Address review

Author: AlexWaygood

mypy/expandtype.py

@@ -307,22 +307,24 @@ def interpolate_args_for_unpack(self, t: CallableType, var_arg: UnpackType) -> l
         suffix = self.expand_types(t.arg_types[star_index + 1 :])
 
         var_arg_type = get_proper_type(var_arg.type)
-        if isinstance(var_arg_type, TupleType):
-            # We have something like Unpack[Tuple[Unpack[Ts], X1, X2]]
-            expanded_tuple = var_arg_type.accept(self)
-            assert isinstance(expanded_tuple, ProperType) and isinstance(expanded_tuple, TupleType)
-            expanded_items = expanded_tuple.items
-            fallback = var_arg_type.partial_fallback
-        elif isinstance(var_arg_type, Instance):
-            # We have something like Unpack[Tuple[Any, ...]]
-            expanded_items = list(var_arg_type.args)
-            fallback = var_arg_type
+        if isinstance(var_arg_type, Instance):
+            # we have something like Unpack[Tuple[Any, ...]]
+            new_unpack = var_arg
         else:
-            # We have plain Unpack[Ts]
-            assert isinstance(var_arg_type, TypeVarTupleType), type(var_arg_type)
-            fallback = var_arg_type.tuple_fallback
-            expanded_items = self.expand_unpack(var_arg)
-        new_unpack = UnpackType(TupleType(expanded_items, fallback))
+            if isinstance(var_arg_type, TupleType):
+                # We have something like Unpack[Tuple[Unpack[Ts], X1, X2]]
+                expanded_tuple = var_arg_type.accept(self)
+                assert isinstance(expanded_tuple, ProperType) and isinstance(
+                    expanded_tuple, TupleType
+                )
+                expanded_items = expanded_tuple.items
+                fallback = var_arg_type.partial_fallback
+            else:
+                # We have plain Unpack[Ts]
+                assert isinstance(var_arg_type, TypeVarTupleType), type(var_arg_type)
+                fallback = var_arg_type.tuple_fallback
+                expanded_items = self.expand_unpack(var_arg)
+            new_unpack = UnpackType(TupleType(expanded_items, fallback))
         return prefix + [new_unpack] + suffix
 
     def visit_callable_type(self, t: CallableType) -> CallableType: