decorators: test and fix copy_cache, bug introduced in 1411:2f974a847d7e

2 files changed, 24 insertions, 9 deletions

diff --git a/decorators.py b/decorators.py
index 6b73440..39144d1 100644
--- a/decorators.py
+++ b/decorators.py
@@ -62,7 +62,7 @@ class _SingleValueCache(object):
     def closure(self):
         def wrapped(*args, **kwargs):
             return self.__call__(*args, **kwargs)
-        wrapped.clear = self.clear
+        wrapped.cache_obj = self
         try:
             wrapped.__doc__ = self.callable.__doc__
             wrapped.__name__ = self.callable.__name__
@@ -116,6 +116,13 @@ def cached(callableobj=None, keyarg=None, **kwargs):
     else:
         return decorator(callableobj)
 
+def get_cache_impl(obj, funcname):
+    cls = obj.__class__
+    member = getattr(cls, funcname)
+    if isinstance(member, property):
+        member = member.fget
+    return member.cache_obj
+
 def clear_cache(obj, funcname):
     """Clear a cache handled by the :func:`cached` decorator. If 'x' class has
     @cached on its method `foo`, type
@@ -124,17 +131,13 @@ def clear_cache(obj, funcname):
 
     to purge this method's cache on the instance.
     """
-    cls = obj.__class__
-    member = getattr(cls, funcname)
-    if isinstance(member, property):
-        member = member.fget
-    member.clear(obj)
+    get_cache_impl(obj, funcname).clear(obj)
 
 def copy_cache(obj, funcname, cacheobj):
     """Copy cache for <funcname> from cacheobj to obj."""
-    cache = getattr(obj, funcname).cacheattr
+    cacheattr = get_cache_impl(obj, funcname).cacheattr
     try:
-        setattr(obj, cache, cacheobj.__dict__[cache])
+        setattr(obj, cacheattr, cacheobj.__dict__[cacheattr])
     except KeyError:
         pass
 
diff --git a/test/unittest_decorators.py b/test/unittest_decorators.py
index 1f92d55..75261c9 100644
--- a/test/unittest_decorators.py
+++ b/test/unittest_decorators.py
@@ -19,7 +19,7 @@
 """
 
 from logilab.common.testlib import TestCase, unittest_main
-from logilab.common.decorators import monkeypatch, cached, clear_cache
+from logilab.common.decorators import monkeypatch, cached, clear_cache, copy_cache
 
 class DecoratorsTC(TestCase):
 
@@ -114,6 +114,18 @@ class DecoratorsTC(TestCase):
         clear_cache(foo, 'foo')
         self.assertFalse(hasattr(foo, '_foo'))
 
+    def test_copy_cache(self):
+        class Foo(object):
+            @cached(cacheattr=u'_foo')
+            def foo(self, args):
+                """ what's up doc ? """
+        foo = Foo()
+        foo.foo(1)
+        self.assertEqual(foo._foo, {(1,): None})
+        foo2 = Foo()
+        self.assertFalse(hasattr(foo2, '_foo'))
+        copy_cache(foo2, 'foo', foo)
+        self.assertEqual(foo2._foo, {(1,): None})
 
 if __name__ == '__main__':
     unittest_main()