Issue 7994: Make object.__format__ with a non-empty format string a PendingDecprecationWarning. Still need to remove uses of this from various tests.
diff --git a/Lib/test/test_builtin.py b/Lib/test/test_builtin.py
index 05686b9..013731c 100644
--- a/Lib/test/test_builtin.py
+++ b/Lib/test/test_builtin.py
@@ -4,6 +4,7 @@
import unittest
from test.test_support import fcmp, have_unicode, TESTFN, unlink, \
run_unittest, check_py3k_warnings
+import warnings
from operator import neg
import sys, cStringIO, random, UserDict
@@ -1483,6 +1484,41 @@
self.assertRaises(TypeError, object().__format__, object())
self.assertRaises(TypeError, object().__format__, None)
+ # --------------------------------------------------------------------
+ # Issue #7994: object.__format__ with a non-empty format string is
+ # pending deprecated
+ def test_deprecated_format_string(obj, fmt_str, should_raise_warning):
+ with warnings.catch_warnings(record=True) as w:
+ warnings.simplefilter("always", PendingDeprecationWarning)
+ format(obj, fmt_str)
+ if should_raise_warning:
+ self.assertEqual(len(w), 1)
+ self.assertIsInstance(w[0].message, PendingDeprecationWarning)
+ self.assertIn('object.__format__ with a non-empty format '
+ 'string', str(w[0].message))
+ else:
+ self.assertEqual(len(w), 0)
+
+ fmt_strs = ['', 's', u'', u's']
+
+ class A:
+ def __format__(self, fmt_str):
+ return format('', fmt_str)
+
+ for fmt_str in fmt_strs:
+ test_deprecated_format_string(A(), fmt_str, False)
+
+ class B:
+ pass
+
+ class C(object):
+ pass
+
+ for cls in [object, B, C]:
+ for fmt_str in fmt_strs:
+ test_deprecated_format_string(cls(), fmt_str, len(fmt_str) != 0)
+ # --------------------------------------------------------------------
+
# make sure we can take a subclass of str as a format spec
class DerivedFromStr(str): pass
self.assertEqual(format(0, DerivedFromStr('10')), ' 0')