bpo-34556: Add --upgrade-deps to venv module (#13100)

Add --upgrade-deps to venv module
- This allows for pip + setuptools to be automatically upgraded to the latest version on PyPI
- Update documentation to represent this change

bpo-34556: Add --upgrade to venv module

1 files changed, 23 insertions, 1 deletions

diff --git a/Lib/test/test_venv.py b/Lib/test/test_venv.py
index 24d3a69..4f6c11b 100644
--- a/Lib/test/test_venv.py
+++ b/Lib/test/test_venv.py
@@ -16,9 +16,9 @@ import tempfile
 from test.support import (captured_stdout, captured_stderr, requires_zlib,
                           can_symlink, EnvironmentVarGuard, rmtree,
                           import_module)
-import threading
 import unittest
 import venv
+from unittest.mock import patch
 
 try:
     import ctypes
@@ -131,6 +131,28 @@ class BasicTest(BaseTest):
         self.assertEqual(context.prompt, '(My prompt) ')
         self.assertIn("prompt = 'My prompt'\n", data)
 
+    def test_upgrade_dependencies(self):
+        builder = venv.EnvBuilder()
+        bin_path = 'Scripts' if sys.platform == 'win32' else 'bin'
+        pip_exe = 'pip.exe' if sys.platform == 'win32' else 'pip'
+        with tempfile.TemporaryDirectory() as fake_env_dir:
+
+            def pip_cmd_checker(cmd):
+                self.assertEqual(
+                    cmd,
+                    [
+                        os.path.join(fake_env_dir, bin_path, pip_exe),
+                        'install',
+                        '-U',
+                        'pip',
+                        'setuptools'
+                    ]
+                )
+
+            fake_context = builder.ensure_directories(fake_env_dir)
+            with patch('venv.subprocess.check_call', pip_cmd_checker):
+                builder.upgrade_dependencies(fake_context)
+
     @requireVenvCreate
     def test_prefixes(self):
         """