fix failsafe deserialization (#234)

* fix failsafe deserialization

* add extra checks

* fix changelog

Author: iscai-msft

README.rst

@@ -20,6 +20,13 @@ To install:
 Release History
 ---------------
 
+2021-01-26 Version 0.6.21
++++++++++++++++++++++++++
+
+**Bug Fixes**
+
+- Fixes `failsafe_deserialize` introduced in `0.6.20` #232
+
 2021-01-25 Version 0.6.20
 +++++++++++++++++++++++++
 

msrest/serialization.py

@@ -1486,7 +1486,7 @@ def _classify_target(self, target, data):
             pass  # Target is not a Model, no classify
         return target, target.__class__.__name__
 
-    def failsafe_deserialize(self, target_obj, response_data, content_type=None):
+    def failsafe_deserialize(self, target_obj, data, content_type=None):
         """Ignores any errors encountered in deserialization,
         and falls back to not deserializing the object. Recommended
         for use in error deserialization, as we want to return the

msrest/version.py

@@ -25,4 +25,4 @@
 # --------------------------------------------------------------------------
 
 #: version of this package. Use msrest.__version__ instead
-msrest_version = "0.6.20"
+msrest_version = "0.6.21"

setup.py

@@ -28,7 +28,7 @@
 
 setup(
     name='msrest',
-    version='0.6.20',
+    version='0.6.21',
     author='Microsoft Corporation',
     packages=find_packages(exclude=["tests", "tests.*"]),
     url=("https://github.com/Azure/msrest-for-python"),

tests/test_serialization.py

@@ -2536,16 +2536,30 @@ class TestModel(Model):
     def test_failsafe_deserialization(self):
         class Error(Model):
 
+            _attribute_map = {
+                "status": {"key": "status", "type": "int"},
+                "message": {"key": "message", "type": "str"},
+            }
+
             def __init__(self, **kwargs):
-                self.status = kwargs.pop("status")
-                self.message = kwargs.pop("message")
+                super(Error, self).__init__(**kwargs)
+                self.status = kwargs.get("status", None)
+                self.message = kwargs.get("message", None)
+
 
         with pytest.raises(DeserializationError):
             self.d(Error, json.dumps(''), 'text/html')
 
+        # should fail
         deserialized = self.d.failsafe_deserialize(Error, json.dumps(''), 'text/html')
         assert deserialized is None
 
+        # should not fail
+        error = {"status": 400, "message": "should deserialize"}
+        deserialized = self.d.failsafe_deserialize(Error, json.dumps(error), 'application/json')
+        assert deserialized.status == 400
+        assert deserialized.message == "should deserialize"
+
 class TestModelInstanceEquality(unittest.TestCase):
 
     def test_model_instance_equality(self):