Lib/test/test_property.py

   1 # Test case for property
   2 # more tests are in test_descr
   3
   4 import unittest
   5 from test.test_support import run_unittest
   6
   7 class PropertyBase(Exception):
   8     pass
   9
  10 class PropertyGet(PropertyBase):
  11     pass
  12
  13 class PropertySet(PropertyBase):
  14     pass
  15
  16 class PropertyDel(PropertyBase):
  17     pass
  18
  19 class BaseClass(object):
  20     def __init__(self):
  21         self._spam = 5
  22
  23     @property
  24     def spam(self):
  25         """BaseClass.getter"""
  26         return self._spam
  27
  28     @spam.setter
  29     def spam(self, value):
  30         self._spam = value
  31
  32     @spam.deleter
  33     def spam(self):
  34         del self._spam
  35
  36 class SubClass(BaseClass):
  37
  38     @BaseClass.spam.getter
  39     def spam(self):
  40         """SubClass.getter"""
  41         raise PropertyGet(self._spam)
  42
  43     @spam.setter
  44     def spam(self, value):
  45         raise PropertySet(self._spam)
  46
  47     @spam.deleter
  48     def spam(self):
  49         raise PropertyDel(self._spam)
  50
  51 class PropertyDocBase(object):
  52     _spam = 1
  53     def _get_spam(self):
  54         return self._spam
  55     spam = property(_get_spam, doc="spam spam spam")
  56
  57 class PropertyDocSub(PropertyDocBase):
  58     @PropertyDocBase.spam.getter
  59     def spam(self):
  60         """The decorator does not use this doc string"""
  61         return self._spam
  62
  63 class PropertyTests(unittest.TestCase):
  64     def test_property_decorator_baseclass(self):
  65         # see #1620
  66         base = BaseClass()
  67         self.assertEqual(base.spam, 5)
  68         self.assertEqual(base._spam, 5)
  69         base.spam = 10
  70         self.assertEqual(base.spam, 10)
  71         self.assertEqual(base._spam, 10)
  72         delattr(base, "spam")
  73         self.assert_(not hasattr(base, "spam"))
  74         self.assert_(not hasattr(base, "_spam"))
  75         base.spam = 20
  76         self.assertEqual(base.spam, 20)
  77         self.assertEqual(base._spam, 20)
  78         self.assertEqual(base.__class__.spam.__doc__, "BaseClass.getter")
  79
  80     def test_property_decorator_subclass(self):
  81         # see #1620
  82         sub = SubClass()
  83         self.assertRaises(PropertyGet, getattr, sub, "spam")
  84         self.assertRaises(PropertySet, setattr, sub, "spam", None)
  85         self.assertRaises(PropertyDel, delattr, sub, "spam")
  86         self.assertEqual(sub.__class__.spam.__doc__, "SubClass.getter")
  87
  88     def test_property_decorator_doc(self):
  89         base = PropertyDocBase()
  90         sub = PropertyDocSub()
  91         self.assertEqual(base.__class__.spam.__doc__, "spam spam spam")
  92         self.assertEqual(sub.__class__.spam.__doc__, "spam spam spam")
  93
  94 def test_main():
  95     run_unittest(PropertyTests)
  96
  97 if __name__ == '__main__':
  98     test_main()