Deduplicate staticfiles (#2155)

Currently, the staticfiles panel contains one entry per static() call. That's not the same thing as used staticfiles, since assets can be deduplicated in multiple ways, e.g. through forms.Media or because the browser actually understands that it should load <script type="module"> once only.

I think it makes more sense to show a deduplicated and sorted list of static files used.

Refs matthiask/django-prose-editor#48

Author: matthiask

debug_toolbar/panels/staticfiles.py

@@ -1,6 +1,7 @@
 import contextlib
 import uuid
 from contextvars import ContextVar
+from dataclasses import dataclass
 from os.path import join, normpath
 
 from django.contrib.staticfiles import finders, storage
@@ -10,14 +11,14 @@
 from debug_toolbar import panels
 
 
+@dataclass(eq=True, frozen=True)
 class StaticFile:
     """
     Representing the different properties of a static file.
     """
 
-    def __init__(self, *, path, url):
-        self.path = path
-        self._url = url
+    path: str
+    url: str
 
     def __str__(self):
         return self.path
@@ -72,7 +73,7 @@ def title(self):
     def __init__(self, *args, **kwargs):
         super().__init__(*args, **kwargs)
         self.num_found = 0
-        self.used_paths = []
+        self.used_paths = set()
         self.request_id = str(uuid.uuid4())
 
     @classmethod
@@ -88,7 +89,7 @@ def _store_static_files_signal_handler(self, sender, staticfile, **kwargs):
         # concurrent connections and we want to avoid storing of same
         # staticfile from other connections as well.
         if request_id_context_var.get() == self.request_id:
-            self.used_paths.append(staticfile)
+            self.used_paths.add(staticfile)
 
     def enable_instrumentation(self):
         self.ctx_token = request_id_context_var.set(self.request_id)
@@ -112,7 +113,7 @@ def generate_stats(self, request, response):
             {
                 "num_found": self.num_found,
                 "num_used": len(self.used_paths),
-                "staticfiles": self.used_paths,
+                "staticfiles": sorted(self.used_paths),
                 "staticfiles_apps": self.get_staticfiles_apps(),
                 "staticfiles_dirs": self.get_staticfiles_dirs(),
                 "staticfiles_finders": self.get_staticfiles_finders(),

docs/changes.rst

@@ -30,6 +30,7 @@ Pending
 * Extend example app to contain an async version.
 * Added ``debug_toolbar.store.DatabaseStore`` for persistent debug data
   storage.
+* Deduplicated static files in the staticfiles panel.
 
 5.2.0 (2025-04-29)
 ------------------

docs/spelling_wordlist.txt

@@ -17,6 +17,7 @@ biome
 checkbox
 contrib
 csp
+deduplicated
 dicts
 django
 fallbacks

tests/templates/staticfiles/path.html

@@ -1 +1,3 @@
-{% load static %}{% static path %}
+{% load static %}
+{# A single file used twice #}
+{% static path %}{% static path %}