osutils.format_delta formats as expected"""

        actual = osutils.format_delta(seconds)

        self.assertEqual(expected, actual)

    def test_format_delta(self):

        self.assertFormatedDelta('0 seconds ago', 0)

        self.assertFormatedDelta('1 second ago', 1)

        self.assertFormatedDelta('10 seconds ago', 10)

        self.assertFormatedDelta('59 seconds ago', 59)

        self.assertFormatedDelta('89 seconds ago', 89)

        self.assertFormatedDelta('1 minute, 30 seconds ago', 90)

        self.assertFormatedDelta('3 minutes, 0 seconds ago', 180)

        self.assertFormatedDelta('3 minutes, 1 second ago', 181)

        self.assertFormatedDelta('10 minutes, 15 seconds ago', 615)

        self.assertFormatedDelta('30 minutes, 59 seconds ago', 1859)

        self.assertFormatedDelta('31 minutes, 0 seconds ago', 1860)

        self.assertFormatedDelta('60 minutes, 0 seconds ago', 3600)

        self.assertFormatedDelta('89 minutes, 59 seconds ago', 5399)

        self.assertFormatedDelta('1 hour, 30 minutes ago', 5400)

        self.assertFormatedDelta('2 hours, 30 minutes ago', 9017)

        self.assertFormatedDelta('10 hours, 0 minutes ago', 36000)

        self.assertFormatedDelta('24 hours, 0 minutes ago', 86400)

        self.assertFormatedDelta('35 hours, 59 minutes ago', 129599)

        self.assertFormatedDelta('36 hours, 0 minutes ago', 129600)

        self.assertFormatedDelta('36 hours, 0 minutes ago', 129601)

        self.assertFormatedDelta('36 hours, 1 minute ago', 129660)

        self.assertFormatedDelta('36 hours, 1 minute ago', 129661)

        self.assertFormatedDelta('84 hours, 10 minutes ago', 303002)

        # We handle when time steps the wrong direction because computers

        # don't have synchronized clocks.

        self.assertFormatedDelta('84 hours, 10 minutes in the future', -303002)

        self.assertFormatedDelta('1 second in the future', -1)

        self.assertFormatedDelta('2 seconds in the future', -2)

    def test_dereference_path(self):

        if not osutils.has_symlinks():

            raise TestSkipped('Symlinks are not supported on this platform')

        cwd = osutils.realpath('.')

        os.mkdir('bar')

        bar_path = osutils.pathjoin(cwd, 'bar')

        # Using './' to avoid bug #1213894 (first path component not

        # dereferenced) in Python 2.4.1 and earlier

        self.assertEqual(bar_path, osutils.realpath('./bar'))

        os.symlink('bar', 'foo')

        self.assertEqual(bar_path, osutils.realpath('./foo'))

        # Does not dereference terminal symlinks

        foo_path = osutils.pathjoin(cwd, 'foo')

        self.assertEqual(foo_path, osutils.dereference_path('./foo'))

        # Dereferences parent symlinks

        os.mkdir('bar/baz')

        baz_path = osutils.pathjoin(bar_path, 'baz')

        self.assertEqual(baz_path, osutils.dereference_path('./foo/baz'))

        # Dereferences parent symlinks that are the first path element

        self.assertEqual(baz_path, osutils.dereference_path('foo/baz'))

        # Dereferences parent symlinks in absolute paths

        foo_baz_path = osutils.pathjoin(foo_path, 'baz')

        self.assertEqual(baz_path, osutils.dereference_path(foo_baz_path))

class TestSafeUnicode(TestCase):

    def test_from_ascii_string(self):

        self.assertEqual(u'foobar', osutils.safe_unicode('foobar'))

    def test_from_unicode_string_ascii_contents(self):

        self.assertEqual(u'bargam', osutils.safe_unicode(u'bargam'))

    def test_from_unicode_string_unicode_contents(self):

        self.assertEqual(u'bargam\xae', osutils.safe_unicode(u'bargam\xae'))

    def test_from_utf8_string(self):

        self.assertEqual(u'foo\xae', osutils.safe_unicode('foo\xc2\xae'))

    def test_bad_utf8_string(self):

        self.assertRaises(BzrBadParameterNotUnicode,

                          osutils.safe_unicode,

                          '\xbb\xbb')

class TestWin32Funcs(TestCase):

    """Test that the _win32 versions of os utilities return appropriate paths."""

    def test_abspath(self):

        self.assertEqual('C:/foo', osutils._win32_abspath('C:\\foo'))

        self.assertEqual('C:/foo', osutils._win32_abspath('C:/foo'))

    def test_realpath(self):

        self.assertEqual('C:/foo', osutils._win32_realpath('C:\\foo'))

        self.assertEqual('C:/foo', osutils._win32_realpath('C:/foo'))

    def test_pathjoin(self):

        self.assertEqual('path/to/foo', osutils._win32_pathjoin('path', 'to', 'foo'))

        self.assertEqual('C:/foo', osutils._win32_pathjoin('path\\to', 'C:\\foo'))

        self.assertEqual('C:/foo', osutils._win32_pathjoin('path/to', 'C:/foo'))

        self.assertEqual('path/to/foo', osutils._win32_pathjoin('path/to/', 'foo'))

        self.assertEqual('/foo', osutils._win32_pathjoin('C:/path/to/', '/foo'))

        self.assertEqual('/foo', osutils._win32_pathjoin('C:\\path\\to\\', '\\foo'))

    def test_normpath(self):

        self.assertEqual('path/to/foo', osutils._win32_normpath(r'path\\from\..\to\.\foo'))

        self.assertEqual('path/to/foo', osutils._win32_normpath('path//from/../to/./foo'))

    def test_getcwd(self):

        cwd = osutils._win32_getcwd()

        os_cwd = os.getcwdu()

        self.assertEqual(os_cwd[1:].replace('\\', '/'), cwd[1:])

        # win32 is inconsistent whether it returns lower or upper case

        # and even if it was consistent the user might type the other

        # so we force it to uppercase

        # running python.exe under cmd.exe return capital C:\\

        # running win32 python inside a cygwin shell returns lowercase

        self.assertEqual(os_cwd[0].upper(), cwd[0])

    def test_fixdrive(self):

        self.assertEqual('H:/foo', osutils._win32_fixdrive('h:/foo'))

        self.assertEqual('H:/foo', osutils._win32_fixdrive('H:/foo'))

        self.assertEqual('C:\\foo', osutils._win32_fixdrive('c:\\foo'))

class TestWin32FuncsDirs(TestCaseInTempDir):

    """Test win32 functions that create files."""

    def test_getcwd(self):

        # Make sure getcwd can handle unicode filenames

        try:

            os.mkdir(u'mu-\xb5')

        except UnicodeError:

            raise TestSkipped("Unable to create Unicode filename")

        os.chdir(u'mu-\xb5')

        # TODO: jam 20060427 This will probably fail on Mac OSX because

        #       it will change the normalization of B\xe5gfors

        #       Consider using a different unicode character, or make

        #       osutils.getcwd() renormalize the path.

        self.assertEndsWith(osutils._win32_getcwd(), u'mu-\xb5')

    def test_mkdtemp(self):

        tmpdir = osutils._win32_mkdtemp(dir='.')

        self.assertFalse('\\' in tmpdir)

    def test_rename(self):

        a = open('a', 'wb')

        a.write('foo\n')

        a.close()

        b = open('b', 'wb')

        b.write('baz\n')

        b.close()

        osutils._win32_rename('b', 'a')

        self.failUnlessExists('a')

        self.failIfExists('b')

        self.assertFileEqual('baz\n', 'a')

    def test_rename_missing_file(self):

        a = open('a', 'wb')

        a.write('foo\n')

        a.close()

        try:

            osutils._win32_rename('b', 'a')

        except (IOError, OSError), e:

            self.assertEqual(errno.ENOENT, e.errno)

        self.assertFileEqual('foo\n', 'a')

    def test_rename_missing_dir(self):

        os.mkdir('a')

        try:

            osutils._win32_rename('b', 'a')

        except (IOError, OSError), e:

            self.assertEqual(errno.ENOENT, e.errno)

    def test_rename_current_dir(self):

        os.mkdir('a')

        os.chdir('a')

        # You can't rename the working directory

        # doing rename non-existant . usually

        # just raises ENOENT, since non-existant

        # doesn't exist.

        try:

            osutils._win32_rename('b', '.')

        except (IOError, OSError), e:

            self.assertEqual(errno.ENOENT, e.errno)

    def test_splitpath(self):

        def check(expected, path):

            self.assertEqual(expected, osutils.splitpath(path))

        check(['a'], 'a')

        check(['a', 'b'], 'a/b')

        check(['a', 'b'], 'a/./b')

        check(['a', '.b'], 'a/.b')

        check(['a', '.b'], 'a\\.b')

        self.assertRaises(errors.BzrError, osutils.splitpath, 'a/../b')

class TestMacFuncsDirs(TestCaseInTempDir):

    """Test mac special functions that require directories."""

    def test_getcwd(self):

        # On Mac, this will actually create Ba\u030agfors

        # but chdir will still work, because it accepts both paths

        try:

            os.mkdir(u'B\xe5gfors')

        except UnicodeError:

            raise TestSkipped("Unable to create Unicode filename")

        os.chdir(u'B\xe5gfors')

        self.assertEndsWith(osutils._mac_getcwd(), u'B\xe5gfors')

    def test_getcwd_nonnorm(self):

        # Test that _mac_getcwd() will normalize this path

        try:

            os.mkdir(u'Ba\u030agfors')

        except UnicodeError:

            raise TestSkipped("Unable to create Unicode filename")

        os.chdir(u'Ba\u030agfors')

        self.assertEndsWith(osutils._mac_getcwd(), u'B\xe5gfors')

class TestSplitLines(TestCase):

    def test_split_unicode(self):

        self.assertEqual([u'foo\n', u'bar\xae'],

                         osutils.split_lines(u'foo\nbar\xae'))

        self.assertEqual([u'foo\n', u'bar\xae\n'],

                         osutils.split_lines(u'foo\nbar\xae\n'))

    def test_split_with_carriage_returns(self):

        self.assertEqual(['foo\rbar\n'],

                         osutils.split_lines('foo\rbar\n'))

class TestWalkDirs(TestCaseInTempDir):

    def test_walkdirs(self):

        tree = [

            '.bzr',

            '0file',

            '1dir/',

            '1dir/0file',

            '1dir/1dir/',

            '2file'

            ]

        self.build_tree(tree)

        expected_dirblocks = [

                (('', '.'),

                 [('0file', '0file', 'file'),

                  ('1dir', '1dir', 'directory'),

                  ('2file', '2file', 'file'),

                 ]

                ),

                (('1dir', './1dir'),

                 [('1dir/0file', '0file', 'file'),

                  ('1dir/1dir', '1dir', 'directory'),

                 ]

                ),

                (('1dir/1dir', './1dir/1dir'),

                 [

                 ]

                ),

            ]

        result = []

        found_bzrdir = False

        for dirdetail, dirblock in osutils.walkdirs('.'):

            if len(dirblock) and dirblock[0][1] == '.bzr':

                # this tests the filtering of selected paths

                found_bzrdir = True

                del dirblock[0]

            result.append((dirdetail, dirblock))

        self.assertTrue(found_bzrdir)

        self.assertEqual(expected_dirblocks,

            [(dirinfo, [line[0:3] for line in block]) for dirinfo, block in result])

        # you can search a subdir only, with a supplied prefix.

        result = []

        for dirblock in osutils.walkdirs('./1dir', '1dir'):

            result.append(dirblock)

        self.assertEqual(expected_dirblocks[1:],

            [(dirinfo, [line[0:3] for line in block]) for dirinfo, block in result])

    def assertPathCompare(self, path_less, path_greater):

        """check that path_less and path_greater compare correctly."""

        self.assertEqual(0, osutils.compare_paths_prefix_order(

            path_less, path_less))

        self.assertEqual(0, osutils.compare_paths_prefix_order(

            path_greater, path_greater))

        self.assertEqual(-1, osutils.compare_paths_prefix_order(

            path_less, path_greater))

        self.assertEqual(1, osutils.compare_paths_prefix_order(

            path_greater, path_less))

    def test_compare_paths_prefix_order(self):

        # root before all else

        self.assertPathCompare("/", "/a")

        # alpha within a dir

        self.assertPathCompare("/a", "/b")

        self.assertPathCompare("/b", "/z")

        # high dirs before lower.

        self.assertPathCompare("/z", "/a/a")

        # except if the deeper dir should be output first

        self.assertPathCompare("/a/b/c", "/d/g")

        # lexical betwen dirs of the same height

        self.assertPathCompare("/a/z", "/z/z")

        self.assertPathCompare("/a/c/z", "/a/d/e")

        # this should also be consistent for no leading / paths

        # root before all else

        self.assertPathCompare("", "a")

        # alpha within a dir

        self.assertPathCompare("a", "b")

        self.assertPathCompare("b", "z")

        # high dirs before lower.

        self.assertPathCompare("z", "a/a")

        # except if the deeper dir should be output first

        self.assertPathCompare("a/b/c", "d/g")

        # lexical betwen dirs of the same height

        self.assertPathCompare("a/z", "z/z")

        self.assertPathCompare("a/c/z", "a/d/e")

    def test_path_prefix_sorting(self):

        """Doing a sort on path prefix should match our sample data."""

        original_paths = [

            'a',

            'a/b',

            'a/b/c',

            'b',

            'b/c',

            'd',

            'd/e',

            'd/e/f',

            'd/f',

            'd/g',

            'g',

            ]

        dir_sorted_paths = [

            'a',

            'b',

            'd',

            'g',

            'a/b',

            'a/b/c',

            'b/c',

            'd/e',

            'd/f',

            'd/g',

            'd/e/f',

            ]

        self.assertEqual(

            dir_sorted_paths,

            sorted(original_paths, key=osutils.path_prefix_key))

        # using the comparison routine shoudl work too:

        self.assertEqual(

            dir_sorted_paths,

            sorted(original_paths, cmp=osutils.compare_paths_prefix_order))

class TestCopyTree(TestCaseInTempDir):

    def test_copy_basic_tree(self):

        self.build_tree(['source/', 'source/a', 'source/b/', 'source/b/c'])

        osutils.copy_tree('source', 'target')

        self.assertEqual(['a', 'b'], sorted(os.listdir('target')))

        self.assertEqual(['c'], os.listdir('target/b'))

    def test_copy_tree_target_exists(self):

        self.build_tree(['source/', 'source/a', 'source/b/', 'source/b/c',

                         'target/'])

        osutils.copy_tree('source', 'target')

        self.assertEqual(['a', 'b'], sorted(os.listdir('target')))

        self.assertEqual(['c'], os.listdir('target/b'))

    def test_copy_tree_symlinks(self):

        if not osutils.has_symlinks():

            return

        self.build_tree(['source/'])

        os.symlink('a/generic/path', 'source/lnk')

        osutils.copy_tree('source', 'target')

        self.assertEqual(['lnk'], os.listdir('target'))

        self.assertEqual('a/generic/path', os.readlink('target/lnk'))

    def test_copy_tree_handlers(self):

        processed_files = []

        processed_links = []

        def file_handler(from_path, to_path):

            processed_files.append(('f', from_path, to_path))

        def dir_handler(from_path, to_path):

            processed_files.append(('d', from_path, to_path))

        def link_handler(from_path, to_path):

            processed_links.append((from_path, to_path))

        handlers = {'file':file_handler,

                    'directory':dir_handler,

                    'symlink':link_handler,

                   }

        self.build_tree(['source/', 'source/a', 'source/b/', 'source/b/c'])

        if osutils.has_symlinks():

            os.symlink('a/generic/path', 'source/lnk')

        osutils.copy_tree('source', 'target', handlers=handlers)

        self.assertEqual([('d', 'source', 'target'),

                          ('f', 'source/a', 'target/a'),

                          ('d', 'source/b', 'target/b'),

                          ('f', 'source/b/c', 'target/b/c'),

                         ], processed_files)

        self.failIfExists('target')

        if osutils.has_symlinks():

            self.assertEqual([('source/lnk', 'target/lnk')], processed_links)

#class TestTerminalEncoding has been moved to test_osutils_encodings.py

# [bialix] 2006/12/26

class TestSetUnsetEnv(TestCase):

    """Test updating the environment"""

    def setUp(self):

        super(TestSetUnsetEnv, self).setUp()

        self.assertEqual(None, os.environ.get('BZR_TEST_ENV_VAR'),

                         'Environment was not cleaned up properly.'

                         ' Variable BZR_TEST_ENV_VAR should not exist.')

        def cleanup():

            if 'BZR_TEST_ENV_VAR' in os.environ:

                del os.environ['BZR_TEST_ENV_VAR']

        self.addCleanup(cleanup)

    def test_set(self):

        """Test that we can set an env variable"""

        old = osutils.set_or_unset_env('BZR_TEST_ENV_VAR', 'foo')

        self.assertEqual(None, old)

        self.assertEqual('foo', os.environ.get('BZR_TEST_ENV_VAR'))

    def test_double_set(self):

        """Test that we get the old value out"""

        osutils.set_or_unset_env('BZR_TEST_ENV_VAR', 'foo')

        old = osutils.set_or_unset_env('BZR_TEST_ENV_VAR', 'bar')

        self.assertEqual('foo', old)

        self.assertEqual('bar', os.environ.get('BZR_TEST_ENV_VAR'))

    def test_unicode(self):

        """Environment can only contain plain strings

        So Unicode strings must be encoded.

        """

        # Try a few different characters, to see if we can get

        # one that will be valid in the user_encoding

        possible_vals = [u'm\xb5', u'\xe1', u'\u0410']

        for uni_val in possible_vals:

            try:

                env_val = uni_val.encode(bzrlib.user_encoding)

            except UnicodeEncodeError:

                # Try a different character

                pass

            else:

                break

        else:

            raise TestSkipped('Cannot find a unicode character that works in'

                              ' encoding %s' % (bzrlib.user_encoding,))

        old = osutils.set_or_unset_env('BZR_TEST_ENV_VAR', uni_val)

        self.assertEqual(env_val, os.environ.get('BZR_TEST_ENV_VAR'))

    def test_unset(self):

        """Test that passing None will remove the env var"""

        osutils.set_or_unset_env('BZR_TEST_ENV_VAR', 'foo')

        old = osutils.set_or_unset_env('BZR_TEST_ENV_VAR', None)

        self.assertEqual('foo', old)

        self.assertEqual(None, os.environ.get('BZR_TEST_ENV_VAR'))

        self.failIf('BZR_TEST_ENV_VAR' in os.environ)

class TestLocalTimeOffset(TestCase):

    def test_local_time_offset(self):

        """Test that local_time_offset() returns a sane value."""

        offset = osutils.local_time_offset()

        self.assertTrue(isinstance(offset, int))

        # Test that the offset is no more than a eighteen hours in

        # either direction.

        # Time zone handling is system specific, so it is difficult to

        # do more specific tests, but a value outside of this range is

        # probably wrong.

        eighteen_hours = 18 * 3600

        self.assertTrue(-eighteen_hours < offset < eighteen_hours)