create_autospec for mutable types

Summary: Add checks to prevent crash

Reviewed By: aristidisp

Differential Revision: D62579992

fbshipit-source-id: 99f37e27ae79b39df3ef64b99659bd89d56ce3d7

third-party/thrift/src/thrift/lib/python/mutable_types.pyx

@@ -108,12 +108,18 @@ class _MutableStructField:
         self._field_index = field_id
 
     def __get__(self, obj, objtype):
+        if obj is None:
+            return None
+
         if isinstance(obj, MutableStruct):
             return (<MutableStruct>obj)._fbthrift_get_field_value(self._field_index)
         else:
             return (<MutableGeneratedError>obj)._fbthrift_get_field_value(self._field_index)
 
     def __set__(self, obj, value):
+        if obj is None:
+            return
+
         if isinstance(obj, MutableStruct):
             (<MutableStruct>obj)._fbthrift_set_field_value(self._field_index, value)
         else:
@@ -136,12 +142,18 @@ class _MutableStructCachedField:
         self._field_index = field_id
 
     def __get__(self, obj, objtype):
+        if obj is None:
+            return None
+
         if isinstance(obj, MutableStruct):
             return (<MutableStruct>obj)._fbthrift_get_cached_field_value(self._field_index)
         else:
             return (<MutableGeneratedError>obj)._fbthrift_get_cached_field_value(self._field_index)
 
     def __set__(self, obj, value):
+        if obj is None:
+            return
+
         if isinstance(obj, MutableStruct):
             (<MutableStruct>obj)._fbthrift_set_field_value(self._field_index, value)
         else:
@@ -946,6 +958,9 @@ cdef class _MutableUnionFieldDescriptor:
 
         Raises error if this field is not currently set on the given `union_instance`.
         """
+        if union_instance is None:
+            return None
+
         field_info = self._field_info
         cdef int field_id = self._field_info.id
 
@@ -978,6 +993,9 @@ cdef class _MutableUnionFieldDescriptor:
                 `TypeInfoBase`). If this field is adapted, this value should be in the
                 adapted type (as opposed to the underlying Thrift type).
         """
+        if union_instance is None:
+            return
+
         field_info = self._field_info
         cdef int field_id = self._field_info.id
 

third-party/thrift/src/thrift/lib/python/test/structs.py

@@ -328,6 +328,12 @@ def test_repr(self) -> None:
             repr(self.easy(val=42)),
         )
 
+    def test_autospec_iterable(self) -> None:
+        for _ in mock.create_autospec(self.easy):
+            pass
+        for _ in mock.create_autospec(self.easy()):
+            pass
+
 
 class StructTestsImmutable(unittest.TestCase):
     """
@@ -357,12 +363,6 @@ def test_copy(self) -> None:
         dif_int = copy.copy(x.an_int)
         self.assertEqual(x.an_int, dif_int)
 
-    def test_autospec_iterable(self) -> None:
-        for _ in mock.create_autospec(easy):
-            pass
-        for _ in mock.create_autospec(easy()):
-            pass
-
     def test_update_nested_fields(self) -> None:
         n = Nested1(a=Nested2(b=Nested3(c=easy(val=42, name="foo"))))
         n = update_nested_field(n, {"a.b.c": easy(val=128)})