Fixed issue with toolbar expecting urls to start with __debug__.

When the history panel was added and we expanded the number of
urls we were instrumenting, there was a check added to exclude
the requests to the toolbar's views. This was done by checking
the path of the request to see if it started with __debug__.
However, the documentation states that is not a requirement.
This change checks the urls to see if the namespace of the
resolved url matches the toolbar's namespace.

This still isn't perfect as another url path could contain the
last namespace of djdt, but this is much less likely than a user
defining the toolbar's urls at a different path than /__debug__/

debug_toolbar/middleware.py

@@ -44,7 +44,7 @@ def __init__(self, get_response):
     def __call__(self, request):
         # Decide whether the toolbar is active for this request.
         show_toolbar = get_show_toolbar()
-        if not show_toolbar(request) or request.path.startswith("/__debug__/"):
+        if not show_toolbar(request) or DebugToolbar.is_toolbar_request(request):
             return self.get_response(request)
 
         toolbar = DebugToolbar(request, self.get_response)

debug_toolbar/toolbar.py

@@ -9,7 +9,8 @@
 from django.core.exceptions import ImproperlyConfigured
 from django.template import TemplateSyntaxError
 from django.template.loader import render_to_string
-from django.urls import path
+from django.urls import path, resolve
+from django.urls.exceptions import Resolver404
 from django.utils.module_loading import import_string
 
 from debug_toolbar import settings as dt_settings
@@ -133,6 +134,19 @@ def get_urls(cls):
             cls._urlpatterns = urlpatterns
         return cls._urlpatterns
 
+    @classmethod
+    def is_toolbar_request(cls, request):
+        """
+        Determine if the request is for a DebugToolbar view.
+        """
+        # The primary caller of this function is in the middleware which may
+        # not have resolver_match set.
+        try:
+            resolver_match = request.resolver_match or resolve(request.path)
+        except Resolver404:
+            return False
+        return resolver_match.namespaces and resolver_match.namespaces[-1] == app_name
+
 
 app_name = "djdt"
 urlpatterns = DebugToolbar.get_urls()

docs/changes.rst

@@ -9,7 +9,8 @@ Next version
 * Added ``PRETTIFY_SQL`` configuration option to support controlling
   SQL token grouping. By default it's set to True. When set to False,
   a performance improvement can be seen by the SQL panel.
-
+* Fixed issue with toolbar expecting urls to start with `/__debug__/`
+  while the documentation indicates it's not required.
 
 3.2 (2020-12-03)
 ----------------

tests/test_integration.py

@@ -101,6 +101,25 @@ def test_cache_page(self):
         self.client.get("/cached_view/")
         self.assertEqual(len(self.toolbar.get_panel_by_id("CachePanel").calls), 5)
 
+    def test_is_toolbar_request(self):
+        self.request.path = "/__debug__/render_panel/"
+        self.assertTrue(self.toolbar.is_toolbar_request(self.request))
+
+        self.request.path = "/invalid/__debug__/render_panel/"
+        self.assertFalse(self.toolbar.is_toolbar_request(self.request))
+
+        self.request.path = "/render_panel/"
+        self.assertFalse(self.toolbar.is_toolbar_request(self.request))
+
+    @override_settings(ROOT_URLCONF="tests.urls_invalid")
+    def test_is_toolbar_request_without_djdt_urls(self):
+        """Test cases when the toolbar urls aren't configured."""
+        self.request.path = "/__debug__/render_panel/"
+        self.assertFalse(self.toolbar.is_toolbar_request(self.request))
+
+        self.request.path = "/render_panel/"
+        self.assertFalse(self.toolbar.is_toolbar_request(self.request))
+
 
 @override_settings(DEBUG=True)
 class DebugToolbarIntegrationTestCase(IntegrationTestCase):

tests/urls_invalid.py

@@ -0,0 +1,2 @@
+"""Invalid urls.py file for testing"""
+urlpatterns = []