From 88d5aacf23a5551f5556ab16c452b6cd469d5430 Mon Sep 17 00:00:00 2001
From: BobTheBuidler <bobthebuidlerdefi@gmail.com>
Date: Thu, 2 Oct 2025 01:00:38 +0000
Subject: [PATCH 1/3] [mypyc] feat: support constant folding in
 `MessageBuilder.incompatible_argument`

---
 mypy/messages.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/mypy/messages.py b/mypy/messages.py
index 6329cad687f6..c850cd90d9fe 100644
--- a/mypy/messages.py
+++ b/mypy/messages.py
@@ -808,10 +808,10 @@ def incompatible_argument(
                     )
                     arg_label = f'"{arg_name}"'
                 if isinstance(outer_context, IndexExpr) and isinstance(
-                    outer_context.index, StrExpr
+                    index := constant_fold_expr(outer_context.index, "unused"), str
                 ):
                     msg = 'Value of "{}" has incompatible type {}; expected {}'.format(
-                        outer_context.index.value,
+                        index,
                         quote_type_string(arg_type_str),
                         quote_type_string(expected_type_str),
                     )

From a2605ad95f9059ad08f54054f4f1e35495bf91a2 Mon Sep 17 00:00:00 2001
From: "pre-commit-ci[bot]"
 <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Date: Thu, 2 Oct 2025 01:09:59 +0000
Subject: [PATCH 2/3] [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci
---
 mypy/messages.py | 1 -
 1 file changed, 1 deletion(-)

diff --git a/mypy/messages.py b/mypy/messages.py
index c850cd90d9fe..535041fcd0de 100644
--- a/mypy/messages.py
+++ b/mypy/messages.py
@@ -50,7 +50,6 @@
     MypyFile,
     NameExpr,
     ReturnStmt,
-    StrExpr,
     SymbolNode,
     SymbolTable,
     TypeInfo,

From 175d5d46b8643e07219145339241b717ce14c196 Mon Sep 17 00:00:00 2001
From: BobTheBuidler <70677534+BobTheBuidler@users.noreply.github.com>
Date: Wed, 1 Oct 2025 21:14:08 -0400
Subject: [PATCH 3/3] Update messages.py

---
 mypy/messages.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/mypy/messages.py b/mypy/messages.py
index 535041fcd0de..9b683143d68a 100644
--- a/mypy/messages.py
+++ b/mypy/messages.py
@@ -21,6 +21,7 @@
 
 import mypy.typeops
 from mypy import errorcodes as codes, message_registry
+from mypy.constant_fold import constant_fold_expr
 from mypy.erasetype import erase_type
 from mypy.errorcodes import ErrorCode
 from mypy.errors import (
@@ -807,7 +808,7 @@ def incompatible_argument(
                     )
                     arg_label = f'"{arg_name}"'
                 if isinstance(outer_context, IndexExpr) and isinstance(
-                    index := constant_fold_expr(outer_context.index, "unused"), str
+                    index := constant_fold_expr(outer_context.index, "<unused>"), str
                 ):
                     msg = 'Value of "{}" has incompatible type {}; expected {}'.format(
                         index,