Adjusted URLPatternsTestCase to use addClassCleanup() from Django 4.0.

Refs faba5b702a.

addClassCleanup() is available from Python 3.8, which is the minimum supported
Python from Django 4.0.

rest_framework/test.py

@@ -3,6 +3,7 @@
 import io
 from importlib import import_module
 
+import django
 from django.conf import settings
 from django.core.exceptions import ImproperlyConfigured
 from django.core.handlers.wsgi import WSGIHandler
@@ -357,6 +358,13 @@ class APILiveServerTestCase(testcases.LiveServerTestCase):
     client_class = APIClient
 
 
+def cleanup_url_patterns(cls):
+    if hasattr(cls, '_module_urlpatterns'):
+        cls._module.urlpatterns = cls._module_urlpatterns
+    else:
+        del cls._module.urlpatterns
+
+
 class URLPatternsTestCase(testcases.SimpleTestCase):
     """
     Isolate URL patterns on a per-TestCase basis. For example,
@@ -385,8 +393,14 @@ class URLPatternsTestCase(testcases.SimpleTestCase):
         cls._module.urlpatterns = cls.urlpatterns
 
         cls._override.enable()
+
+        if django.VERSION > (4, 0):
+            cls.addClassCleanup(cls._override.disable)
+            cls.addClassCleanup(cleanup_url_patterns, cls)
+
         super().setUpClass()
 
+    if django.VERSION < (4, 0):
         @classmethod
         def tearDownClass(cls):
             super().tearDownClass()

tests/test_testing.py

@@ -1,5 +1,6 @@
 from io import BytesIO
 
+import django
 from django.contrib.auth.models import User
 from django.shortcuts import redirect
 from django.test import TestCase, override_settings
@@ -282,6 +283,10 @@ class TestAPIRequestFactory(TestCase):
         assert request.META['CONTENT_TYPE'] == 'application/json'
 
 
+def check_urlpatterns(cls):
+    assert urlpatterns is not cls.urlpatterns
+
+
 class TestUrlPatternTestCase(URLPatternsTestCase):
     urlpatterns = [
         path('', view),
@@ -293,6 +298,13 @@ class TestUrlPatternTestCase(URLPatternsTestCase):
         super().setUpClass()
         assert urlpatterns is cls.urlpatterns
 
+        if django.VERSION > (4, 0):
+            cls.addClassCleanup(
+                check_urlpatterns,
+                cls
+            )
+
+    if django.VERSION < (4, 0):
         @classmethod
         def tearDownClass(cls):
             assert urlpatterns is cls.urlpatterns