Merge pull request #5 from conversocial/dev-equality

feat: noticket - Update Document __eq__/__ne__ to return NotImplemented

Author: iainb

mongoengine/__init__.py

@@ -12,7 +12,7 @@
 __all__ = (document.__all__ + fields.__all__ + connection.__all__ +
            queryset.__all__ + signals.__all__)
 
-VERSION = (0, 6, 20)
+VERSION = (0, 6, 21)
 
 
 def get_version():

mongoengine/base.py

@@ -1143,12 +1143,14 @@ def __str__(self):
 
     def __eq__(self, other):
         if isinstance(other, self.__class__) and hasattr(other, 'id'):
-            if self.id == other.id:
-                return True
-        return False
+            return self.id == other.id
+        return NotImplemented
 
     def __ne__(self, other):
-        return not self.__eq__(other)
+        res = self.__eq__(other)
+        if res == NotImplemented:
+            return NotImplemented
+        return not res
 
     def __hash__(self):
         if self.pk is None:

tests/document.py

@@ -2279,5 +2279,45 @@ def __str__(self):
                                         }
                                     ) ]), "1,2")
 
+
+    def test_document_equality(self):
+        class A(Document):
+            name = StringField()
+
+        class B(Document):
+            name = StringField()
+
+        class SomethingElse(object):
+            def __init__(self, id, name):
+                self.id = id
+                self.name = name
+
+        a = A(id=1, name="BOOK")
+        a_ = A(id=1, name="BOOK")
+        b = B(id=1, name="BOOK")
+        somethingElse = SomethingElse(id=1, name="BOOK")
+
+        # ensure __eq__ returns NotImplemented
+        self.assertEqual(a.__eq__(a_), True)
+        self.assertEqual(a.__eq__(b), NotImplemented)
+        self.assertEqual(a.__eq__(somethingElse), NotImplemented)
+
+        # test equality
+        self.assertTrue(a == a_)
+        self.assertFalse(a == b)
+        self.assertFalse(a == somethingElse)
+
+        # test __ne__ returns NotImplemented
+        self.assertEqual(a.__ne__(a_), False)
+        self.assertEqual(a.__ne__(b), NotImplemented)
+        self.assertEqual(a.__ne__(somethingElse), NotImplemented)
+
+        # test not equal
+        self.assertFalse(a != a_)
+        self.assertTrue(a != b)
+        self.assertTrue(a != somethingElse)
+
+
+
 if __name__ == '__main__':
     unittest.main()