Fixed #14508 - test suite silences warnings.

Utility functions get_warnings_state and save_warnings_state have been added
to django.test.utils, and methods to django.test.TestCase for convenience.

The implementation is based on the catch_warnings context manager from
Python 2.6.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@14526 bcc190cf-cafb-0310-a4f2-bffc1f526a37

2 files changed, 36 insertions, 0 deletions

diff --git a/django/test/testcases.py b/django/test/testcases.py
index 57472f7631..398ad774d8 100644
--- a/django/test/testcases.py
+++ b/django/test/testcases.py
@@ -11,6 +11,7 @@ from django.db import transaction, connection, connections, DEFAULT_DB_ALIAS
 from django.http import QueryDict
 from django.test import _doctest as doctest
 from django.test.client import Client
+from django.test.utils import get_warnings_state, restore_warnings_state
 from django.utils import simplejson, unittest as ut2
 from django.utils.encoding import smart_str
 from django.utils.functional import wraps
@@ -328,6 +329,19 @@ class TransactionTestCase(ut2.TestCase):
             settings.ROOT_URLCONF = self._old_root_urlconf
             clear_url_caches()
 
+    def save_warnings_state(self):
+        """
+        Saves the state of the warnings module
+        """
+        self._warnings_state = get_warnings_state()
+
+    def restore_warnings_state(self):
+        """
+        Restores the sate of the warnings module to the state
+        saved by save_warnings_state()
+        """
+        restore_warnings_state(self._warnings_state)
+
     def assertRedirects(self, response, expected_url, status_code=302,
                         target_status_code=200, host=None, msg_prefix=''):
         """Asserts that a response redirected to a specific URL, and that the
diff --git a/django/test/utils.py b/django/test/utils.py
index 063e30297f..90a8b3e88f 100644
--- a/django/test/utils.py
+++ b/django/test/utils.py
@@ -1,6 +1,7 @@
 import sys
 import time
 import os
+import warnings
 from django.conf import settings
 from django.core import mail
 from django.core.mail.backends import locmem
@@ -46,6 +47,7 @@ class ContextList(list):
             return False
         return True
 
+
 def instrumented_test_render(self, context):
     """
     An instrumented Template render method, providing a signal
@@ -75,6 +77,7 @@ def setup_test_environment():
 
     deactivate()
 
+
 def teardown_test_environment():
     """Perform any global post-test teardown. This involves:
 
@@ -93,6 +96,25 @@ def teardown_test_environment():
 
     del mail.outbox
 
+
+def get_warnings_state():
+    """
+    Returns an object containing the state of the warnings module
+    """
+    # There is no public interface for doing this, but this implementation of
+    # get_warnings_state and restore_warnings_state appears to work on Python
+    # 2.4 to 2.7.
+    return warnings.filters[:]
+
+
+def restore_warnings_state(state):
+    """
+    Restores the state of the warnings module when passed an object that was
+    returned by get_warnings_state()
+    """
+    warnings.filters = state[:]
+
+
 def get_runner(settings):
     test_path = settings.TEST_RUNNER.split('.')
     # Allow for Python 2.5 relative paths