Automatically create missing collections

tests/test_cli.py

@@ -278,18 +278,19 @@ def test_collections_cache_invalidation(tmpdir):
     [pair foobar]
     a = foo
     b = bar
+    collections = a, b, c
     ''').format(str(tmpdir)))
 
     foo = tmpdir.mkdir('foo')
-    tmpdir.mkdir('bar')
-    foo.join('itemone.txt').write('UID:itemone')
+    bar = tmpdir.mkdir('bar')
+    foo.mkdir('a').join('itemone.txt').write('UID:itemone')
 
     runner = CliRunner()
     result = runner.invoke(cli.app, ['sync'],
                            env={'VDIRSYNCER_CONFIG': str(cfg)})
     assert not result.exception
 
-    rv = tmpdir.join('bar').listdir()
+    rv = bar.join('a').listdir()
     assert len(rv) == 1
     assert rv[0].basename == 'itemone.txt'
 
@@ -310,14 +311,16 @@ def test_collections_cache_invalidation(tmpdir):
     [pair foobar]
     a = foo
     b = bar
+    collections = a, b, c
     ''').format(str(tmpdir)))
 
     tmpdir.join('status').remove()
+    bar2 = tmpdir.mkdir('bar2')
     result = runner.invoke(cli.app, ['sync'],
                            env={'VDIRSYNCER_CONFIG': str(cfg)})
     assert not result.exception
 
-    rv = tmpdir.join('bar').listdir()
-    rv2 = tmpdir.join('bar2').listdir()
+    rv = bar.join('a').listdir()
+    rv2 = tmpdir.join('bar2').join('a').listdir()
     assert len(rv) == len(rv2) == 1
     assert rv[0].basename == rv2[0].basename == 'itemone.txt'

vdirsyncer/cli.py

@@ -191,20 +191,28 @@ def _discover_from_config(config):
                 rv[args['collection']] = args
             return rv
 
-    def _get_coll(discovered, collection, storage_name):
+    def _get_coll(discovered, collection, storage_name, config):
         try:
             return discovered[collection]
         except KeyError:
-            raise CliError(
-                'Unable to find collection {collection!r} for storage '
-                '{storage_name!r}.\n For pair {pair_name!r}, you wanted to '
-                'use the collections {shortcut!r}, which yielded '
-                '{collection!r} (amongst others). Vdirsyncer was unable to '
-                'find an equivalent collection for the other storage.'.format(
-                    collection=collection, shortcut=shortcut,
-                    storage_name=storage_name, pair_name=pair_name
+            storage_type = config['type']
+            cls, config = storage_class_from_config(config)
+            try:
+                rv = cls.join_collection(collection=collection, **config)
+                rv['type'] = storage_type
+                return rv
+            except NotImplementedError:
+                raise CliError(
+                    'Unable to find collection {collection!r} for storage '
+                    '{storage_name!r}.\n For pair {pair_name!r}, you wanted '
+                    'to use the collections {shortcut!r}, which yielded '
+                    '{collection!r} (amongst others). Vdirsyncer was unable '
+                    'to find an equivalent collection for the other '
+                    'storage.'.format(
+                        collection=collection, shortcut=shortcut,
+                        storage_name=storage_name, pair_name=pair_name
+                    )
                 )
-            )
 
     shortcuts = set(_parse_old_config_list_value(pair_options, 'collections'))
     if not shortcuts:
@@ -221,8 +229,8 @@ def _get_coll(discovered, collection, storage_name):
             collections = [shortcut]
 
         for collection in collections:
-            a_args = _get_coll(a_discovered, collection, name_a)
-            b_args = _get_coll(b_discovered, collection, name_b)
+            a_args = _get_coll(a_discovered, collection, name_a, config_a)
+            b_args = _get_coll(b_discovered, collection, name_b, config_b)
             yield collection, a_args, b_args
 
 

vdirsyncer/storage/base.py

@@ -89,6 +89,13 @@ class to obtain a storage instance pointing to this collection. It
         '''
         raise NotImplementedError()
 
+    @classmethod
+    def join_collection(cls, collection, **kwargs):
+        '''Append the collection to the URL or path specified in ``**kwargs``
+        and return the new arguments.
+        '''
+        raise NotImplementedError()
+
     def __repr__(self):
         return self.instance_name or '<{}(**{})>'.format(
             self.__class__.__name__,

vdirsyncer/storage/filesystem.py

@@ -57,6 +57,11 @@ def discover(cls, path, **kwargs):
                             **kwargs)
                 yield args
 
+    @classmethod
+    def join_collection(cls, collection, **kwargs):
+        kwargs['path'] = os.path.join(kwargs['path'], collection)
+        return kwargs
+
     def _get_filepath(self, href):
         return os.path.join(self.path, href)