Add a work-around for cleaning up temporary directories. Needed for Python 3.7 on Windows.

CHANGES.rst

@@ -11,13 +11,14 @@ Added
 - Black's ``target-version =`` configuration file option and ``-t`` /
  ``--target-version`` command line option
 
-
 Fixed
 -----
 - Compatibility of highlighting unit tests with Pygments 2.14.0.
 - In the CI test workflow, don't use environment variables to add a Black version
  constraint to the ``pip`` command. This fixes the Windows builds.
 - Pass Git errors to stderr correctly both in raw and encoded subprocess output mode.
+- Add a work-around for cleaning up temporary directories. Needed for Python 3.7 on
+ Windows.
 
 
 1.6.1_ - 2022-12-28

src/darker/tests/conftest.py

@@ -10,6 +10,7 @@
 from black import find_project_root as black_find_project_root
 
 from darker.git import _git_check_output_lines, git_get_version
+from darker.utils import fix_py37_win_tempdir_permissions
 
 
 class GitRepoFixture:
@@ -114,7 +115,10 @@ def git_repo(tmp_path, monkeypatch):
  # variables for any Git commands run by the fixture, let's explicitly remove
  # `GIT_DIR` in case a test should call Git directly:
  monkeypatch.delenv("GIT_DIR", raising=False)
- return repository
+
+ yield repository
+
+ fix_py37_win_tempdir_permissions(repository.root)
 
 
 @pytest.fixture

src/darker/tests/test_linting.py

@@ -3,7 +3,6 @@
 """Unit tests for :mod:`darker.linting`"""
 
 import os
-import sys
 from pathlib import Path
 from textwrap import dedent
 from unittest.mock import call, patch
@@ -13,9 +12,10 @@
 from darker import linting
 from darker.git import WORKTREE, RevisionRange
 from darker.tests.helpers import raises_if_exception
+from darker.utils import WINDOWS
 
-SKIP_ON_WINDOWS = [pytest.mark.skip] if sys.platform.startswith("win") else []
-SKIP_ON_UNIX = [] if sys.platform.startswith("win") else [pytest.mark.skip]
+SKIP_ON_WINDOWS = [pytest.mark.skip] if WINDOWS else []
+SKIP_ON_UNIX = [] if WINDOWS else [pytest.mark.skip]
 
 
 @pytest.mark.kwparametrize(

src/darker/utils.py

@@ -2,17 +2,20 @@
 
 import io
 import logging
+import os
+import sys
 import tokenize
 from datetime import datetime
 from itertools import chain
 from pathlib import Path
-from typing import Collection, Iterable, List, Tuple
+from typing import Collection, Iterable, List, Tuple, Union
 
 logger = logging.getLogger(__name__)
 
 TextLines = Tuple[str, ...]
 
 
+WINDOWS = sys.platform.startswith("win")
 GIT_DATEFORMAT = "%Y-%m-%d %H:%M:%S.%f +0000"
 
 
@@ -237,3 +240,27 @@ def glob_any(path: Path, patterns: Collection[str]) -> bool:
 
  """
  return any(path.glob(pattern) for pattern in patterns)
+
+
+def fix_py37_win_tempdir_permissions(dirpath: Union[str, Path]) -> None:
+ """Work around a `tempfile` clean-up issue on Windows with Python 3.7
+
+ Call this before exiting a ``with TemporaryDirectory():`` block or in teardown for
+ a Pytest fixture which creates a temporary directory.
+
+ See discussion in https://github.com/akaihola/darker/pull/393
+ Solution borrowed from https://github.com/python/cpython/pull/10320
+
+ :param dirpath: The root path of the temporary directory
+
+ """
+ if not WINDOWS or sys.version_info >= (3, 8):
+ return
+ for root, dirs, files in os.walk(dirpath):
+ for name in dirs + files:
+ path = os.path.join(root, name)
+ try:
+ os.chflags(path, 0) # type: ignore[attr-defined]
+ except AttributeError:
+ pass
+ os.chmod(path, 0o700)