1 files changed, 66 insertions, 0 deletions
diff --git a/tests/utils/functional.py b/tests/utils/functional.py
new file mode 100644
index 0000000000..3bb50007c6
--- /dev/null
+++ b/tests/utils/functional.py
@@ -0,0 +1,66 @@
+from django.utils import unittest
+from django.utils.functional import lazy, lazy_property, cached_property
+
+
+class FunctionalTestCase(unittest.TestCase):
+    def test_lazy(self):
+        t = lazy(lambda: tuple(range(3)), list, tuple)
+        for a, b in zip(t(), range(3)):
+            self.assertEqual(a, b)
+
+    def test_lazy_base_class(self):
+        """Test that lazy also finds base class methods in the proxy object"""
+
+        class Base(object):
+            def base_method(self):
+                pass
+
+        class Klazz(Base):
+            pass
+
+        t = lazy(lambda: Klazz(), Klazz)()
+        self.assertTrue('base_method' in dir(t))
+
+    def test_lazy_property(self):
+
+        class A(object):
+
+            def _get_do(self):
+                raise NotImplementedError
+            def _set_do(self, value):
+                raise NotImplementedError
+            do = lazy_property(_get_do, _set_do)
+
+        class B(A):
+            def _get_do(self):
+                return "DO IT"
+
+        self.assertRaises(NotImplementedError, lambda: A().do)
+        self.assertEqual(B().do, 'DO IT')
+
+    def test_cached_property(self):
+        """
+        Test that cached_property caches its value,
+        and that it behaves like a property
+        """
+
+        class A(object):
+
+            @cached_property
+            def value(self):
+                return 1, object()
+
+        a = A()
+
+        # check that it is cached
+        self.assertEqual(a.value, a.value)
+
+        # check that it returns the right thing
+        self.assertEqual(a.value[0], 1)
+
+        # check that state isn't shared between instances
+        a2 = A()
+        self.assertNotEqual(a.value, a2.value)
+
+        # check that it behaves like a property when there's no instance
+        self.assertIsInstance(A.value, cached_property)