From a94dc073fd582cf0a78a6c3e616222fdce11572a Mon Sep 17 00:00:00 2001
From: Jelle Zijlstra <jelle.zijlstra@gmail.com>
Date: Sun, 16 May 2021 11:42:24 -0700
Subject: [PATCH] Remove assertion from TypeGuard serialization

This came up in python/typeshed#5473: mypy started crashing when
I made a function return TypeGuard[Type[Any]]. I wasn't able to
reproduce this locally so far, but verified that removing the
assertion fixes the crash.
---
 mypy/types.py | 2 --
 1 file changed, 2 deletions(-)

diff --git a/mypy/types.py b/mypy/types.py
index bf138f343b5a..4587dadfd885 100644
--- a/mypy/types.py
+++ b/mypy/types.py
@@ -1271,8 +1271,6 @@ def __eq__(self, other: object) -> bool:
     def serialize(self) -> JsonDict:
         # TODO: As an optimization, leave out everything related to
         # generic functions for non-generic functions.
-        assert (self.type_guard is None
-                or isinstance(get_proper_type(self.type_guard), Instance)), str(self.type_guard)
         return {'.class': 'CallableType',
                 'arg_types': [t.serialize() for t in self.arg_types],
                 'arg_kinds': self.arg_kinds,