Fix deepcopy issue with classes deriving from dicts (mongomock#52)

Author: vmalloc

Makefile

@@ -0,0 +1,2 @@
+test:
+	nosetests

mongomock/__init__.py

@@ -141,15 +141,19 @@ def insert(self, data):
         if isinstance(data, list):
             return [self._insert(element) for element in data]
         return self._insert(data)
+
     def _insert(self, data):
-        if not '_id' in data:
+        if '_id' not in data:
             data['_id'] = ObjectId()
         object_id = data['_id']
         if object_id in self._documents:
             raise DuplicateKeyError("Duplicate Key Error", 11000)
-        self._documents[object_id] = copy.deepcopy(data)
+        self._documents[object_id] = self._internalize_dict(data)
         return object_id
 
+    def _internalize_dict(self, d):
+        return dict((k, copy.deepcopy(v)) for k, v in iteritems(d))
+
     def _has_key(self, doc, key):
         return key in doc
 

tests/test__mongomock.py

@@ -88,6 +88,21 @@ def test__getting_collection_via_getattr(self):
         self.assertIs(col1, self.db['some_collection_here'])
         self.assertIsInstance(col1, mongomock.Collection)
 
+    def test__save_class_deriving_from_dict(self):
+        # See https://github.com/vmalloc/mongomock/issues/52
+        class Document(dict):
+            def __init__(self, collection):
+                self.collection = collection
+                super(Document, self).__init__()
+                self.save()
+
+            def save(self):
+                self.collection.save(self)
+
+        doc = Document(self.db.collection)
+        self.assertIn("_id", doc)
+        self.assertNotIn("collection", doc)
+
     def test__getting_collection_via_getitem(self):
         col1 = self.db['some_collection_here']
         col2 = self.db['some_collection_here']