Move settings reset logic to settings module. (#1559)

This makes it apply in every project using django-debug-toolbar, so packages or projects can reconfigure the toolbar during tests if required.

The receiver functions have also been combined and optimized the signature like django/django#15185 .

Author: adamchainz

debug_toolbar/settings.py

@@ -1,6 +1,8 @@
 from functools import lru_cache
 
 from django.conf import settings
+from django.dispatch import receiver
+from django.test.signals import setting_changed
 
 CONFIG_DEFAULTS = {
     # Toolbar options
@@ -71,3 +73,18 @@ def get_panels():
     except AttributeError:
         PANELS = PANELS_DEFAULTS
     return PANELS
+
+
+@receiver(setting_changed)
+def update_toolbar_config(*, setting, **kwargs):
+    """
+    Refresh configuration when overriding settings.
+    """
+    if setting == "DEBUG_TOOLBAR_CONFIG":
+        get_config.cache_clear()
+    elif setting == "DEBUG_TOOLBAR_PANELS":
+        from debug_toolbar.toolbar import DebugToolbar
+
+        get_panels.cache_clear()
+        DebugToolbar._panel_classes = None
+        # Not implemented: invalidate debug_toolbar.urls.

docs/changes.rst

@@ -7,6 +7,9 @@ Next version
 * Removed support for Django < 3.2.
 * Updated check ``W006`` to look for
   ``django.template.loaders.app_directories.Loader``.
+* Reset settings when overridden in tests. Packages or projects using
+  django-debug-toolbar can now use Django’s test settings tools, like
+  ``@override_settings``, to reconfigure the toolbar during tests.
 
 3.2.4 (2021-12-15)
 ------------------

tests/__init__.py

@@ -1,21 +0,0 @@
-# Refresh the debug toolbar's configuration when overriding settings.
-
-from django.dispatch import receiver
-from django.test.signals import setting_changed
-
-from debug_toolbar import settings as dt_settings
-from debug_toolbar.toolbar import DebugToolbar
-
-
-@receiver(setting_changed)
-def update_toolbar_config(**kwargs):
-    if kwargs["setting"] == "DEBUG_TOOLBAR_CONFIG":
-        dt_settings.get_config.cache_clear()
-
-
-@receiver(setting_changed)
-def update_toolbar_panels(**kwargs):
-    if kwargs["setting"] == "DEBUG_TOOLBAR_PANELS":
-        dt_settings.get_panels.cache_clear()
-        DebugToolbar._panel_classes = None
-        # Not implemented: invalidate debug_toolbar.urls.