Extract grp/pwd handling to a unix_compat module.

Author: jaraco

distutils/tests/test_archive_util.py

@@ -14,16 +14,11 @@
 from distutils.spawn import find_executable, spawn
 from distutils.tests import support
 from test.support import run_unittest, patch
+from .unix_compat import require_unix_id, require_uid_0, grp, pwd, UID_0_SUPPORT
 
 from .py38compat import change_cwd
 from .py38compat import check_warnings
 
-try:
-    import grp
-    import pwd
-    UID_GID_SUPPORT = True
-except ImportError:
-    UID_GID_SUPPORT = False
 
 try:
     import zipfile
@@ -339,7 +334,7 @@ def test_make_archive_xztar(self):
     def test_make_archive_owner_group(self):
         # testing make_archive with owner and group, with various combinations
         # this works even if there's not gid/uid support
-        if UID_GID_SUPPORT and sys.platform != "cygwin":
+        if UID_0_SUPPORT:
             group = grp.getgrgid(0)[0]
             owner = pwd.getpwuid(0)[0]
         else:
@@ -364,8 +359,8 @@ def test_make_archive_owner_group(self):
         self.assertTrue(os.path.exists(res))
 
     @unittest.skipUnless(ZLIB_SUPPORT, "Requires zlib")
-    @unittest.skipUnless(UID_GID_SUPPORT, "Requires grp and pwd support")
-    @unittest.skipUnless(sys.platform != "cygwin", "Cygwin doesn't have UID=0")
+    @require_unix_id
+    @require_uid_0
     def test_tarfile_root_owner(self):
         tmpdir =  self._create_files()
         base_name = os.path.join(self.mkdtemp(), 'archive')

distutils/tests/test_sdist.py

@@ -1,13 +1,13 @@
 """Tests for distutils.command.sdist."""
 import os
-import sys
 import tarfile
 import unittest
 import warnings
 import zipfile
 from os.path import join
 from textwrap import dedent
 from test.support import captured_stdout, run_unittest
+from .unix_compat import require_unix_id, require_uid_0, pwd, grp
 
 from .py38compat import check_warnings
 
@@ -17,13 +17,6 @@
 except ImportError:
     ZLIB_SUPPORT = False
 
-try:
-    import grp
-    import pwd
-    UID_GID_SUPPORT = True
-except ImportError:
-    UID_GID_SUPPORT = False
-
 from distutils.command.sdist import sdist, show_formats
 from distutils.core import Distribution
 from distutils.tests.test_config import BasePyPIRCCommandTestCase
@@ -441,8 +434,8 @@ def test_manual_manifest(self):
                                              'fake-1.0/README.manual'])
 
     @unittest.skipUnless(ZLIB_SUPPORT, "requires zlib")
-    @unittest.skipUnless(UID_GID_SUPPORT, "Requires grp and pwd support")
-    @unittest.skipUnless(sys.platform != "cygwin", "Cygwin doesn't have UID=0")
+    @require_unix_id
+    @require_uid_0
     @unittest.skipIf(find_executable('tar') is None,
                      "The tar command is not found")
     @unittest.skipIf(find_executable('gzip') is None,

distutils/tests/unix_compat.py

@@ -0,0 +1,16 @@
+import sys
+import unittest
+
+try:
+    import grp
+    import pwd
+except ImportError:
+    grp = pwd = None
+
+
+UNIX_ID_SUPPORT = grp and pwd
+UID_0_SUPPORT = UNIX_ID_SUPPORT and sys.platform != "cygwin"
+
+require_unix_id = unittest.skipUnless(
+    UNIX_ID_SUPPORT, "Requires grp and pwd support")
+require_uid_0 = unittest.skipUnless(UID_0_SUPPORT, "Requires UID 0 support")