Fixed #36958 -- Reloaded logging config when logging settings are changed in tests.

Thanks JaeHyuck Sa and Jake Howard for the reviews.

2 files changed, 50 insertions, 0 deletions

diff --git a/django/test/signals.py b/django/test/signals.py
index cb78b76114..f594ae434b 100644
--- a/django/test/signals.py
+++ b/django/test/signals.py
@@ -5,6 +5,7 @@ import warnings
 from asgiref.local import Local
 
 from django.apps import apps
+from django.conf import settings
 from django.core.exceptions import ImproperlyConfigured
 from django.core.signals import setting_changed
 from django.db import connections, router
@@ -13,6 +14,7 @@ from django.dispatch import Signal, receiver
 from django.utils import timezone
 from django.utils.formats import FORMAT_SETTINGS, reset_format_cache
 from django.utils.functional import empty
+from django.utils.log import configure_logging
 
 template_rendered = Signal()
 
@@ -251,3 +253,9 @@ def user_model_swapped(*, setting, **kwargs):
             from django.contrib.auth import views
 
             views.UserModel = UserModel
+
+
+@receiver(setting_changed)
+def update_logging_config(*, setting, **kwargs):
+    if setting in {"LOGGING", "LOGGING_CONFIG"}:
+        configure_logging(settings.LOGGING_CONFIG, settings.LOGGING)
diff --git a/tests/logging_tests/tests.py b/tests/logging_tests/tests.py
index a4de7424f8..9690147e81 100644
--- a/tests/logging_tests/tests.py
+++ b/tests/logging_tests/tests.py
@@ -573,6 +573,10 @@ class SetupConfigureLogging(SimpleTestCase):
     Calling django.setup() initializes the logging configuration.
     """
 
+    def tearDown(self):
+        super().tearDown()
+        dictConfig.called = False
+
     def test_configure_initializes_logging(self):
         from django import setup
 
@@ -586,6 +590,44 @@ class SetupConfigureLogging(SimpleTestCase):
             setup()
         self.assertTrue(dictConfig.called)
 
+    def test_logging_settings_changed(self):
+        """
+        Logging is reconfigured when LOGGING or LOGGING_CONFIG changes.
+        """
+        new_logging_info = {
+            "version": 1,
+            "disable_existing_loggers": False,
+            "loggers": {
+                "django.test_custom_logger": {
+                    "level": "INFO",
+                }
+            },
+        }
+        new_logging_warning = {
+            "version": 1,
+            "disable_existing_loggers": False,
+            "loggers": {
+                "django.test_custom_logger": {
+                    "level": "WARNING",
+                }
+            },
+        }
+        logger = logging.getLogger("django.test_custom_logger")
+
+        with override_settings(LOGGING=new_logging_info):
+            self.assertEqual(logger.level, logging.INFO)
+
+        # Repeating the operation works.
+        with override_settings(LOGGING=new_logging_warning):
+            self.assertEqual(logger.level, logging.WARNING)
+
+        # The default unconfigured level is NOTSET.
+        self.assertEqual(logger.level, logging.NOTSET)
+
+        self.assertIs(dictConfig.called, False)
+        with override_settings(LOGGING_CONFIG="logging_tests.tests.dictConfig"):
+            self.assertIs(dictConfig.called, True)
+
 
 @override_settings(DEBUG=True, ROOT_URLCONF="logging_tests.urls")
 class SecurityLoggerTest(LoggingAssertionMixin, SimpleTestCase):