Add test_lazy_import for pickle, mimetypes, base64, csv, pprint and s…

…ocket modules
python · JelleZijlstra · May 5, 2025 · Apr 27, 2025 · Apr 28, 2025 · May 4, 2025
commit 34e39abfdc1f6e8a825b69c5aac0550fe572d75c
diff --git a/Lib/test/test_base64.py b/Lib/test/test_base64.py
@@ -3,8 +3,16 @@
 import binascii
 import os
 from array import array
+from test.support import cpython_only
 from test.support import os_helper
 from test.support import script_helper
+from test.support.import_helper import ensure_lazy_imports
+
+
+class LazyImportTest(unittest.TestCase):
+    @cpython_only
+    def test_lazy_import(self):
+        ensure_lazy_imports("base64", {"re"})
 
 
 class LegacyBase64TestCase(unittest.TestCase):

diff --git a/Lib/test/test_csv.py b/Lib/test/test_csv.py
@@ -10,7 +10,8 @@
 import gc
 import pickle
 from test import support
-from test.support import import_helper, check_disallow_instantiation
+from test.support import cpython_only, import_helper, check_disallow_instantiation
+from test.support.import_helper import ensure_lazy_imports
 from itertools import permutations
 from textwrap import dedent
 from collections import OrderedDict
@@ -1565,6 +1566,10 @@ class MiscTestCase(unittest.TestCase):
     def test__all__(self):
         support.check__all__(self, csv, ('csv', '_csv'))
 
+    @cpython_only
+    def test_lazy_import(self):
+        ensure_lazy_imports("csv", {"re"})
+
     def test_subclassable(self):
         # issue 44089
         class Foo(csv.Error): ...

@@ -6,7 +6,8 @@
 import unittest.mock
 from platform import win32_edition
 from test import support
-from test.support import os_helper
+from test.support import cpython_only, os_helper
+from test.support.import_helper import ensure_lazy_imports
 from test.support.script_helper import run_python_until_end
 
 try:
@@ -409,6 +410,10 @@ class MiscTestCase(unittest.TestCase):
     def test__all__(self):
         support.check__all__(self, mimetypes)
 
+    @cpython_only
+    def test_lazy_import(self):
+        ensure_lazy_imports("mimetypes", {"os", "posixpath", "urllib.parse"})
+
 
 class CommandLineTest(unittest.TestCase):
     def test_parse_args(self):

@@ -81,7 +81,7 @@ def test_is_notimplemented(self):
         self.assertTrue(isinstance(pathlib.UnsupportedOperation(), NotImplementedError))
 
 
-class TestImportTime(unittest.TestCase):
+class LazyImportTest(unittest.TestCase):
     @cpython_only
     def test_lazy_import(self):
         import_helper.ensure_lazy_imports("pathlib", {"shutil"})

diff --git a/Lib/test/test_pickle.py b/Lib/test/test_pickle.py
@@ -15,7 +15,8 @@
 import doctest
 import unittest
 from test import support
-from test.support import import_helper, os_helper
+from test.support import cpython_only, import_helper, os_helper
+from test.support.import_helper import ensure_lazy_imports
 
 from test.pickletester import AbstractHookTests
 from test.pickletester import AbstractUnpickleTests
@@ -36,6 +37,12 @@
     has_c_implementation = False
 
 
+class LazyImportTest(unittest.TestCase):
+    @cpython_only
+    def test_lazy_import(self):
+        ensure_lazy_imports("pickle", {"re"})
+
+
 class PyPickleTests(AbstractPickleModuleTests, unittest.TestCase):
     dump = staticmethod(pickle._dump)
     dumps = staticmethod(pickle._dumps)

diff --git a/Lib/test/test_pprint.py b/Lib/test/test_pprint.py
@@ -11,6 +11,9 @@
 import types
 import unittest
 
+from test.support import cpython_only
+from test.support.import_helper import ensure_lazy_imports
+
 # list, tuple and dict subclasses that do or don't overwrite __repr__
 class list2(list):
     pass
@@ -129,6 +132,10 @@ def setUp(self):
         self.b = list(range(200))
         self.a[-12] = self.b
 
+    @cpython_only
+    def test_lazy_import(self):
+        ensure_lazy_imports("pprint", {"dataclasses", "re"})
+
     def test_init(self):
         pp = pprint.PrettyPrinter()
         pp = pprint.PrettyPrinter(indent=4, width=40, depth=5,

diff --git a/Lib/test/test_socket.py b/Lib/test/test_socket.py
@@ -2,8 +2,9 @@
 from unittest import mock
 from test import support
 from test.support import (
-    is_apple, os_helper, refleak_helper, socket_helper, threading_helper
+    cpython_only, is_apple, os_helper, refleak_helper, socket_helper, threading_helper
 )
+from test.support.import_helper import ensure_lazy_imports
 import _thread as thread
 import array
 import contextlib
@@ -257,6 +258,12 @@ def downgrade_malformed_data_warning():
 # Size in bytes of the int type
 SIZEOF_INT = array.array("i").itemsize
 
+class TestLazyImport(unittest.TestCase):
+    @cpython_only
+    def test_lazy_import(self):
+        ensure_lazy_imports("socket", {"array", "selectors"})
+
+
 class SocketTCPTest(unittest.TestCase):
 
     def setUp(self):