bpo-40275: Use new test.support helper submodules in tests (GH-21151)

Use new test.support helper submodules in tests:

* distutils tests
* test_buffer
* test_compile
* test_filecmp
* test_fileinput
* test_readline
* test_smtpnet
* test_structmembers
* test_tools

8 files changed, 38 insertions, 26 deletions

diff --git a/Lib/test/test_buffer.py b/Lib/test/test_buffer.py
index d440bcf..468c6ea 100644
--- a/Lib/test/test_buffer.py
+++ b/Lib/test/test_buffer.py
@@ -16,6 +16,7 @@
 import contextlib
 import unittest
 from test import support
+from test.support import os_helper
 from itertools import permutations, product
 from random import randrange, sample, choice
 import warnings
@@ -39,7 +40,7 @@ except ImportError:
     ctypes = None
 
 try:
-    with support.EnvironmentVarGuard() as os.environ, \
+    with os_helper.EnvironmentVarGuard() as os.environ, \
          warnings.catch_warnings():
         from numpy import ndarray as numpy_array
 except ImportError:
diff --git a/Lib/test/test_compile.py b/Lib/test/test_compile.py
index 566ca27..3dd8c8d 100644
--- a/Lib/test/test_compile.py
+++ b/Lib/test/test_compile.py
@@ -7,7 +7,9 @@ import _ast
 import tempfile
 import types
 from test import support
-from test.support import script_helper, FakePath
+from test.support import script_helper
+from test.support.os_helper import FakePath
+
 
 class TestSpecifics(unittest.TestCase):
 
diff --git a/Lib/test/test_filecmp.py b/Lib/test/test_filecmp.py
index b5b24a2..ca9b4f3 100644
--- a/Lib/test/test_filecmp.py
+++ b/Lib/test/test_filecmp.py
@@ -5,13 +5,14 @@ import tempfile
 import unittest
 
 from test import support
+from test.support import os_helper
 
 
 class FileCompareTestCase(unittest.TestCase):
     def setUp(self):
-        self.name = support.TESTFN
-        self.name_same = support.TESTFN + '-same'
-        self.name_diff = support.TESTFN + '-diff'
+        self.name = os_helper.TESTFN
+        self.name_same = os_helper.TESTFN + '-same'
+        self.name_diff = os_helper.TESTFN + '-diff'
         data = 'Contents of file go here.\n'
         for name in [self.name, self.name_same, self.name_diff]:
             with open(name, 'w') as output:
diff --git a/Lib/test/test_fileinput.py b/Lib/test/test_fileinput.py
index 014f19e..d5edf74 100644
--- a/Lib/test/test_fileinput.py
+++ b/Lib/test/test_fileinput.py
@@ -24,8 +24,11 @@ from io import BytesIO, StringIO
 from fileinput import FileInput, hook_encoded
 from pathlib import Path
 
-from test.support import verbose, TESTFN, check_warnings
-from test.support import unlink as safe_unlink
+from test.support import verbose
+from test.support.os_helper import TESTFN
+from test.support.os_helper import unlink as safe_unlink
+from test.support import os_helper
+from test.support import warnings_helper
 from test import support
 from unittest import mock
 
@@ -39,7 +42,7 @@ class BaseTests:
     # temp file's name.
     def writeTmp(self, content, *, mode='w'):  # opening in text mode is the default
         fd, name = tempfile.mkstemp()
-        self.addCleanup(support.unlink, name)
+        self.addCleanup(os_helper.unlink, name)
         with open(fd, mode) as f:
             f.write(content)
         return name
@@ -234,9 +237,9 @@ class FileInputTests(BaseTests, unittest.TestCase):
             pass
         # try opening in universal newline mode
         t1 = self.writeTmp(b"A\nB\r\nC\rD", mode="wb")
-        with check_warnings(('', DeprecationWarning)):
+        with warnings_helper.check_warnings(('', DeprecationWarning)):
             fi = FileInput(files=t1, mode="U")
-        with check_warnings(('', DeprecationWarning)):
+        with warnings_helper.check_warnings(('', DeprecationWarning)):
             lines = list(fi)
         self.assertEqual(lines, ["A\n", "B\n", "C\n", "D"])
 
@@ -353,7 +356,7 @@ class FileInputTests(BaseTests, unittest.TestCase):
         with FileInput(files=[]) as fi:
             self.assertEqual(fi._files, ('-',))
 
-    @support.ignore_warnings(category=DeprecationWarning)
+    @warnings_helper.ignore_warnings(category=DeprecationWarning)
     def test__getitem__(self):
         """Tests invoking FileInput.__getitem__() with the current
            line number"""
@@ -371,7 +374,7 @@ class FileInputTests(BaseTests, unittest.TestCase):
             with FileInput(files=[t]) as fi:
                 self.assertEqual(fi[0], "line1\n")
 
-    @support.ignore_warnings(category=DeprecationWarning)
+    @warnings_helper.ignore_warnings(category=DeprecationWarning)
     def test__getitem__invalid_key(self):
         """Tests invoking FileInput.__getitem__() with an index unequal to
            the line number"""
@@ -381,7 +384,7 @@ class FileInputTests(BaseTests, unittest.TestCase):
                 fi[1]
         self.assertEqual(cm.exception.args, ("accessing lines out of order",))
 
-    @support.ignore_warnings(category=DeprecationWarning)
+    @warnings_helper.ignore_warnings(category=DeprecationWarning)
     def test__getitem__eof(self):
         """Tests invoking FileInput.__getitem__() with the line number but at
            end-of-input"""
@@ -400,7 +403,7 @@ class FileInputTests(BaseTests, unittest.TestCase):
         os_unlink_replacement = UnconditionallyRaise(OSError)
         try:
             t = self.writeTmp("\n")
-            self.addCleanup(support.unlink, t + '.bak')
+            self.addCleanup(safe_unlink, t + '.bak')
             with FileInput(files=[t], inplace=True) as fi:
                 next(fi) # make sure the file is opened
                 os.unlink = os_unlink_replacement
diff --git a/Lib/test/test_readline.py b/Lib/test/test_readline.py
index 67ee9b7..de573be 100644
--- a/Lib/test/test_readline.py
+++ b/Lib/test/test_readline.py
@@ -10,7 +10,9 @@ import subprocess
 import sys
 import tempfile
 import unittest
-from test.support import import_module, unlink, temp_dir, TESTFN, verbose
+from test.support import verbose
+from test.support.import_helper import import_module
+from test.support.os_helper import unlink, temp_dir, TESTFN
 from test.support.script_helper import assert_python_ok
 
 # Skip tests if there is no readline module
diff --git a/Lib/test/test_smtpnet.py b/Lib/test/test_smtpnet.py
index 74a00a9..72f51cd 100644
--- a/Lib/test/test_smtpnet.py
+++ b/Lib/test/test_smtpnet.py
@@ -1,10 +1,11 @@
 import unittest
 from test import support
+from test.support import import_helper
 from test.support import socket_helper
 import smtplib
 import socket
 
-ssl = support.import_module("ssl")
+ssl = import_helper.import_module("ssl")
 
 support.requires("network")
 
diff --git a/Lib/test/test_structmembers.py b/Lib/test/test_structmembers.py
index 57ec45f..07d2f62 100644
--- a/Lib/test/test_structmembers.py
+++ b/Lib/test/test_structmembers.py
@@ -1,8 +1,9 @@
 import unittest
-from test import support
+from test.support import import_helper
+from test.support import warnings_helper
 
 # Skip this test if the _testcapi module isn't available.
-support.import_module('_testcapi')
+import_helper.import_module('_testcapi')
 from _testcapi import _test_structmembersType, \
     CHAR_MAX, CHAR_MIN, UCHAR_MAX, \
     SHRT_MAX, SHRT_MIN, USHRT_MAX, \
@@ -116,27 +117,27 @@ class ReadWriteTests(unittest.TestCase):
 class TestWarnings(unittest.TestCase):
 
     def test_byte_max(self):
-        with support.check_warnings(('', RuntimeWarning)):
+        with warnings_helper.check_warnings(('', RuntimeWarning)):
             ts.T_BYTE = CHAR_MAX+1
 
     def test_byte_min(self):
-        with support.check_warnings(('', RuntimeWarning)):
+        with warnings_helper.check_warnings(('', RuntimeWarning)):
             ts.T_BYTE = CHAR_MIN-1
 
     def test_ubyte_max(self):
-        with support.check_warnings(('', RuntimeWarning)):
+        with warnings_helper.check_warnings(('', RuntimeWarning)):
             ts.T_UBYTE = UCHAR_MAX+1
 
     def test_short_max(self):
-        with support.check_warnings(('', RuntimeWarning)):
+        with warnings_helper.check_warnings(('', RuntimeWarning)):
             ts.T_SHORT = SHRT_MAX+1
 
     def test_short_min(self):
-        with support.check_warnings(('', RuntimeWarning)):
+        with warnings_helper.check_warnings(('', RuntimeWarning)):
             ts.T_SHORT = SHRT_MIN-1
 
     def test_ushort_max(self):
-        with support.check_warnings(('', RuntimeWarning)):
+        with warnings_helper.check_warnings(('', RuntimeWarning)):
             ts.T_USHORT = USHRT_MAX+1
 
 
diff --git a/Lib/test/test_tools/__init__.py b/Lib/test/test_tools/__init__.py
index eb9acad..61af657 100644
--- a/Lib/test/test_tools/__init__.py
+++ b/Lib/test/test_tools/__init__.py
@@ -4,6 +4,7 @@ import importlib
 import os.path
 import unittest
 from test import support
+from test.support import import_helper
 
 basepath = os.path.normpath(
         os.path.dirname(                 # <src/install dir>
@@ -26,11 +27,11 @@ def skip_if_missing(tool=None):
 @contextlib.contextmanager
 def imports_under_tool(name, *subdirs):
     tooldir = os.path.join(toolsdir, name, *subdirs)
-    with support.DirsOnSysPath(tooldir) as cm:
+    with import_helper.DirsOnSysPath(tooldir) as cm:
         yield cm
 
 def import_tool(toolname):
-    with support.DirsOnSysPath(scriptsdir):
+    with import_helper.DirsOnSysPath(scriptsdir):
         return importlib.import_module(toolname)
 
 def load_tests(*args):