[decorators] fix docstring handling and add a test #23389

2 files changed, 18 insertions, 2 deletions

diff --git a/decorators.py b/decorators.py
index 9e5e085..cb3070f 100644
--- a/decorators.py
+++ b/decorators.py
@@ -14,7 +14,6 @@ import sys, re
 
 def cached(callableobj, keyarg=None):
     """Simple decorator to cache result of method call."""
-    #print callableobj, keyarg, callableobj.func_code.co_argcount
     if callableobj.func_code.co_argcount == 1 or keyarg == 0:
 
         def cache_wrapper1(self, *args):
@@ -27,6 +26,7 @@ def cached(callableobj, keyarg=None):
                 value = callableobj(self, *args)
                 setattr(self, cache, value)
                 return value
+        cache_wrapper1.__doc__ = callableobj.__doc__
         return cache_wrapper1
 
     elif keyarg:
@@ -47,6 +47,7 @@ def cached(callableobj, keyarg=None):
                 #print 'miss', self, cache, key
                 _cache[key] = callableobj(self, *args, **kwargs)
             return _cache[key]
+        cache_wrapper2.__doc__ = callableobj.__doc__
         return cache_wrapper2
 
     def cache_wrapper3(self, *args):
@@ -64,6 +65,7 @@ def cached(callableobj, keyarg=None):
             #print 'miss'
             _cache[args] = callableobj(self, *args)
         return _cache[args]
+    cache_wrapper3.__doc__ = callableobj.__doc__
     return cache_wrapper3
 
 def clear_cache(obj, funcname):
diff --git a/test/unittest_decorators.py b/test/unittest_decorators.py
index b2fd8b5..942fe12 100644
--- a/test/unittest_decorators.py
+++ b/test/unittest_decorators.py
@@ -2,7 +2,7 @@
 """
 
 from logilab.common.testlib import TestCase, unittest_main
-from logilab.common.decorators import monkeypatch
+from logilab.common.decorators import monkeypatch, cached
 
 class DecoratorsTC(TestCase):
 
@@ -26,6 +26,20 @@ class DecoratorsTC(TestCase):
         inst = MyClass()
         self.assertEquals(inst.foo(4), 16)
 
+    def test_cached_preserves_docstrings(self):
+        class Foo(object):
+            @cached
+            def foo(self):
+                """ what's up doc ? """
+            def bar(self, zogzog):
+                """ what's up doc ? """
+            bar = cached(bar, 1)
+            @cached
+            def quux(self, zogzog):
+                """ what's up doc ? """
+        self.assertEquals(Foo.foo.__doc__, """ what's up doc ? """)
+        self.assertEquals(Foo.bar.__doc__, """ what's up doc ? """)
+        self.assertEquals(Foo.quux.__doc__, """ what's up doc ? """)
 
 if __name__ == '__main__':
     unittest_main()