Fix duplicate extraction of from_dict (#204)

* Fix duplicate extraction of from_dict

* Update tests

* Remove unwanted code

Author: lmazuel

msrest/serialization.py

@@ -336,8 +336,8 @@ def from_dict(cls, data, key_extractors=None, content_type=None):
         """
         deserializer = Deserializer(cls._infer_class_models())
         deserializer.key_extractors = [
-            rest_key_case_insensitive_extractor,
             attribute_key_case_insensitive_extractor,
+            rest_key_case_insensitive_extractor,
             last_rest_key_case_insensitive_extractor
         ] if key_extractors is None else key_extractors
         return deserializer(cls.__name__, data, content_type=content_type)
@@ -1160,11 +1160,17 @@ def rest_key_case_insensitive_extractor(attr, attr_desc, data):
         return attribute_key_case_insensitive_extractor(key, None, working_data)
 
 def last_rest_key_extractor(attr, attr_desc, data):
+    """Extract the attribute in "data" based on the last part of the JSON path key.
+    """
     key = attr_desc['key']
     dict_keys = _FLATTEN.split(key)
     return attribute_key_extractor(dict_keys[-1], None, data)
 
 def last_rest_key_case_insensitive_extractor(attr, attr_desc, data):
+    """Extract the attribute in "data" based on the last part of the JSON path key.
+
+    This is the case insensitive version of "last_rest_key_extractor"
+    """
     key = attr_desc['key']
     dict_keys = _FLATTEN.split(key)
     return attribute_key_case_insensitive_extractor(dict_keys[-1], None, data)
@@ -1259,8 +1265,8 @@ def xml_key_extractor(attr, attr_desc, data):
 class Deserializer(object):
     """Response object model deserializer.
 
-    :param dict classes: Class type dictionary for deserializing
-     complex types.
+    :param dict classes: Class type dictionary for deserializing complex types.
+    :ivar list key_extractors: Ordered list of extractors to be used by this deserializer.
     """
 
     basic_types = {str: 'str', int: 'int', bool: 'bool', float: 'float'}
@@ -1375,7 +1381,15 @@ def _deserialize(self, target_obj, data):
                     found_value = key_extractor(attr, attr_desc, data)
                     if found_value is not None:
                         if raw_value is not None and raw_value != found_value:
-                            raise KeyError('Use twice the key: "{}"'.format(attr))
+                            msg = ("Ignoring extracted value '%s' from %s for key '%s'"
+                                   " (duplicate extraction, follow extractors order)" )
+                            _LOGGER.warning(
+                                msg,
+                                found_value,
+                                key_extractor,
+                                attr
+                            )
+                            continue
                         raw_value = found_value
 
                 value = self.deserialize_data(raw_value, attr_desc['type'])

tests/test_serialization.py

@@ -1436,6 +1436,33 @@ def assert_model(inst):
         self.TestObj.from_dict(attr_data)
         assert_model(model_instance)
 
+    def test_twice_key_scenario(self):
+        # Te reproduce the initial bug, you need a attribute named after the last part
+        # of a flattening JSON from another attribute (here type)
+        # https://github.com/Azure/azure-sdk-for-python/issues/11422
+        # Issue happend where searching for "type2", since we found a match in both "type2" and "type" keys
+
+        class LocalModel(Model):
+            _attribute_map = {
+                'id': {'key': 'id', 'type': 'int'},
+                'type': {'key': 'type_dont_matter_not_used', 'type': 'str'},
+                'type2': {'key': 'properties.type', 'type': 'str'},
+            }
+
+            def __init__(self, **kwargs):
+                super(LocalModel, self).__init__(**kwargs)
+
+        raw = {
+            'id': 42,
+            'type': "type",
+            'type2': "type2"
+        }
+
+        m = LocalModel.from_dict(raw)
+        assert m.id == 42
+        assert m.type == "type"
+        assert m.type2 == "type2"
+
     def test_array_deserialize(self):
         result = self.d('[str]', ["a","b"])
         assert result == ['a','b']
@@ -1503,13 +1530,21 @@ class TestKeyTypeObj(Model):
         self.assertEqual(3, obj.attr_c)
         self.assertEqual(4, obj.attr_d)
 
-        with self.assertRaises(DeserializationError):
-            obj = TestKeyTypeObj.from_dict({
-                "attr_b": 1,
-                "id": 2,
-                "keyc": 3,
-                "keyd": 4
-            })
+        # This one used to raise an exception, but after https://github.com/Azure/msrest-for-python/pull/204
+        # we decide to accept it with log warning
+
+        obj = TestKeyTypeObj.from_dict({
+            "attr_a": 1,
+            "attr_b": 12, # Conflict with "id"
+            "id": 14, # Conflict with "attr_b"
+            "keyc": 3,
+            "keyd": 4
+        })
+
+        self.assertEqual(1, obj.attr_a)
+        self.assertEqual(12, obj.attr_b)  # from_dict will prioritize attribute syntax
+        self.assertEqual(3, obj.attr_c)
+        self.assertEqual(4, obj.attr_d)
 
     def test_basic_deserialization(self):
         class TestObj(Model):