Removed tests for django.utils.unittest vs. unittest.

Silenced warnings caused by the deprecation of django.utils.unittest.

Thanks Preston Timmons and Carl Meyer for their advice.

Fixed #20680.

django/test/simple.py

@@ -12,6 +12,8 @@ from django.db.models import get_app, get_apps
 from django.test import _doctest as doctest
 from django.test import runner
 from django.test.utils import compare_xml, strip_quotes
+# django.utils.unittest is deprecated, but so is django.test.simple,
+# and the latter will be removed before the former.
 from django.utils import unittest
 from django.utils.importlib import import_module
 from django.utils.module_loading import module_has_submodule

django/test/utils.py

@@ -377,13 +377,14 @@ class CaptureQueriesContext(object):
 
 class IgnoreDeprecationWarningsMixin(object):
 
-    warning_class = DeprecationWarning
+    warning_classes = [DeprecationWarning]
 
     def setUp(self):
         super(IgnoreDeprecationWarningsMixin, self).setUp()
         self.catch_warnings = warnings.catch_warnings()
         self.catch_warnings.__enter__()
-        warnings.filterwarnings("ignore", category=self.warning_class)
+        for warning_class in self.warning_classes:
+            warnings.filterwarnings("ignore", category=warning_class)
 
     def tearDown(self):
         self.catch_warnings.__exit__(*sys.exc_info())
@@ -392,7 +393,12 @@ class IgnoreDeprecationWarningsMixin(object):
 
 class IgnorePendingDeprecationWarningsMixin(IgnoreDeprecationWarningsMixin):
 
-        warning_class = PendingDeprecationWarning
+        warning_classes = [PendingDeprecationWarning]
+
+
+class IgnoreAllDeprecationWarningsMixin(IgnoreDeprecationWarningsMixin):
+
+        warning_classes = [PendingDeprecationWarning, DeprecationWarning]
 
 
 @contextmanager