Improve errorhandling for enduser

tests/storage/test_http.py

@@ -6,6 +6,7 @@ from requests import Response
 
 from tests import normalize_item
 
+from vdirsyncer.exceptions import UserError
 from vdirsyncer.storage.http import HttpStorage, prepare_auth
 
 
@@ -107,7 +108,7 @@ def test_prepare_auth_guess(monkeypatch, auth):
 
     monkeypatch.delattr(requests_toolbelt.auth.guess, 'GuessAuth')
 
-    with pytest.raises(RuntimeError) as excinfo:
+    with pytest.raises(UserError) as excinfo:
         prepare_auth(auth, 'user', 'pwd')
 
     assert 'requests_toolbelt is too old' in str(excinfo.value).lower()

vdirsyncer/cli/utils.py

@@ -495,8 +495,9 @@ def handle_storage_init_error(cls, config):
             .format(cls.storage_name, u', '.join(invalid)))
 
     if not problems:
-        cli_logger.exception('')
-        problems.append('Internal error, see above.')
+        if not isinstance(e, exceptions.UserError):
+            cli_logger.exception('')
+        problems.append(str(e))
 
     raise CliError(u'Failed to initialize {}'.format(config['instance_name']),
                    problems=problems)

vdirsyncer/exceptions.py

@@ -17,6 +17,11 @@ class Error(Exception):
         super(Error, self).__init__(*args)
 
 
+class UserError(Error, ValueError):
+    '''Wrapper exception to be used to signify the traceback should not be
+    shown to the user.'''
+
+
 class CollectionNotFound(Error):
     '''Collection not found'''
 

vdirsyncer/storage/base.py

@@ -77,7 +77,7 @@ class Storage(with_metaclass(StorageMeta)):
         if read_only is None:
             read_only = self.read_only
         if self.read_only and not read_only:
-            raise ValueError('This storage can only be read-only.')
+            raise exceptions.UserError('This storage can only be read-only.')
         self.read_only = bool(read_only)
 
         if collection and instance_name:

vdirsyncer/storage/dav.py

@@ -591,12 +591,12 @@ class CaldavStorage(DavStorage):
                  item_types=(), **kwargs):
         super(CaldavStorage, self).__init__(**kwargs)
         if not isinstance(item_types, (list, tuple)):
-            raise ValueError('item_types must be a list.')
+            raise exceptions.UserError('item_types must be a list.')
 
         self.item_types = tuple(item_types)
         if (start_date is None) != (end_date is None):
-            raise ValueError('If start_date is given, '
-                             'end_date has to be given too.')
+            raise exceptions.UserError('If start_date is given, '
+                                       'end_date has to be given too.')
         elif start_date is not None and end_date is not None:
             namespace = dict(datetime.__dict__)
             namespace['start_date'] = self.start_date = \

vdirsyncer/storage/http.py

@@ -1,7 +1,7 @@
 # -*- coding: utf-8 -*-
 
 from .base import Item, Storage
-from ..exceptions import NotFoundError
+from .. import exceptions
 from ..utils import expand_path
 from ..utils.compat import iteritems, text_type, urlparse
 from ..utils.http import request
@@ -22,16 +22,19 @@ def prepare_auth(auth, username, password):
             try:
                 from requests_toolbelt.auth.guess import GuessAuth
             except ImportError:
-                raise RuntimeError('Your version of requests_toolbelt is too '
-                                   'old for `guess` authentication. At least '
-                                   'version 0.4.0 is required.')
+                raise exceptions.UserError(
+                    'Your version of requests_toolbelt is too '
+                    'old for `guess` authentication. At least '
+                    'version 0.4.0 is required.'
+                )
             else:
                 return GuessAuth(username, password)
         else:
-            raise ValueError('Unknown authentication method: {}'.format(auth))
+            raise exceptions.UserError('Unknown authentication method: {}'
+                                       .format(auth))
     elif auth:
-        raise ValueError('For {} authentication, you need to specify username '
-                         'and password.'.format(auth))
+        raise exceptions.UserError('You need to specify username and password '
+                                   'for {} authentication.'.format(auth))
     else:
         return None
 
@@ -40,20 +43,20 @@ def prepare_verify(verify, verify_fingerprint):
     if isinstance(verify, (text_type, bytes)):
         verify = expand_path(verify)
     elif not isinstance(verify, bool):
-        raise ValueError('Invalid value for verify ({}), '
-                         'must be a path to a PEM-file or boolean.'
-                         .format(verify))
+        raise exceptions.UserError('Invalid value for verify ({}), '
+                                   'must be a path to a PEM-file or boolean.'
+                                   .format(verify))
 
     if verify_fingerprint is not None:
         if not isinstance(verify_fingerprint, str):
-            raise ValueError('Invalid value for verify_fingerprint ({}), '
-                             'must be a string or null.'
-                             .format(verify_fingerprint))
+            raise exceptions.UserError('Invalid value for verify_fingerprint '
+                                       '({}), must be a string or null.'
+                                       .format(verify_fingerprint))
         verify = False
     elif not verify:
-        raise ValueError('verify = false is forbidden. Consider setting '
-                         'verify_fingerprint instead, which also disables '
-                         'validation against CAs.')
+        raise exceptions.UserError('verify = false is forbidden. Consider '
+                                   'setting verify_fingerprint instead, which '
+                                   'also disables validation against CAs.')
 
     return {
         'verify': verify,
@@ -161,4 +164,4 @@ class HttpStorage(Storage):
         try:
             return self._items[href]
         except KeyError:
-            raise NotFoundError(href)
+            raise exceptions.NotFoundError(href)

vdirsyncer/storage/memory.py

@@ -18,7 +18,8 @@ class MemoryStorage(Storage):
 
     def __init__(self, fileext='', **kwargs):
         if kwargs.get('collection') is not None:
-            raise ValueError('MemoryStorage does not support collections.')
+            raise exceptions.UserError('MemoryStorage does not support '
+                                       'collections.')
         self.items = {}  # href => (etag, item)
         self.fileext = fileext
         super(MemoryStorage, self).__init__(**kwargs)

vdirsyncer/storage/singlefile.py

@@ -77,8 +77,10 @@ class SingleFileStorage(Storage):
 
         collection = kwargs.get('collection')
         if collection is not None:
-            raise ValueError('collection is not a valid argument for {}'
-                             .format(type(self).__name__))
+            raise exceptions.UserError(
+                'collection is not a valid argument for {}'
+                .format(type(self).__name__)
+            )
 
         checkfile(path, create=False)
 

vdirsyncer/sync.py

@@ -278,8 +278,8 @@ def _action_conflict_resolve(ident):
             sync_logger.info('...{} wins.'.format(b.storage))
             _action_update(ident, b, a)(a, b, conflict_resolution)
         else:
-            raise ValueError('Invalid conflict resolution mode: {}'
-                             .format(conflict_resolution))
+            raise exceptions.UserError('Invalid conflict resolution mode: {}'
+                                       .format(conflict_resolution))
 
     return inner