Maintenance: cached property nesting (#49)

* simplified cached_property

Author: maxfischer2781

asyncstdlib/functools.py

@@ -116,14 +116,9 @@ def __get__(self, instance, owner):
         return self._get_attribute(instance)
 
     async def _get_attribute(self, instance) -> T:
-        attributes = instance.__dict__
-        try:
-            return attributes[self._name]
-        except KeyError:
-            value = await self.__wrapped__(instance)
-            if self._name not in attributes:
-                attributes[self._name] = AwaitableValue(value)
-            return value
+        value = await self.__wrapped__(instance)
+        instance.__dict__[self._name] = AwaitableValue(value)
+        return value
 
 
 cached_property = CachedProperty

unittests/test_functools.py

@@ -35,12 +35,11 @@ class Pair:
             __slots__ = "a", "b"
 
             def __init__(self, a, b):
-                self.a = a
-                self.b = b
+                pass  # pragma: no cover
 
             @a.cached_property
             async def total(self):
-                return self.a + self.b
+                pass  # pragma: no cover
 
 
 @multi_sync
@@ -62,7 +61,7 @@ async def check_increment(to):
     val = Value(0)
     await Schedule(check_increment(5), check_increment(12), check_increment(1337))
     assert (await val.cached) != 0
-    assert (await val.cached) == 5  # first value fetched
+    assert (await val.cached) == 1337  # last value fetched
 
 
 @sync