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"""Tests for file IO"""
# Copyright (c) Jupyter Development Team.
# Distributed under the terms of the Modified BSD License.
import os.path
import unittest
import pytest
import stat
import sys
from ..fileio import atomic_writing
from ipython_genutils.tempdir import TemporaryDirectory
umask = 0
def test_atomic_writing():
class CustomExc(Exception):
pass
with TemporaryDirectory() as td:
f1 = os.path.join(td, 'penguin')
with open(f1, 'w') as f:
f.write('Before')
if os.name != 'nt':
os.chmod(f1, 0o701)
orig_mode = stat.S_IMODE(os.stat(f1).st_mode)
f2 = os.path.join(td, 'flamingo')
try:
os.symlink(f1, f2)
have_symlink = True
except (AttributeError, NotImplementedError, OSError):
# AttributeError: Python doesn't support it
# NotImplementedError: The system doesn't support it
# OSError: The user lacks the privilege (Windows)
have_symlink = False
with pytest.raises(CustomExc):
with atomic_writing(f1) as f:
f.write('Failing write')
raise CustomExc
# Because of the exception, the file should not have been modified
with open(f1) as f:
assert f.read() == 'Before'
with atomic_writing(f1) as f:
f.write('Overwritten')
with open(f1) as f:
assert f.read() == 'Overwritten'
if os.name != 'nt':
mode = stat.S_IMODE(os.stat(f1).st_mode)
assert mode == orig_mode
if have_symlink:
# Check that writing over a file preserves a symlink
with atomic_writing(f2) as f:
f.write('written from symlink')
with open(f1) as f:
assert f.read() == 'written from symlink'
class TestWithSetUmask(unittest.TestCase):
def setUp(self):
# save umask
global umask
umask = os.umask(0)
os.umask(umask)
def tearDown(self):
# restore umask
os.umask(umask)
@pytest.mark.skipif(sys.platform == "win32", reason="do not run on windows")
def test_atomic_writing_umask(self):
with TemporaryDirectory() as td:
os.umask(0o022)
f1 = os.path.join(td, '1')
with atomic_writing(f1) as f:
f.write('1')
mode = stat.S_IMODE(os.stat(f1).st_mode)
assert mode == 0o644
os.umask(0o057)
f2 = os.path.join(td, '2')
with atomic_writing(f2) as f:
f.write('2')
mode = stat.S_IMODE(os.stat(f2).st_mode)
assert mode == 0o620
def test_atomic_writing_newlines():
with TemporaryDirectory() as td:
path = os.path.join(td, 'testfile')
lf = 'a\nb\nc\n'
plat = lf.replace('\n', os.linesep)
crlf = lf.replace('\n', '\r\n')
# test default
with open(path, 'w') as f:
f.write(lf)
with open(path, newline='') as f:
read = f.read()
assert read == plat
# test newline=LF
with open(path, 'w', newline='\n') as f:
f.write(lf)
with open(path, newline='') as f:
read = f.read()
assert read == lf
# test newline=CRLF
with atomic_writing(path, newline='\r\n') as f:
f.write(lf)
with open(path, newline='') as f:
read = f.read()
assert read == crlf
# test newline=no convert
text = 'crlf\r\ncr\rlf\n'
with atomic_writing(path, newline='') as f:
f.write(text)
with open(path, newline='') as f:
read = f.read()
assert read == text
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