diff --git a/django/utils/functional.py b/django/utils/functional.py index c0d19093fcd..ee0a1953ddf 100644 --- a/django/utils/functional.py +++ b/django/utils/functional.py @@ -128,6 +128,11 @@ def lazy(func, *resultclasses): else: return func(*self.__args, **self.__kw) + def __str__(self): + # object defines __str__(), so __prepare_class__() won't overload + # a __str__() method from the proxied class. + return str(self.__cast()) + def __ne__(self, other): if isinstance(other, Promise): other = other.__cast() diff --git a/tests/utils_tests/test_functional.py b/tests/utils_tests/test_functional.py index 5f7687edf52..135e8da0ed3 100644 --- a/tests/utils_tests/test_functional.py +++ b/tests/utils_tests/test_functional.py @@ -1,5 +1,9 @@ +# -*- encoding: utf-8 -*- +from __future__ import unicode_literals + import unittest +from django.utils import six from django.utils.functional import cached_property, lazy, lazy_property @@ -54,6 +58,26 @@ class FunctionalTestCase(unittest.TestCase): self.assertRaises(NotImplementedError, lambda: A().do) self.assertEqual(B().do, 'DO IT') + def test_lazy_object_to_string(self): + + class Klazz(object): + if six.PY3: + def __str__(self): + return "Î am ā Ǩlâzz." + + def __bytes__(self): + return b"\xc3\x8e am \xc4\x81 binary \xc7\xa8l\xc3\xa2zz." + else: + def __unicode__(self): + return "Î am ā Ǩlâzz." + + def __str__(self): + return b"\xc3\x8e am \xc4\x81 binary \xc7\xa8l\xc3\xa2zz." + + t = lazy(lambda: Klazz(), Klazz)() + self.assertEqual(six.text_type(t), "Î am ā Ǩlâzz.") + self.assertEqual(six.binary_type(t), b"\xc3\x8e am \xc4\x81 binary \xc7\xa8l\xc3\xa2zz.") + def test_cached_property(self): """ Test that cached_property caches its value,