Fixed #112 and cleaned up error reporting when loading extensions.

markdown/__init__.py

@@ -37,6 +37,7 @@
 import codecs
 import sys
 import logging
+import warnings
 import util
 from preprocessors import build_preprocessors
 from blockprocessors import build_block_parser
@@ -163,10 +164,10 @@ def registerExtensions(self, extensions, configs):
             if isinstance(ext, basestring):
                 ext = self.build_extension(ext, configs.get(ext, []))
             if isinstance(ext, Extension):
-                # might raise NotImplementedError, but that's the extension author's problem
                 ext.extendMarkdown(self, globals())
             elif ext is not None:
-                raise ValueError('Extension "%s.%s" must be of type: "markdown.Extension".' \
+                raise TypeError(
+                    'Extension "%s.%s" must be of type: "markdown.Extension"'
                     % (ext.__class__.__module__, ext.__class__.__name__))
 
         return self
@@ -200,19 +201,22 @@ def build_extension(self, ext_name, configs = []):
             module_name_old_style = '_'.join(['mdx', ext_name])
             try: # Old style (mdx_<extension>)
                 module = __import__(module_name_old_style)
-            except ImportError:
-                logger.warn("Failed loading extension '%s' from '%s' or '%s'"
-                    % (ext_name, module_name, module_name_old_style))
-                # Return None so we don't try to initiate none-existant extension
-                return None
+            except ImportError, e:
+                message = "Failed loading extension '%s' from '%s' or '%s'" \
+                    % (ext_name, module_name, module_name_old_style)
+                e.args = (message,) + e.args[1:]
+                raise
 
         # If the module is loaded successfully, we expect it to define a
         # function called makeExtension()
         try:
             return module.makeExtension(configs.items())
         except AttributeError, e:
-            logger.warn("Failed to initiate extension '%s': %s" % (ext_name, e))
-            return None
+            message = e.args[0]
+            message = "Failed to initiate extension " \
+                      "'%s': %s" % (ext_name, message)
+            e.args = (message,) + e.args[1:]
+            raise
 
     def registerExtension(self, extension):
         """ This gets called by the extension """

tests/test_apis.py

@@ -245,18 +245,18 @@ def testBadOutputFormat(self):
 
     def testLoadExtensionFailure(self):
         """ Test failure of an extension to load. """
-        self.assertRaises(ValueError, 
+        self.assertRaises(ImportError, 
                         markdown.Markdown, extensions=['non_existant_ext']) 
 
     def testLoadBadExtension(self):
         """ Test loading of an Extension with no makeExtension function. """
         _create_fake_extension(name='fake', has_factory_func=False)
-        self.assertRaises(ValueError, markdown.Markdown, extensions=['fake'])
+        self.assertRaises(AttributeError, markdown.Markdown, extensions=['fake'])
 
     def testNonExtension(self):
         """ Test loading a non Extension object as an extension. """
         _create_fake_extension(name='fake', is_wrong_type=True)
-        self.assertRaises(ValueError, markdown.Markdown, extensions=['fake'])
+        self.assertRaises(TypeError, markdown.Markdown, extensions=['fake'])
 
     def testBaseExtention(self):
         """ Test that the base Extension class will raise NotImplemented. """