Add test.test_support.guard_warnings_filter . This function returns a context
manager that protects warnings.filter from being modified once the context is
exited.
diff --git a/Doc/lib/libtest.tex b/Doc/lib/libtest.tex
index 54a24b1..d13bfff 100644
--- a/Doc/lib/libtest.tex
+++ b/Doc/lib/libtest.tex
@@ -263,6 +263,10 @@
This does not equal a failure since it could be the path to the file.
\end{funcdesc}
+\begin{funcdesc}{guard_warnings_filter}{}
+Returns a context manager that guards the \module{warnings} module's
+filter settings.
+
\begin{funcdesc}{run_unittest}{*classes}
Execute \class{unittest.TestCase} subclasses passed to the function.
The function scans the classes for methods starting with the prefix
diff --git a/Lib/test/test_import.py b/Lib/test/test_import.py
index 462e266..a6db281 100644
--- a/Lib/test/test_import.py
+++ b/Lib/test/test_import.py
@@ -1,10 +1,11 @@
-from test.test_support import TESTFN, run_unittest
+from test.test_support import TESTFN, run_unittest, guard_warnings_filter
import unittest
import os
import random
import sys
import py_compile
+import warnings
def remove_files(name):
@@ -204,15 +205,11 @@
self.assert_(y is test.test_support, y.__name__)
def test_import_initless_directory_warning(self):
- import warnings
- oldfilters = warnings.filters[:]
- warnings.simplefilter('error', ImportWarning);
- try:
+ with guard_warnings_filter():
# Just a random non-package directory we always expect to be
# somewhere in sys.path...
+ warnings.simplefilter('error', ImportWarning)
self.assertRaises(ImportWarning, __import__, "site-packages")
- finally:
- warnings.filters = oldfilters
def test_main(verbose=None):
run_unittest(ImportTest)
diff --git a/Lib/test/test_random.py b/Lib/test/test_random.py
index bba4c7c..e3f05a0 100644
--- a/Lib/test/test_random.py
+++ b/Lib/test/test_random.py
@@ -178,10 +178,9 @@
def test_bigrand(self):
# Verify warnings are raised when randrange is too large for random()
- oldfilters = warnings.filters[:]
- warnings.filterwarnings("error", "Underlying random")
- self.assertRaises(UserWarning, self.gen.randrange, 2**60)
- warnings.filters[:] = oldfilters
+ with test_support.guard_warnings_filter():
+ warnings.filterwarnings("error", "Underlying random")
+ self.assertRaises(UserWarning, self.gen.randrange, 2**60)
class SystemRandom_TestBasicOps(TestBasicOps):
gen = random.SystemRandom()
diff --git a/Lib/test/test_struct.py b/Lib/test/test_struct.py
index 66fd667..0144a0f 100644
--- a/Lib/test/test_struct.py
+++ b/Lib/test/test_struct.py
@@ -50,22 +50,17 @@
def with_warning_restore(func):
def _with_warning_restore(*args, **kw):
- # The `warnings` module doesn't have an advertised way to restore
- # its filter list. Cheat.
- save_warnings_filters = warnings.filters[:]
- # Grrr, we need this function to warn every time. Without removing
- # the warningregistry, running test_tarfile then test_struct would fail
- # on 64-bit platforms.
- globals = func.func_globals
- if '__warningregistry__' in globals:
- del globals['__warningregistry__']
- warnings.filterwarnings("error", r"""^struct.*""", DeprecationWarning)
- warnings.filterwarnings("error", r""".*format requires.*""",
- DeprecationWarning)
- try:
+ with test.test_support.guard_warnings_filter():
+ # Grrr, we need this function to warn every time. Without removing
+ # the warningregistry, running test_tarfile then test_struct would fail
+ # on 64-bit platforms.
+ globals = func.func_globals
+ if '__warningregistry__' in globals:
+ del globals['__warningregistry__']
+ warnings.filterwarnings("error", r"""^struct.*""", DeprecationWarning)
+ warnings.filterwarnings("error", r""".*format requires.*""",
+ DeprecationWarning)
return func(*args, **kw)
- finally:
- warnings.filters[:] = save_warnings_filters[:]
return _with_warning_restore
def deprecated_err(func, *args):
diff --git a/Lib/test/test_support.py b/Lib/test/test_support.py
index ae39aa1..4939410 100644
--- a/Lib/test/test_support.py
+++ b/Lib/test/test_support.py
@@ -3,7 +3,9 @@
if __name__ != 'test.test_support':
raise ImportError, 'test_support must be imported from the test package'
+from contextlib import contextmanager
import sys
+import warnings
class Error(Exception):
"""Base class for regression test exceptions."""
@@ -268,6 +270,16 @@
print >> get_original_stdout(), '\tfetching %s ...' % url
fn, _ = urllib.urlretrieve(url, filename)
return open(fn)
+
+@contextmanager
+def guard_warnings_filter():
+ """Guard the warnings filter from being permanently changed."""
+ original_filters = warnings.filters[:]
+ try:
+ yield
+ finally:
+ warnings.filters = original_filters
+
#=======================================================================
# Decorator for running a function in a different locale, correctly resetting
diff --git a/Misc/NEWS b/Misc/NEWS
index 667ccaf..4d9c899 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -302,6 +302,10 @@
Tests
-----
+- Added guard_warnings_filter to test.test_support. It returns a context
+ manager that protects the 'warnings' module's filter from being mutated
+ once the context has been exited.
+
- Added some tests for modulefinder.
- Converted test_imp to use unittest.