Make Struct isset work in thrift-py3 auto-migrate

Summary:
This makes it so that calling `thrift.py3.Struct.isset` works on thrift-python structs.

I saw these failing unit tests while working on making the instance checks work, and I figured this would only be a few lines of code required to fix it.

Reviewed By: prakashgayasen, ahilger

Differential Revision: D68811683

fbshipit-source-id: 52b853bbe829a42cd50755f9d1ca24c76df9958c

Author: Filip Francetic

thrift/lib/py3/test/auto_migrate/converter.py

@@ -418,7 +418,6 @@ def test_complex_union_capi(self) -> None:
         self.assertEqual(complex_union.type, py3_types.Union.Type.simple_)
         self.assertEqual(complex_union.simple_.intField, 42)
 
-    @brokenInAutoMigrate()
     def test_optional_defaults(self) -> None:
         converted = python_types.OptionalDefaultsStruct()._to_py3()
         # pyre-fixme[6]: Expected `HasIsSet[Variable[thrift.py3.py3_types._T]]` for 1st

thrift/lib/py3/test/auto_migrate/structs.py

@@ -51,7 +51,6 @@
 
 
 class StructTests(unittest.TestCase):
-    @brokenInAutoMigrate()
     def test_isset_Struct(self) -> None:
         serialized = b'{"name":"/dev/null","type":8}'
         file = deserialize(File, serialized, protocol=Protocol.JSON)
@@ -73,7 +72,6 @@ def test_isset_Struct(self) -> None:
         #  param but got `File`.
         self.assertFalse(Struct.isset(file).type)
 
-    @brokenInAutoMigrate()
     def test_isset_repr(self) -> None:
         serialized = b'{"name":"/dev/null","type":8}'
         file = deserialize(File, serialized, protocol=Protocol.JSON)
@@ -97,7 +95,6 @@ def test_isset_Union(self) -> None:
             #  1st param but got `Integers`.
             Struct.isset(i).large
 
-    @brokenInAutoMigrate()
     def test_isset_Error(self) -> None:
         e = UnusedError()
         # pyre-fixme[6]: Expected `HasIsSet[Variable[thrift.py3.types._T]]` for 1st

thrift/lib/py3/types.pyx

@@ -26,6 +26,7 @@ from folly.iobuf import IOBuf
 from types import MappingProxyType
 
 from thrift.py3.exceptions cimport GeneratedError
+from thrift.python.exceptions cimport GeneratedError as _fbthrift_python_GeneratedError
 from thrift.py3.serializer import deserialize, serialize
 from thrift.python.types cimport (
     BadEnum as _fbthrift_python_BadEnum,
@@ -37,6 +38,7 @@ from thrift.python.types import (
     Flag as _fbthrift_python_Flag,
     Struct as _fbthrift_python_Struct,
     StructOrUnion as _fbthrift_python_StructOrUnion,
+    isset as _fbthrift_python_isset,
     Union as _fbthrift_python_Union,
 )
 
@@ -49,10 +51,6 @@ __all__ = ['Struct', 'BadEnum', 'Union', 'Enum', 'Flag', 'EnumMeta']
 
 _fbthrift__module_name__ = "thrift.py3.types"
 
-# This isn't exposed to the module dict
-Object = cython.fused_type(Struct, GeneratedError)
-
-
 cdef list_eq(List self, object other):
     if (
         not isinstance(other, Iterable) or
@@ -85,8 +83,13 @@ cdef class StructMeta(type):
     We set helper functions here since they can't possibly confict with field names
     """
     @staticmethod
-    def isset(Object struct):
-        return struct._fbthrift_isset()
+    def isset(struct):
+        if isinstance(struct, (_fbthrift_python_Struct, _fbthrift_python_GeneratedError, _fbthrift_python_Union)):
+            return _IsSet(type(struct).__name__, _fbthrift_python_isset(struct))
+        elif isinstance(struct, Struct):
+            return (<Struct>struct)._fbthrift_isset()
+        elif isinstance(struct, GeneratedError):
+            return (<GeneratedError>struct)._fbthrift_isset()
 
     @staticmethod
     def update_nested_field(obj, path_to_values):