[5.1.x] Refs #26688 -- Added tests for log_response() internal helper.

Backport of 897046815944cc9a2da7ed9e8082f45ffe8110e3 from main.

tests/logging_tests/tests.py

@@ -1,7 +1,7 @@
 import logging
 from contextlib import contextmanager
 from io import StringIO
-from unittest import mock
+from unittest import TestCase, mock
 
 from admin_scripts.tests import AdminScriptTestCase
 
@@ -10,6 +10,7 @@ from django.core import mail
 from django.core.exceptions import DisallowedHost, PermissionDenied, SuspiciousOperation
 from django.core.files.temp import NamedTemporaryFile
 from django.core.management import color
+from django.http import HttpResponse
 from django.http.multipartparser import MultiPartParserError
 from django.test import RequestFactory, SimpleTestCase, override_settings
 from django.test.utils import LoggingCaptureMixin
@@ -20,6 +21,7 @@ from django.utils.log import (
     RequireDebugFalse,
     RequireDebugTrue,
     ServerFormatter,
+    log_response,
 )
 from django.views.debug import ExceptionReporter
 
@@ -665,3 +667,122 @@ class LogFormattersTests(SimpleTestCase):
             self.assertRegex(
                 logger_output.getvalue(), r"^\[[/:,\w\s\d]+\] %s\n" % log_msg
             )
+
+
+class LogResponseRealLoggerTests(TestCase):
+
+    request = RequestFactory().get("/test-path/")
+
+    def assertResponseLogged(self, logger_cm, msg, levelno, status_code, request):
+        self.assertEqual(
+            records_len := len(logger_cm.records),
+            1,
+            f"Unexpected number of records for {logger_cm=} in {levelno=} (expected 1, "
+            f"got {records_len}).",
+        )
+        record = logger_cm.records[0]
+        self.assertEqual(record.getMessage(), msg)
+        self.assertEqual(record.levelno, levelno)
+        self.assertEqual(record.status_code, status_code)
+        self.assertEqual(record.request, request)
+
+    def test_missing_response_raises_attribute_error(self):
+        with self.assertRaises(AttributeError):
+            log_response("No response provided", response=None, request=self.request)
+
+    def test_missing_request_logs_with_none(self):
+        response = HttpResponse(status=403)
+        with self.assertLogs("django.request", level="INFO") as cm:
+            log_response(msg := "Missing request", response=response, request=None)
+        self.assertResponseLogged(cm, msg, logging.WARNING, 403, request=None)
+
+    def test_logs_5xx_as_error(self):
+        response = HttpResponse(status=508)
+        with self.assertLogs("django.request", level="ERROR") as cm:
+            log_response(
+                msg := "Server error occurred", response=response, request=self.request
+            )
+        self.assertResponseLogged(cm, msg, logging.ERROR, 508, self.request)
+
+    def test_logs_4xx_as_warning(self):
+        response = HttpResponse(status=418)
+        with self.assertLogs("django.request", level="WARNING") as cm:
+            log_response(
+                msg := "This is a teapot!", response=response, request=self.request
+            )
+        self.assertResponseLogged(cm, msg, logging.WARNING, 418, self.request)
+
+    def test_logs_2xx_as_info(self):
+        response = HttpResponse(status=201)
+        with self.assertLogs("django.request", level="INFO") as cm:
+            log_response(msg := "OK response", response=response, request=self.request)
+        self.assertResponseLogged(cm, msg, logging.INFO, 201, self.request)
+
+    def test_custom_log_level(self):
+        response = HttpResponse(status=403)
+        with self.assertLogs("django.request", level="DEBUG") as cm:
+            log_response(
+                msg := "Debug level log",
+                response=response,
+                request=self.request,
+                level="debug",
+            )
+        self.assertResponseLogged(cm, msg, logging.DEBUG, 403, self.request)
+
+    def test_logs_only_once_per_response(self):
+        response = HttpResponse(status=500)
+        with self.assertLogs("django.request", level="ERROR") as cm:
+            log_response("First log", response=response, request=self.request)
+            log_response("Second log", response=response, request=self.request)
+        self.assertResponseLogged(cm, "First log", logging.ERROR, 500, self.request)
+
+    def test_exc_info_output(self):
+        response = HttpResponse(status=500)
+        try:
+            raise ValueError("Simulated failure")
+        except ValueError as exc:
+            with self.assertLogs("django.request", level="ERROR") as cm:
+                log_response(
+                    "With exception",
+                    response=response,
+                    request=self.request,
+                    exception=exc,
+                )
+        self.assertResponseLogged(
+            cm, "With exception", logging.ERROR, 500, self.request
+        )
+        self.assertIn("ValueError", "\n".join(cm.output))  # Stack trace included
+
+    def test_format_args_are_applied(self):
+        response = HttpResponse(status=500)
+        with self.assertLogs("django.request", level="ERROR") as cm:
+            log_response(
+                "Something went wrong: %s (%d)",
+                "DB error",
+                42,
+                response=response,
+                request=self.request,
+            )
+        msg = "Something went wrong: DB error (42)"
+        self.assertResponseLogged(cm, msg, logging.ERROR, 500, self.request)
+
+    def test_logs_with_custom_logger(self):
+        handler = logging.StreamHandler(log_stream := StringIO())
+        handler.setFormatter(logging.Formatter("%(levelname)s:%(name)s:%(message)s"))
+
+        custom_logger = logging.getLogger("my.custom.logger")
+        custom_logger.setLevel(logging.DEBUG)
+        custom_logger.addHandler(handler)
+        self.addCleanup(custom_logger.removeHandler, handler)
+
+        response = HttpResponse(status=404)
+        log_response(
+            msg := "Handled by custom logger",
+            response=response,
+            request=self.request,
+            logger=custom_logger,
+        )
+
+        self.assertEqual(
+            f"WARNING:my.custom.logger:{msg}", log_stream.getvalue().strip()
+        )