Async compatible HistoryPanel (#1991)

* async compatible history panel

* Update debug_toolbar/toolbar.py

Author: salty-ivy

debug_toolbar/panels/history/panel.py

@@ -16,6 +16,7 @@
 class HistoryPanel(Panel):
     """A panel to display History"""
 
+    is_async = True
     title = _("History")
     nav_title = _("History")
     template = "debug_toolbar/panels/history.html"

debug_toolbar/toolbar.py

@@ -12,6 +12,7 @@
 from django.apps import apps
 from django.conf import settings
 from django.core.exceptions import ImproperlyConfigured
+from django.core.handlers.asgi import ASGIRequest
 from django.dispatch import Signal
 from django.template import TemplateSyntaxError
 from django.template.loader import render_to_string
@@ -101,12 +102,18 @@ def should_render_panels(self):
         If False, the panels will be loaded via Ajax.
         """
         if (render_panels := self.config["RENDER_PANELS"]) is None:
-            # If wsgi.multiprocess isn't in the headers, then it's likely
-            # being served by ASGI. This type of set up is most likely
-            # incompatible with the toolbar until
-            # https://github.com/jazzband/django-debug-toolbar/issues/1430
-            # is resolved.
-            render_panels = self.request.META.get("wsgi.multiprocess", True)
+            # If wsgi.multiprocess is true then it is either being served
+            # from ASGI or multithreaded third-party WSGI server eg gunicorn.
+            # we need to make special check for ASGI for supporting
+            # async context based requests.
+            if isinstance(self.request, ASGIRequest):
+                render_panels = False
+            else:
+                # The wsgi.multiprocess case of being True isn't supported until the
+                # toolbar has resolved the following issue:
+                # This type of set up is most likely
+                # https://github.com/jazzband/django-debug-toolbar/issues/1430
+                render_panels = self.request.META.get("wsgi.multiprocess", True)
         return render_panels
 
     # Handle storing toolbars in memory and fetching them later on

docs/architecture.rst

@@ -82,7 +82,7 @@ Problematic Parts
 - Support for async and multi-threading: ``debug_toolbar.middleware.DebugToolbarMiddleware``
   is now async compatible and can process async requests. However certain
   panels such as ``SQLPanel``, ``TimerPanel``,
-  ``RequestPanel``, ``HistoryPanel`` and ``ProfilingPanel`` aren't fully
+  ``RequestPanel`` and ``ProfilingPanel`` aren't fully
   compatible and currently being worked on. For now, these panels
   are disabled by default when running in async environment.
   follow the progress of this issue in `Async compatible toolbar project <https://github.com/orgs/jazzband/projects/9>`_.

tests/test_integration.py

@@ -11,7 +11,7 @@
 from django.db import connection
 from django.http import HttpResponse
 from django.template.loader import get_template
-from django.test import RequestFactory
+from django.test import AsyncRequestFactory, RequestFactory
 from django.test.utils import override_settings
 
 from debug_toolbar.forms import SignedDataForm
@@ -126,6 +126,22 @@ def test_should_render_panels_multiprocess(self):
         request.META.pop("wsgi.multiprocess")
         self.assertTrue(toolbar.should_render_panels())
 
+    def test_should_render_panels_asgi(self):
+        """
+        The toolbar not should render the panels on each request when wsgi.multiprocess
+        is True or missing in case of async context rather than multithreaded
+        wsgi.
+        """
+        async_request = AsyncRequestFactory().get("/")
+        # by default ASGIRequest will have wsgi.multiprocess set to True
+        # but we are still assigning this to true cause this could change
+        # and we specifically need to check that method returns false even with
+        # wsgi.multiprocess set to true
+        async_request.META["wsgi.multiprocess"] = True
+        toolbar = DebugToolbar(async_request, self.get_response)
+        toolbar.config["RENDER_PANELS"] = None
+        self.assertFalse(toolbar.should_render_panels())
+
     def _resolve_stats(self, path):
         # takes stats from Request panel
         request = rf.get(path)