Added assertMessages() from django.contrib.messages. (#1109)

Author: sdolemelipone

AUTHORS

@@ -19,3 +19,4 @@ Donald Stufft <donald@stufft.io>
 Nicolas Delaby <ticosax@free.fr>
 Hasan Ramezani <hasan.r67@gmail.com>
 Michael Howitz
+Mark Gensler

docs/changelog.rst

@@ -1,6 +1,15 @@
 Changelog
 =========
 
+Pending
+-------
+
+Improvements
+^^^^^^^^^^^^
+
+* Added `pytest.asserts.assertMessages()` to mimic the behaviour of the
+  `django.contrib.messages.test.MessagesTestMixin` function for Django versions >= 5.0.
+
 v4.7.0 (2023-11-08)
 -------------------
 

pytest_django/asserts.py

@@ -6,10 +6,22 @@
 from functools import wraps
 from typing import TYPE_CHECKING, Any, Callable, Sequence
 
+from django import VERSION
 from django.test import LiveServerTestCase, SimpleTestCase, TestCase, TransactionTestCase
 
 
-test_case = TestCase("run")
+USE_CONTRIB_MESSAGES = VERSION >= (5, 0)
+
+if USE_CONTRIB_MESSAGES:
+    from django.contrib.messages import Message
+    from django.contrib.messages.test import MessagesTestMixin
+
+    class MessagesTestCase(MessagesTestMixin, TestCase):
+        pass
+
+    test_case = MessagesTestCase("run")
+else:
+    test_case = TestCase("run")
 
 
 def _wrapper(name: str):
@@ -31,6 +43,11 @@ def assertion_func(*args, **kwargs):
     {attr for attr in vars(TransactionTestCase) if attr.startswith("assert")},
 )
 
+if USE_CONTRIB_MESSAGES:
+    assertions_names.update(
+        {attr for attr in vars(MessagesTestMixin) if attr.startswith("assert")},
+    )
+
 for assert_func in assertions_names:
     globals()[assert_func] = _wrapper(assert_func)
     __all__.append(assert_func)  # noqa: PYI056
@@ -213,6 +230,15 @@ def assertNumQueries(
     ):
         ...
 
+    # Added in Django 5.0.
+    def assertMessages(
+        response: HttpResponseBase,
+        expected_messages: Sequence[Message],
+        *args,
+        ordered: bool = ...,
+    ) -> None:
+        ...
+
     # Fallback in case Django adds new asserts.
     def __getattr__(name: str) -> Callable[..., Any]:
         ...

tests/test_asserts.py

@@ -17,9 +17,18 @@ def _get_actual_assertions_names() -> list[str]:
     """
     from unittest import TestCase as DefaultTestCase
 
+    from django import VERSION
     from django.test import TestCase as DjangoTestCase
 
-    obj = DjangoTestCase("run")
+    if VERSION >= (5, 0):
+        from django.contrib.messages.test import MessagesTestMixin
+
+        class MessagesTestCase(MessagesTestMixin, DjangoTestCase):
+            pass
+
+        obj = MessagesTestCase("run")
+    else:
+        obj = DjangoTestCase("run")
 
     def is_assert(func) -> bool:
         return func.startswith("assert") and "_" not in func