From 2e153215d1a18953dfd37edb06b5764ca0077bd3 Mon Sep 17 00:00:00 2001
From: Johannes Maron <johannes@maron.family>
Date: Sun, 11 Feb 2024 11:32:16 +0100
Subject: [PATCH] Ref #558 -- QED

---
 tests/test_django_whitenoise.py | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/tests/test_django_whitenoise.py b/tests/test_django_whitenoise.py
index 48c25496..4f855302 100644
--- a/tests/test_django_whitenoise.py
+++ b/tests/test_django_whitenoise.py
@@ -3,6 +3,7 @@
 import shutil
 import tempfile
 from contextlib import closing
+from unittest.mock import Mock
 from urllib.parse import urljoin
 from urllib.parse import urlparse
 
@@ -12,6 +13,7 @@
 from django.contrib.staticfiles import storage
 from django.core.management import call_command
 from django.core.wsgi import get_wsgi_application
+from django.test import Client
 from django.test.utils import override_settings
 from django.utils.functional import empty
 
@@ -209,3 +211,17 @@ def test_relative_static_url(server, static_files, _collect_static):
         url = storage.staticfiles_storage.url(static_files.js_path)
         response = server.get(url)
         assert response.content == static_files.js_content
+
+
+def test_middleware__performance(monkeypatch):
+    """The middleware should not on every request."""
+    scantree = Mock()
+    scantree.return_value = []
+    monkeypatch.setattr("whitenoise.base.scantree", scantree)
+    with override_settings(
+        MIDDLEWARE=["whitenoise.middleware.WhiteNoiseMiddleware", *settings.MIDDLEWARE]
+    ):
+        # every Django test will set up its own client and initialize a new middleware
+        Client().get("/")
+        Client().get("/")
+        assert scantree.assert_called_once()