1 files changed, 44 insertions, 6 deletions
diff --git a/logilab/common/deprecation.py b/logilab/common/deprecation.py
index 5dc23f7..ff6dc7c 100644
--- a/logilab/common/deprecation.py
+++ b/logilab/common/deprecation.py
@@ -22,7 +22,45 @@ __docformat__ = "restructuredtext en"
 import os
 import sys
 from warnings import warn
-from functools import wraps
+from functools import WRAPPER_ASSIGNMENTS, WRAPPER_UPDATES, wraps
+
+
+def lazy_wraps(wrapped):
+    """
+    This is the equivalent of the @wraps decorator of functools except it won't
+    try to grabs attributes of the targeted function on decoration but on access.
+
+    This is needed because of logilab.common.modutils.LazyObject.
+
+    Indeed: if you try to decorate a LazyObject with @wraps, wraps will try to
+    access attributes of LazyObject and this will trigger the attempt to import
+    the module decorated by LazyObject which you don't want to do when you just
+    want to mark this LazyObject has been a deprecated objet that you only
+    wants to trigger if the user try to use it.
+
+    Usage: like @wraps()
+
+    >>> @lazy_wraps(function)
+    >>> def wrapper(*args, **kwargs): ...
+    """
+
+    def update_wrapper_attributes(wrapper):
+        def __getattribute__(self, attribute):
+            if attribute in WRAPPER_ASSIGNMENTS:
+                return getattr(wrapped, attribute)
+
+            return super(self.__class__, self).__getattribute__(attribute)
+
+        wrapper.__getattribute__ = __getattribute__
+
+        for attribute in WRAPPER_UPDATES:
+            getattr(wrapper, attribute).update(getattr(wrapped, attribute, {}))
+
+        wrapper.__wrapped__ = wrapped
+
+        return wrapper
+
+    return update_wrapper_attributes
 
 
 class DeprecationWrapper(object):
@@ -160,12 +198,12 @@ def callable_deprecated(reason=None, version=None, stacklevel=2):
     """
 
     def decorator(func):
-        message = reason or 'The function "%s" is deprecated'
-        if "%s" in message:
-            message %= func.__name__
-
-        @wraps(func)
+        @lazy_wraps(func)
         def wrapped(*args, **kwargs):
+            message = reason or 'The function "%s" is deprecated'
+            if "%s" in message:
+                message %= func.__name__
+
             send_warning(message, version, stacklevel + 1, module_name=func.__module__)
             return func(*args, **kwargs)