Refs #15727 -- Updated AdminSeleniumTestCase to use ContentSecurityPolicyMiddleware.

Replaced the custom CSP middleware previously used in the admin's
AdminSeleniumTestCase with the official ContentSecurityPolicyMiddleware.
This change ensures alignment with Django's built-in CSP support.

Also updates the test logic to inspect browser console logs to assert
that no CSP violations are triggered during Selenium admin tests.

django/contrib/admin/tests.py

@@ -1,24 +1,27 @@
 from contextlib import contextmanager
 
 from django.contrib.staticfiles.testing import StaticLiveServerTestCase
-from django.test import modify_settings
+from django.test import modify_settings, override_settings
 from django.test.selenium import SeleniumTestCase
-from django.utils.deprecation import MiddlewareMixin
+from django.utils.csp import CSP
 from django.utils.translation import gettext as _
 
 # Make unittest ignore frames in this module when reporting failures.
 __unittest = True
 
 
-class CSPMiddleware(MiddlewareMixin):
+@modify_settings(
-    """The admin's JavaScript should be compatible with CSP."""
+    MIDDLEWARE={"append": "django.middleware.csp.ContentSecurityPolicyMiddleware"}
-
+)
-    def process_response(self, request, response):
+@override_settings(
-        response.headers["Content-Security-Policy"] = "default-src 'self'"
+    SECURE_CSP={
-        return response
+        "default-src": [CSP.NONE],
-
+        "connect-src": [CSP.SELF],
-
+        "img-src": [CSP.SELF],
-@modify_settings(MIDDLEWARE={"append": "django.contrib.admin.tests.CSPMiddleware"})
+        "script-src": [CSP.SELF],
+        "style-src": [CSP.SELF],
+    },
+)
 class AdminSeleniumTestCase(SeleniumTestCase, StaticLiveServerTestCase):
     available_apps = [
         "django.contrib.admin",
@@ -28,6 +31,11 @@ class AdminSeleniumTestCase(SeleniumTestCase, StaticLiveServerTestCase):
         "django.contrib.sites",
     ]
 
+    def tearDown(self):
+        # Ensure that no CSP violations were logged in the browser.
+        self.assertEqual(self.get_browser_logs(source="security"), [])
+        super().tearDown()
+
     def wait_until(self, callback, timeout=10):
         """
         Block the execution of the tests until the specified callback returns a

django/test/selenium.py

@@ -77,7 +77,11 @@ class SeleniumTestCaseBase(type(LiveServerTestCase)):
     def get_capability(cls, browser):
         from selenium.webdriver.common.desired_capabilities import DesiredCapabilities
 
-        return getattr(DesiredCapabilities, browser.upper())
+        caps = getattr(DesiredCapabilities, browser.upper())
+        if browser == "chrome":
+            caps["goog:loggingPrefs"] = {"browser": "ALL"}
+
+        return caps
 
     def create_options(self):
         options = self.import_options(self.browser)()
@@ -237,6 +241,19 @@ class SeleniumTestCase(LiveServerTestCase, metaclass=SeleniumTestCaseBase):
         path.parent.mkdir(exist_ok=True, parents=True)
         self.selenium.save_screenshot(path)
 
+    def get_browser_logs(self, source=None, level="ALL"):
+        """Return Chrome console logs filtered by level and optionally source."""
+        try:
+            logs = self.selenium.get_log("browser")
+        except AttributeError:
+            logs = []
+        return [
+            log
+            for log in logs
+            if (level == "ALL" or log["level"] == level)
+            and (source is None or log["source"] == source)
+        ]
+
     @classmethod
     def _quit_selenium(cls):
         # quit() the WebDriver before attempting to terminate and join the