[1.2.X] 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.

Backport of [14526] from trunk.

git-svn-id: http://code.djangoproject.com/svn/django/branches/releases/1.2.X@14527 bcc190cf-cafb-0310-a4f2-bffc1f526a37

2 files changed, 12 insertions, 13 deletions

diff --git a/tests/regressiontests/cache/tests.py b/tests/regressiontests/cache/tests.py
index 1e0a4046bb..7167e2fbf8 100644
--- a/tests/regressiontests/cache/tests.py
+++ b/tests/regressiontests/cache/tests.py
@@ -16,6 +16,7 @@ from django.core.cache import get_cache
 from django.core.cache.backends.base import InvalidCacheBackendError, CacheKeyWarning
 from django.http import HttpResponse, HttpRequest
 from django.middleware.cache import FetchFromCacheMiddleware, UpdateCacheMiddleware
+from django.test.utils import get_warnings_state, restore_warnings_state
 from django.utils import translation
 from django.utils.cache import patch_vary_headers, get_cache_key, learn_cache_key
 from django.utils.hashcompat import md5_constructor
@@ -379,20 +380,16 @@ class BaseCacheTests(object):
         # manager to test this warning nicely. Since we can't do that
         # yet, the cleanest option is to temporarily ask for
         # CacheKeyWarning to be raised as an exception.
+        _warnings_state = get_warnings_state()
         warnings.simplefilter("error", CacheKeyWarning)
 
-        # memcached does not allow whitespace or control characters in keys
-        self.assertRaises(CacheKeyWarning, self.cache.set, 'key with spaces', 'value')
-        # memcached limits key length to 250
-        self.assertRaises(CacheKeyWarning, self.cache.set, 'a' * 251, 'value')
-
-        # The warnings module has no public API for getting the
-        # current list of warning filters, so we can't save that off
-        # and reset to the previous value, we have to globally reset
-        # it. The effect will be the same, as long as the Django test
-        # runner doesn't add any global warning filters (it currently
-        # does not).
-        warnings.resetwarnings()
+        try:
+            # memcached does not allow whitespace or control characters in keys
+            self.assertRaises(CacheKeyWarning, self.cache.set, 'key with spaces', 'value')
+            # memcached limits key length to 250
+            self.assertRaises(CacheKeyWarning, self.cache.set, 'a' * 251, 'value')
+        finally:
+            restore_warnings_state(_warnings_state)
 
 class DBCacheTests(unittest.TestCase, BaseCacheTests):
     def setUp(self):
diff --git a/tests/regressiontests/templates/loaders.py b/tests/regressiontests/templates/loaders.py
index caa3faa6bc..47cd18ae21 100644
--- a/tests/regressiontests/templates/loaders.py
+++ b/tests/regressiontests/templates/loaders.py
@@ -21,6 +21,7 @@ from django.template import TemplateDoesNotExist, Context
 from django.template.loaders.eggs import load_template_source as lts_egg
 from django.template.loaders.eggs import Loader as EggLoader
 from django.template import loader
+from django.test.utils import get_warnings_state, restore_warnings_state
 
 # Mock classes and objects for pkg_resources functions.
 class MockProvider(pkg_resources.NullProvider):
@@ -67,11 +68,12 @@ class DeprecatedEggLoaderTest(unittest.TestCase):
         })
         self._old_installed_apps = settings.INSTALLED_APPS
         settings.INSTALLED_APPS = []
+        self._warnings_state = get_warnings_state()
         warnings.simplefilter("ignore", PendingDeprecationWarning)
 
     def tearDown(self):
         settings.INSTALLED_APPS = self._old_installed_apps
-        warnings.resetwarnings()
+        restore_warnings_state(self._warnings_state)
 
     def test_existing(self):
         "A template can be loaded from an egg"