test_path.py

# encoding: utf-8
"""Tests for IPython.utils.path.py"""

# Copyright (c) IPython Development Team.
# Distributed under the terms of the Modified BSD License.

import errno
import os
import shutil
import sys
import tempfile
import warnings
from contextlib import contextmanager

try:  # Python 3.3+
    from unittest.mock import patch
except ImportError:
    from mock import patch

from os.path import join, abspath, split

from nose import SkipTest
import nose.tools as nt

from nose import with_setup

import IPython
from IPython.testing import decorators as dec
from IPython.testing.decorators import (skip_if_not_win32, skip_win32,
                                        onlyif_unicode_paths,)
from IPython.testing.tools import make_tempfile, AssertPrints
from IPython.utils import path
from IPython.utils import py3compat
from IPython.utils.tempdir import TemporaryDirectory

# Platform-dependent imports
try:
    import winreg as wreg  # Py 3
except ImportError:
    try:
        import _winreg as wreg  # Py 2
    except ImportError:
        #Fake _winreg module on none windows platforms
        import types
        wr_name = "winreg" if py3compat.PY3 else "_winreg"
        sys.modules[wr_name] = types.ModuleType(wr_name)
        try:
            import winreg as wreg
        except ImportError:
            import _winreg as wreg
        #Add entries that needs to be stubbed by the testing code
        (wreg.OpenKey, wreg.QueryValueEx,) = (None, None)

try:
    reload
except NameError:   # Python 3
    from imp import reload

#-----------------------------------------------------------------------------
# Globals
#-----------------------------------------------------------------------------
env = os.environ
TEST_FILE_PATH = split(abspath(__file__))[0]
TMP_TEST_DIR = tempfile.mkdtemp()
HOME_TEST_DIR = join(TMP_TEST_DIR, "home_test_dir")
XDG_TEST_DIR = join(HOME_TEST_DIR, "xdg_test_dir")
XDG_CACHE_DIR = join(HOME_TEST_DIR, "xdg_cache_dir")
IP_TEST_DIR = join(HOME_TEST_DIR,'.ipython')
#
# Setup/teardown functions/decorators
#

def setup():
    """Setup testenvironment for the module:

            - Adds dummy home dir tree
    """
    # Do not mask exceptions here.  In particular, catching WindowsError is a
    # problem because that exception is only defined on Windows...
    os.makedirs(IP_TEST_DIR)
    os.makedirs(os.path.join(XDG_TEST_DIR, 'ipython'))
    os.makedirs(os.path.join(XDG_CACHE_DIR, 'ipython'))


def teardown():
    """Teardown testenvironment for the module:

            - Remove dummy home dir tree
    """
    # Note: we remove the parent test dir, which is the root of all test
    # subdirs we may have created.  Use shutil instead of os.removedirs, so
    # that non-empty directories are all recursively removed.
    shutil.rmtree(TMP_TEST_DIR)


def setup_environment():
    """Setup testenvironment for some functions that are tested
    in this module. In particular this functions stores attributes
    and other things that we need to stub in some test functions.
    This needs to be done on a function level and not module level because
    each testfunction needs a pristine environment.
    """
    global oldstuff, platformstuff
    oldstuff = (env.copy(), os.name, sys.platform, path.get_home_dir, IPython.__file__, os.getcwd())

def teardown_environment():
    """Restore things that were remembered by the setup_environment function
    """
    (oldenv, os.name, sys.platform, path.get_home_dir, IPython.__file__, old_wd) = oldstuff
    os.chdir(old_wd)
    reload(path)

    for key in list(env):
        if key not in oldenv:
            del env[key]
    env.update(oldenv)
    if hasattr(sys, 'frozen'):
        del sys.frozen

# Build decorator that uses the setup_environment/setup_environment
with_environment = with_setup(setup_environment, teardown_environment)

@contextmanager
def patch_get_home_dir(dirpath):
    orig_get_home_dir = path.get_home_dir
    path.get_home_dir = lambda : dirpath
    try:
        yield
    finally:
        path.get_home_dir = orig_get_home_dir

@skip_if_not_win32
@with_environment
def test_get_home_dir_1():
    """Testcase for py2exe logic, un-compressed lib
    """
    unfrozen = path.get_home_dir()
    sys.frozen = True

    #fake filename for IPython.__init__
    IPython.__file__ = abspath(join(HOME_TEST_DIR, "Lib/IPython/__init__.py"))

    home_dir = path.get_home_dir()
    nt.assert_equal(home_dir, unfrozen)


@skip_if_not_win32
@with_environment
def test_get_home_dir_2():
    """Testcase for py2exe logic, compressed lib
    """
    unfrozen = path.get_home_dir()
    sys.frozen = True
    #fake filename for IPython.__init__
    IPython.__file__ = abspath(join(HOME_TEST_DIR, "Library.zip/IPython/__init__.py")).lower()

    home_dir = path.get_home_dir(True)
    nt.assert_equal(home_dir, unfrozen)


@with_environment
def test_get_home_dir_3():
    """get_home_dir() uses $HOME if set"""
    env["HOME"] = HOME_TEST_DIR
    home_dir = path.get_home_dir(True)
    # get_home_dir expands symlinks
    nt.assert_equal(home_dir, os.path.realpath(env["HOME"]))


@with_environment
def test_get_home_dir_4():
    """get_home_dir() still works if $HOME is not set"""

    if 'HOME' in env: del env['HOME']
    # this should still succeed, but we don't care what the answer is
    home = path.get_home_dir(False)

@with_environment
def test_get_home_dir_5():
    """raise HomeDirError if $HOME is specified, but not a writable dir"""
    env['HOME'] = abspath(HOME_TEST_DIR+'garbage')
    # set os.name = posix, to prevent My Documents fallback on Windows
    os.name = 'posix'
    nt.assert_raises(path.HomeDirError, path.get_home_dir, True)

# Should we stub wreg fully so we can run the test on all platforms?
@skip_if_not_win32
@with_environment
def test_get_home_dir_8():
    """Using registry hack for 'My Documents', os=='nt'

    HOMESHARE, HOMEDRIVE, HOMEPATH, USERPROFILE and others are missing.
    """
    os.name = 'nt'
    # Remove from stub environment all keys that may be set
    for key in ['HOME', 'HOMESHARE', 'HOMEDRIVE', 'HOMEPATH', 'USERPROFILE']:
        env.pop(key, None)

    class key:
        def Close(self):
            pass

    with patch.object(wreg, 'OpenKey', return_value=key()), \
         patch.object(wreg, 'QueryValueEx', return_value=[abspath(HOME_TEST_DIR)]):
        home_dir = path.get_home_dir()
    nt.assert_equal(home_dir, abspath(HOME_TEST_DIR))


@with_environment
def test_get_ipython_dir_1():
    """test_get_ipython_dir_1, Testcase to see if we can call get_ipython_dir without Exceptions."""
    env_ipdir = os.path.join("someplace", ".ipython")
    path._writable_dir = lambda path: True
    env['IPYTHONDIR'] = env_ipdir
    ipdir = path.get_ipython_dir()
    nt.assert_equal(ipdir, env_ipdir)


@with_environment
def test_get_ipython_dir_2():
    """test_get_ipython_dir_2, Testcase to see if we can call get_ipython_dir without Exceptions."""
    with patch_get_home_dir('someplace'):
        path.get_xdg_dir = lambda : None
        path._writable_dir = lambda path: True
        os.name = "posix"
        env.pop('IPYTHON_DIR', None)
        env.pop('IPYTHONDIR', None)
        env.pop('XDG_CONFIG_HOME', None)
        ipdir = path.get_ipython_dir()
        nt.assert_equal(ipdir, os.path.join("someplace", ".ipython"))

@with_environment
def test_get_ipython_dir_3():
    """test_get_ipython_dir_3, move XDG if defined, and .ipython doesn't exist."""
    tmphome = TemporaryDirectory()
    try:
        with patch_get_home_dir(tmphome.name):
            os.name = "posix"
            env.pop('IPYTHON_DIR', None)
            env.pop('IPYTHONDIR', None)
            env['XDG_CONFIG_HOME'] = XDG_TEST_DIR

            with warnings.catch_warnings(record=True) as w:
                ipdir = path.get_ipython_dir()

            nt.assert_equal(ipdir, os.path.join(tmphome.name, ".ipython"))
            if sys.platform != 'darwin':
                nt.assert_equal(len(w), 1)
                nt.assert_in('Moving', str(w[0]))
    finally:
        tmphome.cleanup()

@with_environment
def test_get_ipython_dir_4():
    """test_get_ipython_dir_4, warn if XDG and home both exist."""
    with patch_get_home_dir(HOME_TEST_DIR):
        os.name = "posix"
        env.pop('IPYTHON_DIR', None)
        env.pop('IPYTHONDIR', None)
        env['XDG_CONFIG_HOME'] = XDG_TEST_DIR
        try:
            os.mkdir(os.path.join(XDG_TEST_DIR, 'ipython'))
        except OSError as e:
            if e.errno != errno.EEXIST:
                raise

        with warnings.catch_warnings(record=True) as w:
            ipdir = path.get_ipython_dir()

        nt.assert_equal(ipdir, os.path.join(HOME_TEST_DIR, ".ipython"))
        if sys.platform != 'darwin':
            nt.assert_equal(len(w), 1)
            nt.assert_in('Ignoring', str(w[0]))

@with_environment
def test_get_ipython_dir_5():
    """test_get_ipython_dir_5, use .ipython if exists and XDG defined, but doesn't exist."""
    with patch_get_home_dir(HOME_TEST_DIR):
        os.name = "posix"
        env.pop('IPYTHON_DIR', None)
        env.pop('IPYTHONDIR', None)
        env['XDG_CONFIG_HOME'] = XDG_TEST_DIR
        try:
            os.rmdir(os.path.join(XDG_TEST_DIR, 'ipython'))
        except OSError as e:
            if e.errno != errno.ENOENT:
                raise
        ipdir = path.get_ipython_dir()
        nt.assert_equal(ipdir, IP_TEST_DIR)

@with_environment
def test_get_ipython_dir_6():
    """test_get_ipython_dir_6, use home over XDG if defined and neither exist."""
    xdg = os.path.join(HOME_TEST_DIR, 'somexdg')
    os.mkdir(xdg)
    shutil.rmtree(os.path.join(HOME_TEST_DIR, '.ipython'))
    with patch_get_home_dir(HOME_TEST_DIR):
        orig_get_xdg_dir = path.get_xdg_dir
        path.get_xdg_dir = lambda : xdg
        try:
            os.name = "posix"
            env.pop('IPYTHON_DIR', None)
            env.pop('IPYTHONDIR', None)
            env.pop('XDG_CONFIG_HOME', None)
            with warnings.catch_warnings(record=True) as w:
                ipdir = path.get_ipython_dir()

            nt.assert_equal(ipdir, os.path.join(HOME_TEST_DIR, '.ipython'))
            nt.assert_equal(len(w), 0)
        finally:
            path.get_xdg_dir = orig_get_xdg_dir

@with_environment
def test_get_ipython_dir_7():
    """test_get_ipython_dir_7, test home directory expansion on IPYTHONDIR"""
    path._writable_dir = lambda path: True
    home_dir = os.path.normpath(os.path.expanduser('~'))
    env['IPYTHONDIR'] = os.path.join('~', 'somewhere')
    ipdir = path.get_ipython_dir()
    nt.assert_equal(ipdir, os.path.join(home_dir, 'somewhere'))

@skip_win32
@with_environment
def test_get_ipython_dir_8():
    """test_get_ipython_dir_8, test / home directory"""
    old = path._writable_dir, path.get_xdg_dir
    try:
        path._writable_dir = lambda path: bool(path)
        path.get_xdg_dir = lambda: None
        env.pop('IPYTHON_DIR', None)
        env.pop('IPYTHONDIR', None)
        env['HOME'] = '/'
        nt.assert_equal(path.get_ipython_dir(), '/.ipython')
    finally:
        path._writable_dir, path.get_xdg_dir = old

@with_environment
def test_get_xdg_dir_0():
    """test_get_xdg_dir_0, check xdg_dir"""
    reload(path)
    path._writable_dir = lambda path: True
    path.get_home_dir = lambda : 'somewhere'
    os.name = "posix"
    sys.platform = "linux2"
    env.pop('IPYTHON_DIR', None)
    env.pop('IPYTHONDIR', None)
    env.pop('XDG_CONFIG_HOME', None)

    nt.assert_equal(path.get_xdg_dir(), os.path.join('somewhere', '.config'))


@with_environment
def test_get_xdg_dir_1():
    """test_get_xdg_dir_1, check nonexistant xdg_dir"""
    reload(path)
    path.get_home_dir = lambda : HOME_TEST_DIR
    os.name = "posix"
    sys.platform = "linux2"
    env.pop('IPYTHON_DIR', None)
    env.pop('IPYTHONDIR', None)
    env.pop('XDG_CONFIG_HOME', None)
    nt.assert_equal(path.get_xdg_dir(), None)

@with_environment
def test_get_xdg_dir_2():
    """test_get_xdg_dir_2, check xdg_dir default to ~/.config"""
    reload(path)
    path.get_home_dir = lambda : HOME_TEST_DIR
    os.name = "posix"
    sys.platform = "linux2"
    env.pop('IPYTHON_DIR', None)
    env.pop('IPYTHONDIR', None)
    env.pop('XDG_CONFIG_HOME', None)
    cfgdir=os.path.join(path.get_home_dir(), '.config')
    if not os.path.exists(cfgdir):
        os.makedirs(cfgdir)

    nt.assert_equal(path.get_xdg_dir(), cfgdir)

@with_environment
def test_get_xdg_dir_3():
    """test_get_xdg_dir_3, check xdg_dir not used on OS X"""
    reload(path)
    path.get_home_dir = lambda : HOME_TEST_DIR
    os.name = "posix"
    sys.platform = "darwin"
    env.pop('IPYTHON_DIR', None)
    env.pop('IPYTHONDIR', None)
    env.pop('XDG_CONFIG_HOME', None)
    cfgdir=os.path.join(path.get_home_dir(), '.config')
    if not os.path.exists(cfgdir):
        os.makedirs(cfgdir)

    nt.assert_equal(path.get_xdg_dir(), None)

def test_filefind():
    """Various tests for filefind"""
    f = tempfile.NamedTemporaryFile()
    # print 'fname:',f.name
    alt_dirs = path.get_ipython_dir()
    t = path.filefind(f.name, alt_dirs)
    # print 'found:',t

@with_environment
def test_get_ipython_cache_dir():
    os.environ["HOME"] = HOME_TEST_DIR
    if os.name == 'posix' and sys.platform != 'darwin':
        # test default
        os.makedirs(os.path.join(HOME_TEST_DIR, ".cache"))
        os.environ.pop("XDG_CACHE_HOME", None)
        ipdir = path.get_ipython_cache_dir()
        nt.assert_equal(os.path.join(HOME_TEST_DIR, ".cache", "ipython"),
                        ipdir)
        nt.assert_true(os.path.isdir(ipdir))

        # test env override
        os.environ["XDG_CACHE_HOME"] = XDG_CACHE_DIR
        ipdir = path.get_ipython_cache_dir()
        nt.assert_true(os.path.isdir(ipdir))
        nt.assert_equal(ipdir, os.path.join(XDG_CACHE_DIR, "ipython"))
    else:
        nt.assert_equal(path.get_ipython_cache_dir(),
                        path.get_ipython_dir())

def test_get_ipython_package_dir():
    ipdir = path.get_ipython_package_dir()
    nt.assert_true(os.path.isdir(ipdir))


def test_get_ipython_module_path():
    ipapp_path = path.get_ipython_module_path('IPython.terminal.ipapp')
    nt.assert_true(os.path.isfile(ipapp_path))


@dec.skip_if_not_win32
def test_get_long_path_name_win32():
    with TemporaryDirectory() as tmpdir:

        # Make a long path. Expands the path of tmpdir prematurely as it may already have a long 
        # path component, so ensure we include the long form of it
        long_path = os.path.join(path.get_long_path_name(tmpdir), u'this is my long path name')
        os.makedirs(long_path)

        # Test to see if the short path evaluates correctly.
        short_path = os.path.join(tmpdir, u'THISIS~1')
        evaluated_path = path.get_long_path_name(short_path)
        nt.assert_equal(evaluated_path.lower(), long_path.lower())


@dec.skip_win32
def test_get_long_path_name():
    p = path.get_long_path_name('/usr/local')
    nt.assert_equal(p,'/usr/local')

@dec.skip_win32 # can't create not-user-writable dir on win
@with_environment
def test_not_writable_ipdir():
    tmpdir = tempfile.mkdtemp()
    os.name = "posix"
    env.pop('IPYTHON_DIR', None)
    env.pop('IPYTHONDIR', None)
    env.pop('XDG_CONFIG_HOME', None)
    env['HOME'] = tmpdir
    ipdir = os.path.join(tmpdir, '.ipython')
    os.mkdir(ipdir, 0o555)
    try:
        open(os.path.join(ipdir, "_foo_"), 'w').close()
    except IOError:
        pass
    else:
        # I can still write to an unwritable dir,
        # assume I'm root and skip the test
        raise SkipTest("I can't create directories that I can't write to")
    with AssertPrints('is not a writable location', channel='stderr'):
        ipdir = path.get_ipython_dir()
    env.pop('IPYTHON_DIR', None)

def test_unquote_filename():
    for win32 in (True, False):
        nt.assert_equal(path.unquote_filename('foo.py', win32=win32), 'foo.py')
        nt.assert_equal(path.unquote_filename('foo bar.py', win32=win32), 'foo bar.py')
    nt.assert_equal(path.unquote_filename('"foo.py"', win32=True), 'foo.py')
    nt.assert_equal(path.unquote_filename('"foo bar.py"', win32=True), 'foo bar.py')
    nt.assert_equal(path.unquote_filename("'foo.py'", win32=True), 'foo.py')
    nt.assert_equal(path.unquote_filename("'foo bar.py'", win32=True), 'foo bar.py')
    nt.assert_equal(path.unquote_filename('"foo.py"', win32=False), '"foo.py"')
    nt.assert_equal(path.unquote_filename('"foo bar.py"', win32=False), '"foo bar.py"')
    nt.assert_equal(path.unquote_filename("'foo.py'", win32=False), "'foo.py'")
    nt.assert_equal(path.unquote_filename("'foo bar.py'", win32=False), "'foo bar.py'")

@with_environment
def test_get_py_filename():
    os.chdir(TMP_TEST_DIR)
    for win32 in (True, False):
        with make_tempfile('foo.py'):
            nt.assert_equal(path.get_py_filename('foo.py', force_win32=win32), 'foo.py')
            nt.assert_equal(path.get_py_filename('foo', force_win32=win32), 'foo.py')
        with make_tempfile('foo'):
            nt.assert_equal(path.get_py_filename('foo', force_win32=win32), 'foo')
            nt.assert_raises(IOError, path.get_py_filename, 'foo.py', force_win32=win32)
        nt.assert_raises(IOError, path.get_py_filename, 'foo', force_win32=win32)
        nt.assert_raises(IOError, path.get_py_filename, 'foo.py', force_win32=win32)
        true_fn = 'foo with spaces.py'
        with make_tempfile(true_fn):
            nt.assert_equal(path.get_py_filename('foo with spaces', force_win32=win32), true_fn)
            nt.assert_equal(path.get_py_filename('foo with spaces.py', force_win32=win32), true_fn)
            if win32:
                nt.assert_equal(path.get_py_filename('"foo with spaces.py"', force_win32=True), true_fn)
                nt.assert_equal(path.get_py_filename("'foo with spaces.py'", force_win32=True), true_fn)
            else:
                nt.assert_raises(IOError, path.get_py_filename, '"foo with spaces.py"', force_win32=False)
                nt.assert_raises(IOError, path.get_py_filename, "'foo with spaces.py'", force_win32=False)

@onlyif_unicode_paths
def test_unicode_in_filename():
    """When a file doesn't exist, the exception raised should be safe to call
    str() on - i.e. in Python 2 it must only have ASCII characters.
    
    https://github.com/ipython/ipython/issues/875
    """
    try:
        # these calls should not throw unicode encode exceptions
        path.get_py_filename(u'fooéè.py',  force_win32=False)
    except IOError as ex:
        str(ex)


class TestShellGlob(object):

    @classmethod
    def setUpClass(cls):
        cls.filenames_start_with_a = ['a0', 'a1', 'a2']
        cls.filenames_end_with_b = ['0b', '1b', '2b']
        cls.filenames = cls.filenames_start_with_a + cls.filenames_end_with_b
        cls.tempdir = TemporaryDirectory()
        td = cls.tempdir.name

        with cls.in_tempdir():
            # Create empty files
            for fname in cls.filenames:
                open(os.path.join(td, fname), 'w').close()

    @classmethod
    def tearDownClass(cls):
        cls.tempdir.cleanup()

    @classmethod
    @contextmanager
    def in_tempdir(cls):
        save = py3compat.getcwd()
        try:
            os.chdir(cls.tempdir.name)
            yield
        finally:
            os.chdir(save)

    def check_match(self, patterns, matches):
        with self.in_tempdir():
            # glob returns unordered list. that's why sorted is required.
            nt.assert_equals(sorted(path.shellglob(patterns)),
                             sorted(matches))

    def common_cases(self):
        return [
            (['*'], self.filenames),
            (['a*'], self.filenames_start_with_a),
            (['*c'], ['*c']),
            (['*', 'a*', '*b', '*c'], self.filenames
                                      + self.filenames_start_with_a
                                      + self.filenames_end_with_b
                                      + ['*c']),
            (['a[012]'], self.filenames_start_with_a),
        ]

    @skip_win32
    def test_match_posix(self):
        for (patterns, matches) in self.common_cases() + [
                ([r'\*'], ['*']),
                ([r'a\*', 'a*'], ['a*'] + self.filenames_start_with_a),
                ([r'a\[012]'], ['a[012]']),
                ]:
            yield (self.check_match, patterns, matches)

    @skip_if_not_win32
    def test_match_windows(self):
        for (patterns, matches) in self.common_cases() + [
                # In windows, backslash is interpreted as path
                # separator.  Therefore, you can't escape glob
                # using it.
                ([r'a\*', 'a*'], [r'a\*'] + self.filenames_start_with_a),
                ([r'a\[012]'], [r'a\[012]']),
                ]:
            yield (self.check_match, patterns, matches)


def test_unescape_glob():
    nt.assert_equals(path.unescape_glob(r'\*\[\!\]\?'), '*[!]?')
    nt.assert_equals(path.unescape_glob(r'\\*'), r'\*')
    nt.assert_equals(path.unescape_glob(r'\\\*'), r'\*')
    nt.assert_equals(path.unescape_glob(r'\\a'), r'\a')
    nt.assert_equals(path.unescape_glob(r'\a'), r'\a')


def test_ensure_dir_exists():
    with TemporaryDirectory() as td:
        d = os.path.join(td, u'∂ir')
        path.ensure_dir_exists(d) # create it
        assert os.path.isdir(d)
        path.ensure_dir_exists(d) # no-op
        f = os.path.join(td, u'ƒile')
        open(f, 'w').close() # touch
        with nt.assert_raises(IOError):
            path.ensure_dir_exists(f)

class TestLinkOrCopy(object):
    def setUp(self):
        self.tempdir = TemporaryDirectory()
        self.src = self.dst("src")
        with open(self.src, "w") as f:
            f.write("Hello, world!")

    def tearDown(self):
        self.tempdir.cleanup()

    def dst(self, *args):
        return os.path.join(self.tempdir.name, *args)

    def assert_inode_not_equal(self, a, b):
        nt.assert_not_equals(os.stat(a).st_ino, os.stat(b).st_ino,
                             "%r and %r do reference the same indoes" %(a, b))

    def assert_inode_equal(self, a, b):
        nt.assert_equals(os.stat(a).st_ino, os.stat(b).st_ino,
                         "%r and %r do not reference the same indoes" %(a, b))

    def assert_content_equal(self, a, b):
        with open(a) as a_f:
            with open(b) as b_f:
                nt.assert_equals(a_f.read(), b_f.read())

    @skip_win32
    def test_link_successful(self):
        dst = self.dst("target")
        path.link_or_copy(self.src, dst)
        self.assert_inode_equal(self.src, dst)

    @skip_win32
    def test_link_into_dir(self):
        dst = self.dst("some_dir")
        os.mkdir(dst)
        path.link_or_copy(self.src, dst)
        expected_dst = self.dst("some_dir", os.path.basename(self.src))
        self.assert_inode_equal(self.src, expected_dst)

    @skip_win32
    def test_target_exists(self):
        dst = self.dst("target")
        open(dst, "w").close()
        path.link_or_copy(self.src, dst)
        self.assert_inode_equal(self.src, dst)

    @skip_win32
    def test_no_link(self):
        real_link = os.link
        try:
            del os.link
            dst = self.dst("target")
            path.link_or_copy(self.src, dst)
            self.assert_content_equal(self.src, dst)
            self.assert_inode_not_equal(self.src, dst)
        finally:
            os.link = real_link

    @skip_if_not_win32
    def test_windows(self):
        dst = self.dst("target")
        path.link_or_copy(self.src, dst)
        self.assert_content_equal(self.src, dst)

    def test_link_twice(self):
        # Linking the same file twice shouldn't leave duplicates around.
        # See https://github.com/ipython/ipython/issues/6450
        dst = self.dst('target')
        path.link_or_copy(self.src, dst)
        path.link_or_copy(self.src, dst)
        self.assert_inode_equal(self.src, dst)
        nt.assert_equal(sorted(os.listdir(self.tempdir.name)), ['src', 'target'])