[modutils] deprecate modpath_from_file

The method will likely fail if there somes symlinks in your python environment
and will certainly fail on a file that isn't in sys.path (like custom importers
using sys.meta_path).

2 files changed, 11 insertions, 3 deletions

diff --git a/logilab/common/modutils.py b/logilab/common/modutils.py
index 31b5b27..030cfa3 100644
--- a/logilab/common/modutils.py
+++ b/logilab/common/modutils.py
@@ -49,6 +49,7 @@ except ImportError:
 ZIPFILE = object()
 
 from logilab.common import STD_BLACKLIST, _handle_blacklist
+from logilab.common.deprecation import deprecated
 
 # Notes about STD_LIB_DIR
 # Consider arch-specific installation for STD_LIB_DIR definition
@@ -234,8 +235,11 @@ def _path_from_filename(filename):
         return filename
 
 
+@deprecated('you should avoid using modpath_from_file()')
 def modpath_from_file(filename, extrapath=None):
-    """given a file path return the corresponding splitted module's name
+    """DEPRECATED: doens't play well with symlinks and sys.meta_path
+
+    Given a file path return the corresponding splitted module's name
     (i.e name of a module or package splitted on '.')
 
     :type filename: str
diff --git a/test/unittest_modutils.py b/test/unittest_modutils.py
index d1fcaf9..ec2a5c8 100644
--- a/test/unittest_modutils.py
+++ b/test/unittest_modutils.py
@@ -21,6 +21,7 @@ unit tests for module modutils (module manipulation utilities)
 
 import doctest
 import sys
+import warnings
 try:
     __file__
 except NameError:
@@ -117,8 +118,11 @@ class modpath_from_file_tc(ModutilsTestCase):
     """ given an absolute file path return the python module's path as a list """
 
     def test_knownValues_modpath_from_file_1(self):
-        self.assertEqual(modutils.modpath_from_file(modutils.__file__),
-                         ['logilab', 'common', 'modutils'])
+        with warnings.catch_warnings(record=True) as warns:
+            self.assertEqual(modutils.modpath_from_file(modutils.__file__),
+                             ['logilab', 'common', 'modutils'])
+            self.assertIn('you should avoid using modpath_from_file()',
+                          [str(w.message) for w in warns])
 
     def test_knownValues_modpath_from_file_2(self):
         self.assertEqual(modutils.modpath_from_file('unittest_modutils.py',