[pull] main from django:main

django/test/testcases.py

@@ -575,6 +575,8 @@ def _assert_contains(self, response, text, status_code, msg_prefix, html):
 
         if response.streaming:
             content = b"".join(response.streaming_content)
+            # Reset the content so it can be checked again (idempotency).
+            response.streaming_content = [content]
         else:
             content = response.content
         response_content = content

docs/releases/6.1.txt

@@ -355,7 +355,11 @@ Templates
 Tests
 ~~~~~
 
-* ...
+* :meth:`~django.test.SimpleTestCase.assertContains` and
+  :meth:`~django.test.SimpleTestCase.assertNotContains` can now be called
+  multiple times on the same :class:`~django.http.StreamingHttpResponse`.
+  Previously, they would consume the streaming response's content, causing
+  subsequent calls to fail.
 
 URLs
 ~~~~

tests/test_utils/tests.py

@@ -29,7 +29,7 @@
     ValidationError,
     formset_factory,
 )
-from django.http import HttpResponse
+from django.http import HttpResponse, StreamingHttpResponse
 from django.template import Context, Template
 from django.template.loader import render_to_string
 from django.test import (
@@ -1047,6 +1047,17 @@ def test_unicode_handling(self):
             html=True,
         )
 
+    def test_streaming_response_idempotent(self):
+        response = StreamingHttpResponse(["hello world"])
+        self.assertContains(response, "hello")
+        self.assertContains(response, "world")
+
+    def test_streaming_response_not_contains_idempotent(self):
+        response = StreamingHttpResponse(["hello world"])
+        self.assertNotContains(response, "bye")
+        self.assertNotContains(response, "bye")
+        self.assertContains(response, "world")
+
 
 class InHTMLTests(SimpleTestCase):
     def test_needle_msg(self):