Merge branch 'allow-periods-in-dict' of https://github.com/mcsimps2/mongoengine into mcsimps2-allow-periods-in-dict

AUTHORS

@@ -254,3 +254,4 @@ that much better:
  * Yurii Andrieiev (https://github.com/yandrieiev)
  * Filip Kucharczyk (https://github.com/Pacu2)
  * Eric Timmons (https://github.com/daewok)
+ * Matthew Simpson (https://github.com/mcsimps2)

mongoengine/fields.py

@@ -41,6 +41,7 @@ from mongoengine.common import _import_class
 from mongoengine.connection import DEFAULT_CONNECTION_NAME, get_db
 from mongoengine.document import Document, EmbeddedDocument
 from mongoengine.errors import DoesNotExist, InvalidQueryError, ValidationError
+from mongoengine.mongodb_support import MONGODB_36, get_mongodb_version
 from mongoengine.python_support import StringIO
 from mongoengine.queryset import DO_NOTHING
 from mongoengine.queryset.base import BaseQuerySet
@@ -1051,6 +1052,15 @@ def key_has_dot_or_dollar(d):
             return True
 
 
+def key_starts_with_dollar(d):
+    """Helper function to recursively determine if any key in a
+    dictionary starts with a dollar
+    """
+    for k, v in d.items():
+        if (k.startswith("$")) or (isinstance(v, dict) and key_starts_with_dollar(v)):
+            return True
+
+
 class DictField(ComplexBaseField):
     """A dictionary field that wraps a standard Python dictionary. This is
     similar to an embedded document, but the structure is not defined.
@@ -1077,11 +1087,18 @@ class DictField(ComplexBaseField):
         if key_not_string(value):
             msg = "Invalid dictionary key - documents must have only string keys"
             self.error(msg)
-        if key_has_dot_or_dollar(value):
+
+        curr_mongo_ver = get_mongodb_version()
+
+        if curr_mongo_ver < MONGODB_36 and key_has_dot_or_dollar(value):
             self.error(
                 'Invalid dictionary key name - keys may not contain "."'
                 ' or startswith "$" characters'
             )
+        elif curr_mongo_ver >= MONGODB_36 and key_starts_with_dollar(value):
+            self.error(
+                'Invalid dictionary key name - keys may not startswith "$" characters'
+            )
         super(DictField, self).validate(value)
 
     def lookup_member(self, member_name):

tests/fields/test_dict_field.py

@@ -3,6 +3,7 @@ import pytest
 
 from mongoengine import *
 from mongoengine.base import BaseDict
+from mongoengine.mongodb_support import MONGODB_36, get_mongodb_version
 
 from tests.utils import MongoDBTestCase, get_as_pymongo
 
@@ -43,11 +44,7 @@ class TestDictField(MongoDBTestCase):
         with pytest.raises(ValidationError):
             post.validate()
 
-        post.info = {"the.title": "test"}
-        with pytest.raises(ValidationError):
-            post.validate()
-
-        post.info = {"nested": {"the.title": "test"}}
+        post.info = {"$title.test": "test"}
         with pytest.raises(ValidationError):
             post.validate()
 
@@ -55,6 +52,20 @@ class TestDictField(MongoDBTestCase):
         with pytest.raises(ValidationError):
             post.validate()
 
+        post.info = {"nested": {"the.title": "test"}}
+        if get_mongodb_version() < MONGODB_36:
+            with pytest.raises(ValidationError):
+                post.validate()
+        else:
+            post.validate()
+
+        post.info = {"dollar_and_dot": {"te$st.test": "test"}}
+        if get_mongodb_version() < MONGODB_36:
+            with pytest.raises(ValidationError):
+                post.validate()
+        else:
+            post.validate()
+
         post.info = {"title": "test"}
         post.save()